Hydrostatic Transmission Service & Testing 544, 656, 70, 86 & 666 Tractors

International Harvester Service Manual Hydrostatic Transmission Service & Testing 544, 656, 70, 86 & 666 Tractors Service Manual THIS IS A MANUAL PRODUCED BY JENSALES INC. WITHOUT THE AUTHORIZATION OF INTERNATIONAL HARVESTER OR IT S SUCCESSORS. INTERNATIONAL HARVESTER AND IT S SUCCESSORS ARE NOT RESPONSIBLE FOR THE QUALITY OR ACCURACY OF THIS MANUAL. TRADE MARKS AND TRADE NAMES CONTAINED AND USED HEREIN ARE THOSE OF OTHERS, AND ARE USED HERE IN A DESCRIPTIVE SENSE TO REFER TO THE PRODUCTS OF OTHERS. IH-S-HYDRO TRN

INTERNATIONAL HARVESTER SERVICE MANUAL HYDROSTATIC TRANSMISSION SERVICE & TESTING 544, 656, 70, 86, 666 TRACTORS

Special Service Tools Required..... Standard Torque Data for Nuts and Bolts Specifications......... Speed Ratio Charts... CONTENTS Principles of Hydrostatics General.... How It Works.... Variable Displacement Pump and Variable Displacement Motor.. Servo Cylinders........ Center Section.... Operating Principles Hand Controlled Models................. Neutral.. Forward (Tractor Moving Forward). Reverse (Tractor Moving Rearward) Forward (Tractor Decelerating) Foot Controlled Models... Neutral................... Forward.. Reverse..... Forward (Tractor Decelerating) Familiarization and Component Identification..... Controlling the Tractor (Hand Controlled Models) High-Low Range Selector.... Speed-Ratio Control...... Foot-N-Inch Valve and Drive Control Valve.... Foot-N -Inch Valve.. Drive Control Valve. Controlling the Tractor (Foot Controlled Models) General.... Dump Valve.... Two Position Deceleration Valve........ Controls........ Unit Service Hydrostatic Transmission.. Removal......... Disassembly.... Cleaning Inspection and Repair.. Reassembly..... Flex Plate Installation......... Clean Up of Entire Hydraulic System and Power Train. Servicing Components Servo Cylinders.... Removal. Disassembly. Inspection. Reassembly.... Page 5 6 7 9 10 12 12 14 15 16 16 16 17 17 18 18 18 19 19 20 24 24 25 26 26 27 27 27 28 30 30 32 42 46 60 61 63 63 63 64 64 3

Page Charge and Servo Pump........ Servo Relief Valve Improvements Removal Disassembly... Inspection...... Reassembly.... Center Section Components Check Valves, High Pressure Relief Valves and Shuttle Valve Importance of Proper Torque on High Pressure Relief Valves Replacing Relief Valves... Replacing Check Valves ReRlacing Shuttle Valve Multiple Valve Body... Drive Control Valve... Removal (F-Models) Removal (I-Models) Service Foot-N-Inch Valve.... Range Transmission and MPH Drive.. Hydraulic and Differential Lubrication Circuits Adjustments Hand Controlled Models Neutral Adjustment for Servo Control and Linkage Foot-N-Inch Valve... Drive Control Valve... Safety Start Switch (F - Models) Safety Start Switch (I-Models) Foot Controlled Models..... Adjusting for Neutral Pedal Adjustments... Dump Valve and Safety Starting Switch Two Position Deceleration Valve. Testing and Trouble Shooting General Information...... Importance of Excluding Air.. Eymptoms of an Aerated System. Step by Step Check for Causes of Air Leaks Checkmg Pressures and Charge Pump Flow.. General.... Method of Checking Drive Pressure Charge Pump Pressure and Flow Charge Pump Flow Used in Trouble Shooting Servo Pump Pressure.. Deceleration Pressure (Hand Control). Testing Other Components.... Checking Time Delay of Anti -Coast Valve Drive Control Valve... Drive Control and Foot-N -Inch Valve Checking by Elimination Trouble Shooting............................... General Inforn1ation. Safety Starting Procedure. 64 64 65 66 66 66 68 68 68 68 69 70 70 72 72 72 72 73 74 75 76 76 77 77 79 79 79 79 80 81 82 83 83 83 84 86 86 86 87 89 93 93 94 94 95 96 97 100 101 4

The movement in degrees of the pump and HlOtor swash plates is as follows: The angle of the pump swash plate is varied from 0 degrees to 16 degrees both in Forward and Reverse. The angle of the motor swash plate is varied from 18 degrees to 8 degrees in both forward and reverse. This difference between the foot control models and the hand control models is accomplished by using different cam control slots and different swash plates. The stops on the swash plates are ground to different angles. The size of the pump variable orifice button is also smaller on the foot control models. UNIT SERVICE Hydrostatic Transmission Removal 1. Make a front end split, as shown 1D Illust. 16. NOTE: It is necessary to remove the starter as one of the bolts is in the bell housing behind the starter motor. IIlust. 16. Front section split (F-656J. 30

IIlust. 17. Removing the fuel tank and steering support (F 656). 2. Remove the fuel tank and steering support referring to Illust. 1 7. The following components must be disconnected: a. The miles-per-hour cable must be unhooked behind the instrument panel and threaded down behind the fuel tank to be freed up. b. Batteries removed as required. c. The rear platform. d. Shift linkage. e. The line from the Drive Control valve to the tee on the transmission housing cover. f. Remote control hydraulic lines at the rear. g. The two pres sure lines for the auxiliary valves and draft control valves disconnected at the pump flange. h. Dis c onne ct electrical wire s as necessary. 31

NOTE: To check the plate for wear, run your finger nail or a sharp pencil acros s the face of the plate. If wear is felt, replace the plate. Minor scratches and burns may be lapped out by using lapping stone FES 123-2. 20. Inspect the ball guide for excessive heat indication or severe scratches. A slight discoloration is normal. 18. Thoroughly clean the bearing plate in clean diesel fuel and oil liberally with Hy-Tran. Illust.67. Motor parts damoged by towing or high speed coasting. Score marks FESM-2644 II lust. 65. Motor bearing plate scored from contaminated oil, use of oil other than Hy-tran, or poor lubrication from loss of charqe pressure. NOTE: Illust. 67 shows a ball guide damaged by towing. With no charge pressure the slippers may lift off of the thrust plate, damage the slipper retainer and ball guide. See also Illusts. 63 and 65. 21. Inspect the slipper retainer for damage. A slight wear pattern where the slippers ride is normal. Replace if wear is exces sive or not perfectly flat. Illust.66. Motor bearing plote in good condition. 19. Inspect the bearing plate for scratches, excessive wear or erosion (Illusts. 65 and 66). A worn or scored bearing plate reduces pump efficiency. A valve plate and bearing plate must be replaced as a set. Illust.68. Thrust plate inspection. 22. Inspect the thrust plates (for the swashplates) for wear, embedded material, or scoring (Illust. 68). 45

28A. Install the high pressure tubes. NOTE: Do not over tighten or fittings can be damaged. 31. Loosely connect up the recirculating line between the multiple valve body and elbow coming out of the left side of the housing. 29. Using new O-rings, install the elbow fitting and the short jumper tube for the recharging line into the upper end of the suction manifold and secure it with the jam nut. 32. Install the two cast spacers and multiple valve body with fittings and valves installed, being careful to work the spacer plate over the O-rings on the jumper tubes. /' External check port, --Servo relief valve O-ring ---i-i~cj! Port to -...;.::+-~ servos Seal ring Pump body FESM 2489 Port to spray lube for pump slippers IIlust. 102. Correct bolt lengths for multi-valve and top covers. IIlust. 101. Servo relief valve with new screen and external test port. 30. Install the servo relief valve with both screens. Tighten the servo supply tube and install cover. Install the other vertical jumper tube in center section with new O-rings on both ends. See Illust. 101 and see page 64 "Servo relief valve improvements" for details of latest remote check port. IMPORTANT: See Illust. 102 for installation of bolts. Installing the bolts incorrectly can result in pulling threads out of the housing. Tighten the recirculating line. 33. Tighten the cente r section R. H. j unction block plug to 50 ft. Ibs. and bend the clip to clamp the servo supply tube. 57

Checking Pressures and Charge Pump Flow General 1. Warm oil up to 135 degrees. 2. Have rear wheels off the ground so motor can rotate while checking. 3. Use only approved tubing and fittings - pressures are developed up to 5800 psi. 4. Drive pressure will depend on the load applied. Brakes must hold if they are used to apply the load. 5. All 544 and 656 models have the same drive pressures. 6. The same principles apply in reverse except that it is harder to stall the tractor with the brakes. The brakes do not hold as well in reverse as the motor swash plate stays at the maximum angle in reverse. You may not be able to reach relief valve pressure if the brakes are not holding well. Illust. 144. Checking forward and reverse drive pressure, 1-544 and 1-656 (hand control). 7. Drive pressure only, does not indicate efficiency (see checking charge flow below). Method of Checking Drive Pressure With Gauges Illust. 145. Checking forward and reverse drive pressure, 1-544 and 1-656 (foot control). 1. Install FES 123-2 gauge as shown for the specific tractor below. See Illusts. 143, 144 and 145. Illust. 143. Checking forward and reverse drive pressure, F-544 and F-656. IMPORTANT: Allow the tractor to creep. The motor must rotate (wheels moving) for accurate checks. 86

FOREWORD The instructions and special tools shown in this Blue Ribbon Service Manual are for use by International Harvester Dealers and their factory trained servicemen. The specifications as listed in this manual are current as of the printing date. Due to changes and improvements in our products, dealers are periodically issued service bulletins to keep this manual up-to-date. We suggest you refer to the most recent information when performing service work on this equipment. International Harvester Factory Trained servicemen are best qualified to service IH equipment. GSS-1405 (W/Revision 1) TESTING AND TROUBLE SHOOTING Hydrostatic Drive 544 and 656 Series Tractors IMPORTANT All Specifications and Service Procedures for the 656 also apply to the Model 70,86 and 666 Hydrostatic Tractors.

Introduction...... CONTENTS Do's and Don'ts of Hydrostatic Tractor Servicing....... Tools Required for Field and Shop Service Kit for Servicing 656 & 544 Series and 3514 & 3616 Hydrostatic Tractors Tools Required for Checking Charge Flow and Running Clean-Up Procedure.. Tools Required to Check all Pressures at the Same Time, and for Isolating Drive Control and Foot-N-Inch Valves.... Tools Required for ServiCing Check Valves, Relief Valves and Servo Cylinders.... Miscellaneous Tools and Supplies.... Basic Explanation of Each System Component and Possible Malfunctions High-Low Range Transmission....... S-R Lever and Effects of Poor S-R Lever Adjustment....... Center Section Shuttle Valve and Possible Malfunctions........ High Pressure Relief Valves................ Parts Which Can Cause High Pressure Valves to Open.......... Drive Control Valve............. Foot-N-Inch Valve..................... Servo Cylinders (How They Operate)........... Servo Cylinders (Possible Malfunctions).......... Pu.mp Servo........................................... Motor Servo.............. Step-By Step Checks During Trouble Shooting Step-By-Step Check Outline........... General.... Checking Statically.............................................. Test Driving............. Checking Anti-Coast Valve.......... Checking Reverse Deceleration..................................... other Possible Malfunctions Which May Show Up During Driving Test.......... Checking for Speed of Servo Response.... Further Checks After Test Driving................................ Pin Pointing the Cause for "Slipping"............... Checking Charge Pressure................... Checking Servo Pressure.... Checking Drive Pressure (With Gauges).... Checking Drive Pressure (Without Gauges).... Foot-N-Inch Valve.... Isolating the Drive Control Valve..... Checking Charge Flow............................... Flushing the Flo-Rater................................... Driving Procedure for Checking Flow.... Checking Charge Flow on Tractors Equipped with Recirculating Filter Parts Accessory No. 530976 R91... Clean-Up Procedure After Major Overhaul.. Clean-Up Procedure for Tractors with Recirculating Filter Installing Recirculating Filter. Checking Complaints of High Fuel Consumption or High Temperatures. 35 Parts Which Can Be Removed Without Splitting the Tractor 35 Page 4 5 6 7 8 8 9 9 10 10 11 11 12 12 13 13 14 16 16 17 18 20 20 20 21 21 21 22 23 23 26 27 27 28 28 31 32 33 33 34 3

I NTRODUCTI ON Inasmuch as the hydrostatic drive tractors are new and most servicemen have had a limited amount of experience with them, a very complete service Manual GSS-1397 has been prepared. In GSS-1397, full explanations are given for the function of each component including removal and servicing of every component. It should be studied thoroughly and must be completely understood before troubleshooting can become easy for serviceman. This trouble shooting and testingmanual is not intended to replace GSS-1397 and both should be used while making field service calls. The handbook contains some new information not in GSS-1397 but is mainly intended as a condensed quick reference book. Most problems encountered on the tractor are of a minor nature and can be pinpointed quickly and fixed easily once the system is fully understood. IN ORDER TO MAKE THE MOST EFFICIENT USE OF TIME WHEN MAKING FIE LD SERVICE CALLS, SERVICEMEN SHOULD MAKE UP A "HYDROSTATIC FIELD SERVICE KIT" WHICH CONTAINS THE FEW SPECIAL SERVICE TOOLS NEEDED AND PARTS AND SUPPLIES REQUIRED. MANY PROBLEMS CAN BE FIXED DURING THE FIRST CALL IF THIS KIT ACCOMPANIES THE SERVICEMAN. 4