GENERATOR GP 1640979 - Caterpillar

A. Steering Control Valve
The procedures for updating the steering control valve are in Special Instruction,"Steering/Brake Valve Modification - D9N (1JD1-2210), D10N (2YD1-1230) Track-Type Tractors", form SEHS9766.
B. Steering Control Valve
1. Remove the power train oil pump, separate the two pump groups and disassemble 7G2262 Pump Group.2. Rework 7G2256 Body Assembly (torque converter scavenge) by adding passage between two ports as shown in Illustration 1. Care should be taken when adding passage and installing hose fitting, as clearance to the sides of the pump body is minimal and breakout could occur.
3. Rework 7G2257 Body (transmission scavenge).a. Add passage as shown in Illustration 2. Care should be taken when adding passage and installing hose fitting, as clearance to the sides of the pump body is minimal and breakout could occur.
b. Add counterbore as shown in Illustration 2. Diameter should be sized to provide slight press fit with 1171261 Plate. 1171261 Plate outside diameter is nominal 53.38 0.05 mm.
c. Press 1171261 Plate into counterbore aligning two cutouts with bolt holes. Sealant or loctite is recommended in bottom of counterbore.4. Rework 7G2259 Cover Assembly.a. Add counterbore per Illustration 3.b. Press 5H4279 Plug into counterbore.5. Reassemble 7G2262 Pump Group, assemble pump groups together and install on tractor using new seals.C. Lube Manifold
1. Remove lube manifold from right front of the main case.2. Rework new 9G6595 Orifice by enlarging inside diameter to 22.2 0.05 mm. diameter.3. Remove old 9G6595 orifice from behind the main case manifold, and replace with reworked orifice.4. Additional rework may be required to obtain clearance between manifold mounting bolt head and 9U3398 Adapter. Refer to Illustration 9.5. Install manifold using new seals.D. Steering Clutch/Brake Module
1. Rework brake housing by enlarging two lube passage openings as shown in Illustration 4. A thin section (at o-ring inside diameter) may exist after machining. This thin section should be removed completely.
2. Rework retainer as follows: a. Clean up cast surface by machining as shown in Illustration 5.b. Install 1171262 Ring over 200 mm diameter (position three holes so that they do not intersect with any retainer holes), locate (with a center punch) three bolt holes and remove ring.c. Drill and tap three bolt holes per Illustration 5.d. Install 1171262 Ring and three 2D4534 Bolts.e. Enlarge lube hole passage starting from opposite end of retainer and continuing through 1171262 Ring as shown in Illustration 5.3. Rework center shaft as follows:a. Remove 0L1026 plug from entrance to longest (262 mm deep) lube passage.b. Enlarge longest (262 mm deep) lube passage per Illustration 6. Use of carbide tipped chucking reamer with added extension is recommended.
c. Enlarge openings (each end of above lube passage) per Illustration 6.d. Install new 0L1026 Plug at entrance to lube passage.4. Remove lube shuttle valve (6J7836 Ring, 6T7863 Sleeve, and 6T7862 Spool) and replace with a 1171263 Plug.5. Rework clutch hub by adding eight slots as shown in Illustration 7. Reference length should be measured first to determine end of slot dimensions. Radial positioning of the slots is not required - the first