BENDIX BW1460 User's Manual
Contents
1. COMPACT 500 INTEGRAL HYDRAULIC POWER STEERING GEAR P SD 30 4250 FOR FORD MOTOR CO CARGO VEHICLES I DESCRIPTION The Compact 500 Hydraulic Power Steering gear is designed for heavy duty vehicles with front axle weight ratings of up to 15 000 Ibs It is an integral power steering gear incorporating the mechanical and hydraulic actuation and control components in a single cast housing which serves as the power cylinder The vehicle s steering column is coupled to the gear at the input shaft which transmits steering effort through a recirculating ball screw and piston nut The piston nut is an integral part of the power assist piston and also acts as a steering damper The direction and degree of power assist is controlled by a rotary hydraulic valve which is integral to the input shaft and supplied by an engine driven hydraulic pump This valve design assures light responsive steering while maintaining a mechanical connection between the steering column and the ball screw Il OPERATION GENERAL The C 500 integral power steering gear is composed both of mechanical steering components and hydraulic power assist components Actual steering is accomplished mechanically Effort applied at the vehicle s steering wheel results in mechanical movement within the steering gear which causes the vehicle to change its direction of travel The hydraulic power assist components function solely to reduce the effort required to turn th2. depth in both holes of the piston See Figure 38 This will assure correct installation of the return tube 49 Install the seven remaining balls 29 into the ball return tube halves 49 using lithium base general purpose grease Ford Chassis grease ESA M1C75 B to retain the balls Place the tube into piston 48 install the tube cover 50 and its snap ring 51 Check for smooth operation of the spindle assembly See Figure 39 NOTE the utmost care must be taken with these steps Incorrect assembly of this group may result in one or more balls failing inside the piston or coming out at the top of it and lodging in the bottom of the housing 45 Install the O Ring 47 and back up rings 46 on the piston See Figures 36 amp 40 FIGURE 38 FIGURE 39 FIGURE 40 NOTE Make certain to rotate the glide rings 46 so that their gaps are 180 apart and not in line with each other HOUSING ASSEMBLY 6 Ifthe outer race of bearing 26 was removed it must be reinstalled using tool 297677 Center the narrow bearing spacer on tool 297677 then install the bearing 26 complete with its outer race 26 on the tool Drive the bearing and race along with the spacer into the housing from the output shaft side of the housing until the tool bottoms against the outside of the housing See Figures 41A B amp C Remove the tool and check to be certain that the outer race and spacer have been driven into the housing sufficiently deep
3. reaches 130 F 55 C record flow rate and pressure A If flow is below 3 5 g p m 13 2 L min Check to see if correct pump is installed If correct continue testing to find problem B If pressure exceeds 80 p s i 552 kPa check lines for kinks or obstructions If none are found and pressure remains high continue testing to find problem MINIMUM PUMP FLOW 1 Decrease engine speed to 600 rpm 2 Slowly close shutoff valve to increase pressure to 1200 p s i Record flow rate at 130 F 55 C If flow rate is below 2 2 g p m 8 3 L min then verify correct pump is installed Pump may require repair or replacement especially if flow at 2200 r p m was also below specification RELIEF PRESSURE TEST POWER STEERING PUMP 1 With the engine running at 600 r p m close the shutoff valve and read the pressure gauge and note the flow rate is 0 OPEN THE SHUTOFF VALVE QUICKLY after reading the gauge pressure and note the flow rate returns to normal If the pressure reading is below 1800 p s i or above 2250 p s i repair or replacement of the relief valve is necessary CAUTION The shutoff valve must not remain closed longer than FIVE SECONDS or damage to the pump may result 23 2 Allow the power steering pump fluid to cool to 130 F before testing is resumed 3 With the engine at full governed R P M close the shutoff valve and note that the flow reads 0 QUICKLY OPEN THE SHUTOFF VALVE and note that the flow r
4. unseated and some hydraulic power assist is removed as pressurized oil is diverted to the return line As more and more power assist is removed by the action of the limiting poppet valves steering effort increases The piston can travel to the extreme ends of its bore however the maximum steering assistance available is reduced to protect the steering components in the axle The bypass valve is located in the valve body and permits oil to flow from one side of the piston to the other when it is necessary to steer the vehicle without the hydraulic pump STRAIGHT AHEAD RETURN BY PASS VALVE RIGHT TURN in operation Oil displaced from one side of the piston is essentially transferred to the other side which prevents reservoir flooding and cavitation in the pressure line The pressure relief valve is located in the valve body and limits internal hydraulic pressure to a preset maximum The pressure relief valve can be setto various pressures however its setting is 150 p s i lower than the power steering pump relief valve setting POWER STEERING GEAR IDENTIFICATION A nameplate is installed adjacent to one of the mounting lugs of the unit which indicates part number serial number and build date Ill TECHNICAL DATA Steering RECH EE 21 1 Number of turns of the steering wheel 5 25 Turning angle on the output shaft 90 2 Output shaft torque obtained with an effective p
5. valve 8 With a wide blade screwdriver loosen and remove the valve seat 9 and its copper seal washer 10 as well as the spring 11 and the ball 12 of the bypass valve NOTE Be careful not to damage the I D of the valve body or the valve seat 9 with the screwdriver 15 FIGURE 28 FIGURE 29 16 OUTPUT SHAFT DISASSEMBLY 20 Remove the snap ring 38 the adjusting screw spacer 37 and the adjusting screw 36 from output shaft See Figure 29 SPINDLE DISASSEMBLY CAUTION Do not attempt disassembly of the spindle assembly which contains the rotary valve Individual replacement parts are NOT available for this assembly It must be treated as a single component CLEANING AND INSPECTION CLEANING Wash all parts individually in clean solvent and dry thoroughly All non metallic parts should be discarded and replaced with new INSPECTION Visually inspect all parts carefully paying particular attention to 1 Bearings and bearing surfaces including inner and outer races and balls 2 Sector gear and piston teeth 3 Output and input shaft Exterior of spindle and interior of piston and recirculating balls 5 Exterior of piston and housing bore NOTE Minor scuffing of the piston exterior and housing bore can be considered normal If deep Scoring is detected the affected parts should be replaced as leakage will occur and steering control and reaction will be affected Do not attempt honing or boring of t
6. 4 24 25 25 27 LEFT TURN RIGHT TURN D STEERING 7 BALLSCREW WHEEL n d PISTON NUT RECIRCULATING BALLS PITMAN ARM POWERCYLINDER FIGURE 1 MECHANICAL OPERATION a screw and nut through the action of the chain of recirculating balls that serve as an interface Rotation of the ball screw causes axial movement of the piston within the power cylinder Gear teeth cut directly into the piston mesh with corresponding sector gear teeth on the output shaft and as the piston moves the output shaft and attached pitman arm are rotated HYDRAULIC OPERATION The driven end of the ball screw rotates on a ball bearing contained in the valve body Hydraulic pressure enters and exits the power steering gear through lines connected to threaded ports in the valve body A pressure relief valve contained in the valve body prevents overpressurization of the power steering gear Hydraulic pressure in excess of the setting of the relief valve causes the valve to open a channel to the reservoir return side of the gear The ball screw assembly is retained in the valve housing by a valve nut which forms the outermost element of the rotary control valve The valve nut contains circular channels and radial passages which serve to direct hydraulic oil into and out ofthe rotary control valve The ball screw assembly forms the rotary control and consists of three parts the input shaft torsion bar and ball screw One end of the input
7. AFT SECTOR TEETH ADJUSTMENT The gear lash between the piston teeth and sector gear should not require attention in normal service however a provision for adjustment is provided Adjustment requires that the steering gear be drained and the pitman arm and input shaft disconnected from the vehicle The adjustment procedure is described at the end of the assembly section of this manual OUTPUT SHAFT BOOT SEAL Inspect the integrity of the output shaft boot seal located between the pitman arm and housing This component prevents contamination from entering the output shaft bearing andretains grease on the bearing and output shaft to prevent corrosion If deterioration or leakage is detected it should be replaced 297675 297660 V IMPORTANT PLEASE READ When working on or around the Power Steering system and components the following precautions should be observed 1 Always block vehicle wheels Stop engine when working under a vehicle Keep hands away from pinch points 2 Never connect or disconnect a hose or line containing pressure Never remove a component or pipe plug unless you are certain all system pressure has been depleted 3 Never exceed recommended pressure and always wear safety glasses 4 Never attempt to disassemble a component until you have read and understood recommended procedures Use only the proper tools and observe all precautions pertaining to use of those tools 5 Use only genuine Bendix repl
8. GURE 24 SIDE COVER DISASSEMBLY 15 Remove O ring 40 and seal 39 See Figure 24 NOTE Do not attempt to remove the bearing The side cover MUST BE replaced if it is determined that the bearing requires replacement The side cover is supplied with the bearing factory installed VALVE BODY AND SPINDLE DISASSEMBLY 16 With a drift punch unblock the safety point between valve nut 33 and valve body 16 Loosen and remove the valve nut with spanner wrench 297661 and remove the spindle assembly 34 the ball race 28 the ball cage 30 and the seventeen bearing balls See Figure 25 FIGURE 25 14 oe 1941 9 8 7 6 Per i i f Ef ed Aule Leen FIGURE 26 17 Remove the inner O ring 17 and the nylon seal ring 18 from the valve body 16 NOTE Do not remove the inner ball race 28 from the valve body 16 if itis in good condition 18 Then remove the dust seal 13 snap ring 14 and the seal 15 from the valve body 16 See Figures 7 amp 26 PRESSURE RELIEF BYPASS VALVE DISASSEMBLY 19 The power steering valve body 16 contains a pressure relief and safety valve Loosen and remove the plug 3 with a 26mm wrench FIGURE 27 and the corresponding seal washer 4 CAUTION Located in the plug are the corresponding maximum pressure adjusting shims 5 See Figure 27 amp 28 Proper reinstallation of the shims is critical to maintain correct relief pressure Remove the spring 6 the guide 7 and the
9. POWER STEERING PUMP MEA VALVE FIGURE 49 24 4 5 FIGURE 50 1945 p s i or below 1825 p s i relief valve adjustment or repair is necessary CAUTION When running this test do not hold the torque on the steering wheel for more than 5 seconds beyond the time the pressure relief setting of the gear has been reached It may damage the unit or cause the temperature of the oil to raise beyond 200 In order to test the steering gear for internal leakage it is necessary to TEMPORARILY adjust the setting of the power steering gear pressure relief valve above that of the power steering pump relief valve To accomplish this install the appendix pressure relief valve test plug assembly 106773 To install the plug assembly See Figure 7 A With the engine stopped remove the pressure relief valve plug 3 sealing washer 4 adjusting shims 5 and spring 6 B Install the sealing washer on the test plug assembly 106773 then install the test plug assembly in the power steering gear valve body Torque the test plug assembly to 66 73 pound feet Run the engine at idle Turn the steering wheel until the axle stop contacts the spacer block See Figure 50 Apply a sufficient torque to the steering wheel to assure the power steering gear control valve is completely open in the direction of the turn Observe the following PART NUMBER 106773 PRESSURE RELIEF VALVE TEST PLUG ASSEMBLY A Gauge pressure should read the sam
10. STOP BALL BEARING CN Bendix 2268000 709G5 ESHT3K500AA FABRICADO PELA BENDIX DO BRASIL Clean the outside of the reservoir Remove the old filter element Oil the filter support and assemble with a new filter Fill reservoir full of oil Turn the engine over with the starter motor Must be done in a manner that the engine does not start Add oil as the level drops to avoid air being drawn into the system RECIRCULATING SPINDLE BALL SCREW HOUSING VM SEAL amp GLIDE OUTPUT SHAFT SECTOR GEAR P PITMAN ARM NUT NEEDLE BEARING TORSION BAR O RING 3 FIGURE 5 6 OUTPUT SHAFT x Or Ll 297676 297661 E M o 297674 FIGURE 6 REQUIRED TOOLS 6 When the oil level reaches the full mark on the dipstick start the engine and turn the steering wheel slowly from side to side until air bubbles cease to appear in the reservoir Refill reservoir to full mark on the dipstick 7 The oil level should be checked every 2 000 miles The correct level is between the minimum and maximum level marks on the dipstick with the engine stopped CHANGE INTERVALS It is recommended that the oil be changed at 40 000 mile intervals and at the time of rebuild Beyond its function as the media for transmitting power the oil also serves to lubricate and dissipate heat Carefully clean inspect and replace if necessary all filter elements in the pump system including vents and breathers OUTPUT SH
11. Shaft Adjusting Screw be C4 31 Output Shaft Adjusting Screw Shim Washer Snap Ring Side Cover Output Shaft Seal Side Cover O Ring Side Cover Assy includes Needle Bearing AsSy Side Cover Bolt Output Shaft Adjusting Screw Lock Nut Housing Drain Plug Housing Piston Backup Ring Piston O Ring Piston Recirculating Ball Tube Ball Tube Cover Snap Ring Piston Limiting Body Nut Piston Limiting Body and Valve Seat Piston Limiting Stem Short Piston Limiting Stem Long Limiting Body Stop Washer Limiting Valve Spring erro O e j 37 38 40 FIGURE 7 4 Separate the valve body from the housing by rotating the output shaft using the pitman arm if it has not been previously removed Continue to separate the valve body from the housing until one of the O ring seals is visible NOTE It may be necessary to hold or rotate the input shaft to perform this operation See Figure 10 FIGURE 10 5 Remove the pitman arm by unbending the nut lock 21 and remove the pitman arm fastening nut Remove the pitman arm using a large gear puller such as the Snap On CG 283 or Ford part number T64P 3590 F CAUTION Do not use heat or pound on the pitman arm or output shaft as damage can result These components must be replaced rather than repaired if they are damaged Remove any accumulated dirt grease grime and corrosion from the exposed portion of the output shaft to facilitate removal through
12. acement parts and components A Only components devices and mounting and attaching hardware specifically designed for use in hydraulic systems should be used B Replacement hardware tubing hose fittings etc should be of equivalent size type and strength as the original equipment 6 Devices with stripped threads or damaged parts should be replaced Repairs requiring machining should not be attempted VI REMOVING THE POWER STEERING GEAR 1 Mark or identify the inlet and return lines at the valve body ports 2 Drain the system following the instructions presented under preventive maintenance Remove both inlet and return lines 3 Disconnect the steering column at the input shaft following the vehicle manufacturer s instructions 4 Disconnect the pitman arm from the vehicle s steering linkage using the vehicle manufacturer s instructions CAUTION If itis necessary to remove the pitman before the steering gear can be removed from the vehicle DO NOT USE HEAT OR POUND ON THE PITMAN ARM OR OUTPUT SHAFT as damage can result Do not attempt repairs to these components They must be replaced if damaged Use a large gear puller to remove the pitman arm such as Snap On puller 4C G 283 or Ford part number T64P 3590 F 5 Remove the steering gear from the vehicle Vil SPECIAL TOOL REQUIREMENTS The following special tools are required to disassemble and assemble the power steering gear 297661 Spanner Wrench Used to r
13. ap ring 14 and dust seal 13 into valve body 16 See Figure 31 3 Using tool number 297647 install the inner ball race 28 in the event it was removed into the bottom of valve body and install internal O Ring 17 and the two external O Rings 19 See Figure 32 Install nylon seal 18 in FIGURE 32 FIGURE 33 the internal threaded portion of the valve body 16 See Figure 7 SPINDLE ASSEMBLY 4 Install the cage 30 on the input shaft end of the spindle 34 Install the outer ball race 28 and using a lithium base general purpose grease Ford Chassis grease ESA M1C75 B to hold them in place insert the 17 new balls 29 comprising the bearing Insert the assembly into the valve body See Figure 33 Remove from the valve nut 33 the three teflon glide seal rings 32 and the three O Rings 31 and install new ones When they are in their respective grooves insert the tool 297676 to seat them See Figure 34 NOTE Make certain the O rings and glide rings are in their proper grooves Refer to Figure 5 An oil channel separates each ring 297676 FIGURE 34 17 FIGURE 35 Without removing tool 297676 insert the nut 33 into the valve body 16 screw and tighten it to a torque of 330 ft Ibs with a spanner wrench See Figure 35 NOTE Tool 297676 for the teflon glide rings will come out as the nut is screwed into the valve body Lock the nut in the valve body by staking the edge of the valve nut in
14. ate immediately returns to normal Repeat this test once but do not allow fluid temperature to exceed 200 F If the flow rate does not immediately return to normal pump repair or replacement is indicated RELIEF PRESSURE TEST amp INTERNAL LEAKAGE TEST POWER STEERING GEAR 1 To test the pressure relief valve and internal leakage of the power steering gear it is necessary to prevent operation of the gear s poppet valves contained in the piston This can be accomplished by placing a steel block between the axle stop and the adjusting screw The block should be a minimum of one inch thick and long enough to be inserted without danger of pinching fingers Keep fingers clear of pinch points and be sure block is square to points of contact WARNING Failure to follow these instructions can result in serious injury or damage to the equipment 2 Check fluid temperature in the reservoir thermometer reading should be approximately 130 at start of the test and the shut off valve on the flow meter must be totally open NOTE Refer to Preliminary Instructions section of the service data 3 Turn the steering wheel until the axle stops contact the spacer block See Figure 50 Apply sufficient torque to the steering wheel to assure the power steering gear control valve is completely open in the direction of the turn At this time the pressure gauge will read the gear pressure relief setting If the pressure reading is above SHUTOFF
15. axle assembly Lower steering gear parts deformed as a result of accident or breakdown in the rotary valve unit Low tire pressure Bind in intermediate shafts Unsuitable oil Dirt inside the pressure pump Oil reservoir filter blocked Piping contacting part of the bodywork causing vibrations particularly the pressure feed pipe Reservoir oil level low REMEDY Check pump to performance specification Overhaul by authorized workshop if required Check oil level Change oil Clean and dry the outside of the power steering body and take the vehicle out on test to locate the leak Tighten or replace Check pump to performance specifications Overhaul by authorized workshop Replace incorrect or unserviceable hoses Replace incorrect or unserviceable hoses Lubricate front axle assembly Check for damaged or worn parts Replace the ball screw assembly Inflate tires to correct pressure Determine cause and correct Drain oil and fill up with recommended grade Overhaul by authorized workshop Replace filter Space pipe from bodywork If not possible insulate with a rubber spacer Fill up to level and check installation BW1450 2002 Bendix Commercial Vehicle Systems LLC All rights reserved 3 2002 Printed in U S A 27
16. ble which do not require full disassembly The instructions provided with these parts and kits should be followed in lieu of the instructions presented here OUTPUT SHAFT REMOVAL 1 After removing the power steering unit from the vehicle and cleaning the outside secure the power steering unit to the work bench for disassembly A large vise with jaw protectors may be used Clamp across the mounting bolt bosses Do not overtighten 2 Using a 17mm wrench remove the drain plug from the housing and drain out all oil Fig 8 3 Loosen and remove the four bolts 1 from the valve body with a 22mm socket See Figures 7 amp 9 297678 297647 Valve Body Bolt Washer Pressure Relief Valve Plug Sealing Washer Adjusting Washer Shim Pressure Relief Valve Spring Spring Guide Pressure Relief Valve Pr Noc Or ds esu cx Pressure Relief Valve Seat Sealing Washer By pass Ball Valve Spring By pass Ball Valve Input Shaft Dust Seal Snap Ring Input Shaft Seal Valve Body Housing Valve Body O Ring Valve Body Seal Ring Nylon Valve Body O Ring Pitman Arm Nut Pitman Arm Nut Lock Washer Pitman Arm Output Shaft Boot Boot Retainer Snap Ring Needle Bearing Assy Output Shaft Seal Valve Body amp Spindle Ball Bearing Outer Race Split Ball Ball Bearing Cage Valve Nut O Ring Valve Nut Teflon Glide Ring Valve Nut a 31 Spindle Assy Valve amp Ball Screw Assy Output Shaft 29 o 2E Output
17. e as the power steering pump relief pressure See Step 1 under Relief Pressure Test Power Steering Pump B With system pressure at pump relief read the flow meter If a flow greater than 3 5 quarts per minute is noted internal leakage is excessive and the steering gear requires repair 6 Repeat Test 5 turning the steering wheel in the opposite direction IMPORTANT Remove the pressure relief valve test plug assembly which was in Step 4 before placing the vehicle in service XI TROUBLESHOOTING PRELIMINARY CHECKS Before proceeding to the troubleshooting headings it is strongly recommended that some preliminary checks be made and a test ride be taken to eliminate unnecessary work 1 Check for proper and equal tire inflation on the steering axle Note any abnormal tire wear which may be attributable to front end alignment 2 Make certain the power steering reservoir oil level is correct 3 Makecertain the power steering pump belt is not slipping 4 Visually inspect the following components for obvious damage misadjustment and possible binding a steering column and universals or couplings b steering arms tie rods tie rod ends and knuckles c general looseness in the steering linkages 5 Check hoses for sharp bends kinks and proper size The most common faults may be grouped under the following headings 1 Power steering does not operate 2 The power steering is still in one direction and nor
18. e vehicle s steering wheel Loss of hydraulic power will in no way prevent the vehicle from being maneuvered mechanically however greater effort will be required to turn the steering wheel MECHANICAL OPERATION The turning effort exerted by the driver on the steering wheel is transmitted to the input shaft which is part of the ball screw assembly The ball screw and piston nut function like 1 VII VIII IX X Xl DESCRIPTION OPERATION On gt 4 TECHNICAL DATA TABLE OF CONTENTS General Mechanical Parts Hydraulic Parts Power Steering Identification PREVENTIVE MAINTENANCE 1 2 3 4 5 CAUTION NOTE REMOVAL Power Steering Oil Draining and Filling the System Change Intervals Output Shaft Sector Teeth Adjustment Output Shaft Boot Seal SPECIAL TOOL REQUIREMENTS DISASSEMBLY 1 c0 0o90 amp oN REASSEMBLY Dm Joo ko General Piston Main housing Side cover Valve Body Pressure Relief Valve Output shaft Cleaning Inspection Valve body Spindle assembly Piston Main housing Housing and valve body Output shaft Side cover Housing and side cover Adjustment of output shaft backlash PRESSURE FLOW amp LEAKAGE TESTS 1 2 Relief Pressure Test Power Steering Pump Relief Pressure Test Power Steering Gear TROUBLESHOOTING Page No Ge AN JI N dn bb ob OO Om Om Om E amp 16 23 16 17 17 18 19 20 21 21 22 23 23 23 25 2
19. emove and replace the valve nut 297676 Seating Tool Used to assure seating and prevent damage to the teflon glide seal rings in the valve nut during reassembly 297674 Piloted Seal Tool Used to seat the seal and spacer in the body of the power steering gear 297675 Piloted Seal Tool Used to seat the seal in the end cover 297660 Poppet Wrench Used to remove and install limiting valve poppets The following special tools are available and are useful but not required for routine disassembly assembly of the power steering gear unless replacement of the bearing races is required 297677 FIGURE 6A NON REQUIRED TOOLS 8 297678 Holding Fixture Used to hold the piston and the valve assembly during disassembly and assembly Note Part No 297678 includes the holding fixture and spanner wrench 297661 297677 Piloted Bushing Tool Used to seat the bearing race in the main housing 297647 Piloted Bushing Tool Used to drive bearing race out of the main housing Also used to drive split bearing race into valve body Vill DISASSEMBLY GENERAL A high level of cleanliness should be observed at all times when working on the power steering gear Clean the exterior of all parts prior to disassembly The following disassembly and assembly procedure is presented for reference purposes and presupposes that a major rebuild of the power steering gear is being undertaken Several replacement parts and maintenance kits are availa
20. hese parts as leakage rates will increase 6 Pitman arm Housing and mounting lugs 8 Valve body and porting Parts found broken cracked distorted or fatigued must be replaced Cause for the replacement of any part should be investigated and corrected to prevent reoccurrence IX REASSEMBLING THE POWER STEERING UNIT To ensure a correct fault free operation of the power steering unit after all parts have been cleaned and faulty ones replaced the following assembly procedure should be followed The appropriate maintenance kit or kits should be obtained prior to assembly Should any ofthe 17 ball bearing balls require replacement replace them all at once proceed similarly in case any of the 26 recirculating balls need replacement Failure to follow this procedure strictly may result in a faulty operation of the power steering unit FIGURE 30 VALVE BODY REFER TO FIGURE 30 1 Place the valve body 16 in a vise and lightly tighten on the cast surface Install the ball 12 spring 11 valve seat 9 and the copper seal washer 10 Tighten with an appropriate screwdriver to a torque of 200 in lbs See Figure 30 NOTE Anew copper washer 4 must be used to assure correct sealing Install the relief valve rod 8 the guide 7 and the spring 6 Place the copper seal washer 4 onto the plug 3 with the corresponding adjusting shims 5 and tighten with 26 mm torque wrench Torque to 66 74 ft Ibs 2 Install the seal 15 sn
21. its seal See Figure 7 FIGURE 8 6 Loosen and remove the lock nut 43 from adjusting screw 36 on the side cover using a 24mm socket Remove the four bolts 42 from the side cover 41 with a 22mm socket See Figures 7 11 amp 12 7 Using a 9mm wrench turn the head of the adjusting screw 36 clockwise to lift the side cover out of the housing See Figure 13 FIGURE 9 FIGURE 11 10 FIGURE 14 FIGURE 12 8 Install the pitman arm and use it to center the piston and output shaft sector teeth inside cover opening Remove the pitman arm and then remove the output shaft by tapping gently on the splined end with a nylon mallet See Figures 14 amp 15 FIGURE 13 FIGURE 15 11 FIGURE 16 FIGURE 18 PISTON REMOVAL amp DISASSEMBLY body See Figure 17 Remove the O ring 47 and two 9 While preventing rotation of the input shaft remove the back up rings 46 from the piston groove See Figure spindle valve body and piston from the housing See 18 Remove the snap ring 51 and tube cover 50 and Figure 16 Remove the two O rings 19 from the valve lift out and remove both halves of the ball return tube 49 7 balls inside See Figure 19 FIGURE 17 FIGURE 19 12 FIGURE 20 Rotate the input shaft and spindle 34 counterclockwise to remove the remainder of the 26 internal balls 29 a small magnet is a useful tool for this operation Separate the piston from the spindle See Figure 21 Ho
22. lding FIGURE 21 FIGURE 22 10 11 12 13 FIGURE 23 fixture 297678 pictured is a convenience but not a necessity to disassemble and assemble the steering gear IMPORTANT Though being of the same size recirculating balls bearing balls and limiting valve balls must not be mixed or replaced with each other Mark or otherwise identify the limiting valve stems 54 amp 55 with regard to which end of the piston 48 each is located IMPORTANT These stems must be installed in the same end of the piston from which they are removed See Figure 7 Using the 6mm hollow hex wrench tool 297660 See Figure 6 installation on the valve stem 54 until the hex of the wrench engages the hex of the limiting body nut 52 Using a6mm socket to turn the hex wrench remove the nut 52 body 53 stem 54 ball valve 29 stop washer 56 and spring 57 The ball valve 29 and stem 55 may also be removed Remove the limiting body nut 52 limiting body 53 and stop washer 56 from the other end of the piston 48 HOUSING DISASSEMBLY 14 Remove the rubber boot 23 and boot retainer 24 from the main housing 45 See Figure 22 Take out the snap ring 25 and extract bearing assy 26 and seal 27 See Figure 23 NOTE Do not remove the outer bearing race if in good condition If it is necessary to remove the outer bearing race use tool 297647 and drive the race into the housing 45 until it is free 13 FI
23. mal in the other 3 The power steering tends to turn itself when the engine is started Excessive free play at the steering wheel 5 The power steering operates normally but is intermittently hard 6 Oilleaks 7 The power steering is still when turning the steering wheel quickly 8 The power steering does not return correctly 9 The power steering operates but with noise turbulence or vibration 25 1 2 3 4 26 SYMPTOM Power steering does not operate Power steering stiff in one direction and normal in the other Power steering tends to turn by itself when engine is running Excessive free play in steering wheel TROUBLESHOOTING CHART CAUSE A Lowoil level B Air in system C The pressure pump does not supply an adequate flow or pressure D Obstruction in the oil reservoir outlet or inlet E Communication between sides of power steering piston F Mechanical faults in vehicle steering members not belonging to power steering gear G Low pressure in front tires H Relief valve opens at low pressure L Faulty operation of the rotary valve A No pressure being applied to top or bottom side of power steering piston B Faulty operation of the rotary valve C Mechanical fault in vehicle steering members not belonging to power steering units D Excess leakage through piston limiting valve in one direction A Rotary valve incorrectly set A Po
24. nce is removed As the ball screw rotates the relative groove INPUT SHAFT BEARING OIL OUTLET CIRCULAR GROOVES LONGITUDINAL GROOVES TORSION BAR BALL SCREW LEFT TURN FIGURE 4 SCHEMATIC OF THE ROTARY VALVE OPERATION displacement is eliminated and the rotary valve returns toa neutral position Moderate effort at the steering wheel produces smaller valve displacements and lower power assist thus providing good steering feel At increased displacements the pressure rises more rapidly giving increased power assistance and quicker response Maximum pressure is developed after approximately 3 displacement giving a direct feel to the steering Groove displacement is limited by the freeplay of the stop spline mesh between the input shaft and ball screw The splines take up the steering movement while allowing the torsion bar to hold the groove displacement The torsion bar and stop splines form two parallel means of transmitting the steering torque When no steering torque is applied the torsion bar returns the valve grooves to a neutral position allowing the pressurized oil to flow to the return line Power assisted movement of the piston nut within its bore is limited by poppet valves installed in both piston faces When the piston approaches its extreme travel in either direction the stem of the limiting poppet valve makes contact at the end of the piston bore As piston travel continues the limiting poppet is
25. r The large porting of the valve design allows neutral position operating pressure to remain in the 40 65 psi range which results in reduced hydraulic pump power consumption and lower oil temperatures When steering effort is applied the input shaft and ball screw tend to turn in unison however the spring action of the torsion 3 BY PASS VALVE CIRCULAR GROOVES OIL IN ROTARY VALVE SUPPLY LN ei m OUTPUT SHAFT PISTON SEAL AND GLIDE RINGS FIGURE 2 bar results in the input shaft rotating slightly in advance of the ball screw The six pairs of grooves that form the rotary control valve are displaced from their neutral flow position As steering effort increases so does the amount of displacement Depending on the direction steered the groove displacement of the input shaft directs hydraulic oil through OIL INLET CONNECTING POLE MECHANICAL MOVEMENT PARTS MECHANICAL HYDRAULIC PARTS PARTS WITH NO MOVEMENT FIGURE 3 4 mm vgl H col Sf icee eens INPUT SHAFT OIL OUT Let L PW DELIVERY FROM ROTARY VALVE SPINDLE ASSEMBLY W ROTARY VALVE BALL SCREW ASSEMBLY OIL PASSAGE DRAIN PLUG the appropriate drilled passages in the ball screw to one side or the other of the piston Hydraulic pressure acting upon the piston surface eliminates much of the piston s resistance to movement Spring force exerted by the torsion bar causes the ball screw to rotate as piston resista
26. ressure of 1885 p s i 132 5Kg cm 41 947 in Ibs 474 m Kg Hydraulic ol Ford part no Ford Esp M2C1 38 CJ XT 2 QDX Dextron II Normal working temperature 0000111aaa 248 F 120 C Normal peak temperature 302 F 150 C Normal flow 4 2 2 GPM 16 1 L m Maximum working pressure 1885 60 psi 130 4Kg cm Maximum pressure drop in the return ducting H 60 psi 3 Kg cm IV PREVENTIVE MAINTENANCE POWER STEERING OIL Itis important that an approved oil be used to assure proper operation of the power steering unit The vehicle manufacturer s recommendations should be adhered to Once an oil type is in use it should never be mixed with any other type If it should become necessary to change types of oil the entire system must be drained following the procedure below DRAINING AND FILLING THE SYSTEM 1 Liftthe front axle sufficiently to raise the wheels clear of the ground 2 Disconnectthe return line at the valve body outlet port The outlet port is identified by the arrow which flows out of the gear Turn the steering wheel to the left as far as it will go Run the engine for 10 seconds at the most until the oil is drained from the reservoir and pump Switch off the engine and turn the steering wheel backwards and forwards from full lock to full lock until all the oil is drained out ROTARY VALVE LIMITING POPPET
27. s will facilitate the installation of the output shaft and allow the proper mesh between the sector and piston teeth See Figure 43 FIGURE 44 Install into the output shaft 35 the adjusting screw 36 the adjusting screw spacer 37 and the snap ring 38 Spacer 37 thickness is to be selected so that the axial play of the adjusting screw is between 0 and 0025 inch after the snap ring is installed See Figure 44 NOTE After selecting the proper spacer 37 thickness disassemble it grease the screw head with a lithium base general purpose grease Ford chassis grease ESA M1C75 B and reassemble screw spacer and snap ring PISTON OUTPUT SHAFT FIGURE 43 ADJUSTING SCREW WASHER 21 FIGURE 45 9 10 22 Install the side cover seal 39 on tool 297675 so that the seal s lip groove rests against the large diameter of the tool Insert the tool with the seal installed into the side cover and using a mallet drive the seal into place Install the o ring 40 in its groove on the side cover See Figure 45 Pack the output shaft roller bearings in the side cover and housing with a general purpose lithium base grease Ford Chassis grease ESA M1C75 B Lubricate the seals in the side cover and housing using a portion of the same grease Install the side cover 41 onto the output shaft 35 Turn the adjusting screw 36 counterclockwise with a 9mm socket until finger tight then back off an eighth of a
28. shaft is finely splined for connection to the steering column while the other end has a coarse spline which fits loosely with a similar spline inside the worm screw SPINDLE PITMAN ARM The coarse splines form mechanical stops which limit the amount of relative rotation between the ball screw and input shaft A torsion bar connects the input shaft to the ball screw Six evenly distributed longitudinal grooves are machined into the outer surface of the input shaft and correspond to six grooves machined into the bore of the ball screw Holes extend from the outside surface of the ball screw into the six grooves in the bore These holes allow pressurized oil to enter and exit the two inner elements of the rotary control valve The six grooves in the bore of the ball screw are connected alternately to each side of the piston through three pairs of the drilled holes The other three holes admit pressurized oil directly to three of the six grooves in the input shaft The other three grooves in the output shaft carry oil to the return line connection The length of the six pairs of grooves cut into the ball screw and input shaft allows large pressure changes to be achieved with a small rotational displacement of the valve elements The rotary control valve is an open center type which allows a continuous flow of oil through the longitudinal grooves in the input shaft and bore of the ball screw when held in the neutral position by the torsion ba
29. this procedure until the 4 18 inch pound increase in torque is noted NOTE A 19mm 12 point socket wrench can be used to rotate the input shaft When the adjustment is correct install lock nut 43 and apply a torque of 103 ft lbs with a 24mm torque wrench while holding the adjusting screw in position with the 9mm socket 12 After all the described steps have been performed check that the power steering unit runs smoothly throughout its entire motion and that the backlash at the center position is as prescribed in Step 11 above 13 Install the pitman arm 22 on the output shaft and secure it using washer 21 and nut 20 Torque nutto 370 410 ft Ibs 14 Install the gear on the vehicle and test for flow and pressure values shown in Section IIl of Technical Data X PRESSURE FLOW AND LEAKAGE TESTS PRELIMINARY 1 Connect Rotunda analyzer kit 14 0230 or equivalent to the power steering system as shown in Figure 49 Be sure shutoff valve is fully open 2 Put front wheels in straight ahead position transmission in neutral parking brake engaged 3 Start engine and partially close the pressure line shutoff valve until 800 1000 p s i is read at the pressure gauge When temperature of power steering fluid in the reservoir reaches 120 F fully open shutoff valve and turn engine off SYSTEM BACK PRESSURE CHECK 1 Insure shut off valve is fully open 2 Start engine and increase speed to 2200 r p m When fluid temperature
30. to allow installation of the snap ring 25 If the snap ring 25 cannot be installed remove the narrow bearing spacer and using tool 297647 drive the bearing race further into the housing Reinstall the narrow bearing spacer and install the snap ring 25 making certain it is completely seated in its groove Using tool 297647 tap the outer race from inside the housing 19 2 A FIGURE 41 20 until the bearing spacer and outer race are seated against the snap ring Install the seal 27 on tool 297674 so that the seal s lip groove rests against the large diameter of the tool Next install the thick bearing spacer on the tool making certain the flat side of the bearing spacer rests against the seal See Figures 41 E F amp G Insert the tool with the parts installed on it through the side cover opening and using a mallet drive the seal into place Install the boot retainer 24 in the housing Next install the small diameter of the boot 23 into the retainer making certain it is fully seated within the groove formed by the retainer HOUSING amp VALVE BODY ASSEMBLY 7 FIGURE 42 Insert the valve body spindle and piston assembly into the housing making certain not to damage the O ring seals Install the 4 bolts 1 and washers 2 that secure the valve body to the housing and tighten to a torque of 96 ft lbs with a 22mm torque wrench Turn the input shaft to center the piston teeth 48 in the side cover opening Thi
31. to the valve body PISTON ASSEMBLY 5 Refer to Figure 37 Install stop washer 56 limiting valve stem 54 limiting body 53 in the appropriate end of the piston 48 Apply a small amount of LOCTITE 222 on the threads of the limiting body nut 52 and install the nut in the piston Torque the nut to 17 foot pounds using the 6mm hollow hex wrench Tool 297660 and a 6 mm socket From the opposite end of the piston install one of the two ball valves 29 the spring 57 ball valve 29 stop washer 56 limiting valve stem 55 limiting body 53 Apply a small amount of locktite 222 on the threads of the limiting body nut 52 and install the nut in the piston Torque the nut 17 foot pounds using the 6mm hollow hex wrench and a 6mm socket 18 57 56 54 52 bel decl ff 29 53 FIGURE 37 NOTE The limiting valve stems 54 amp 55 must be installed in the same end of the piston as they were removed Reference Disassembly Step 10 When installing new stems 54855 the shorter stem must be installed facing the valve body housing side Install the ball screw by inserting it into the piston 48 See Figure 36 Insert the 19 balls 29 one by one in one of the openings for the recirculating tubes located in the piston 48 while turning the spindle at the same time Balls inserted in one opening should recirculate to the opposite opening as the ball screw is rotated Before proceeding make certain the balls are at an equal
32. turn See Figure 46 NOTE Be sure output shaft has contacted side cover prior to backing off an eighth turn FIGURE 46 Prior to inserting the output shaft into the housing wrap a single layer of masking tape around the splines and threads to protect the housing seal Lubricate the exterior of the tape with a lithium base grease Ford Chassis grease ESA M1C75 B and insert the shaft and side cover assembly into the housing with a twisting motion See Figure 47 FIGURE 47 FIGURE 48 Install the four washers 2 and the four bolts 42 that secure the side cover to the housing and torque to 96 ft lbs with a 22mm wrench See Figure 48 ADJUSTING THE PISTON SECTOR TOOTH BACKLASH 11 The piston and output shaft gear backlash is correct when a 4 to 18 inch pound increase in torque is noted as the input shaft is rotated and the piston passes through the mid point of its total travel in the housing The torque increase on the input shaft will occur only as the piston travels through the mid point of its travel and should disappear as the piston moves past the mid point To obtain the above adjustment rotate the input shaft 180 in both directions past the mid point of piston travel The mid point of piston travel is approximately one half the number of input shaft revolutions possible Each time the direction of input rotation is changed turn the output shaft adjustment screw 36 clockwise 1 8 to 1 4 turn Continue
33. wer steering housing or housing support loose B Excessive play between output shaft sector teeth and piston C Loose or worn ball studs in steering linkage Loose or worn intermediate steering shafts REMEDY Check oil level Check that there are no leaks bleed and top up with oil Check pump performance to specification Remove lines and clean Change piston seal rings Overhaul and test in accordance with vehicle service manual Inflate tires to correct pressure Disassemble and repair Replace ball screw assembly Check and if necessary replace seal rings 31 32 Replace ball screw assembly Overhaul and check in accordance with vehicle service manual Disassemble and repair Replace ball screw assembly Retighten mounting bolts Adjust gear lash If all adjustment has been used replace piston and output shaft Mechanical faults in vehicle steering members See vehicle manual SYMPTOM Power steering operates normally but is intermittently hard Oil leaks Power steering stiff when turning steering wheel quickly Power steering does not return correctly Power steering operates but with noise turbulence or vibration CAUSE Faulty operation of pressure pump Low oil level Dirty oil Faulty or incorrectly installed seal rings Hose or hose connections Faulty operation of hydraulic pump Restricted hose Incorrect hose size Front
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