Disassembly
Transmission
Disassembly
Exploded View Of ZF S5-42 Manual Transmission (Part 1 Of 2):
1. Attach the transmission to the Bench Mounted Holding Fixture T57L-500-B or equivalent. Place transmission in a vertical position with the front case pointing downward.
2. Using a suitable chisel, bend tab back on output flange retaining nut.
Removing Output Flange To Mainshaft Attaching Nut:
3. Attach companion flange holding tool No. T87P-4851-A or equivalent to transmission output flange, then loosen output flange to mainshaft hex nut.
NOTE: Do not remove hex nut or output shaft flange.
4. Remove 15 of the 17, 8mm hex head front and rear case retaining screws. Leave 2 screws at opposite ends of case installed.
5. Remove any power take-off equipment installed on transmission.
Removing Shift Tower:
6. Remove eight 8mm shift tower assembly-to-front case attaching bolts, then the gearshift lever and tower as an assembly.
7. Remove interlock plate and compression spring which serves as a reverse gear interlock.
CAUTION: Use care to ensure parts do not fall into transmission.
8. Place a suitable drift against the detent bolt sealing cap, then hold drift at an angle. Position point of drift off center of cap, then drive cap inward until spring pressure against underside of cap forces cap out of hole.
NOTE: Repeat this procedure for the other two detent bolt sealing caps in front case. Discard removed caps and replace with new sealing caps.
WARNING: cap is under spring pressure. always wear protective eyeglasses when performing this procedure to ensure that cap does not strike eyes when it is forced out by spring pressure.
9. Remove springs protruding from sealing cap holes, then drive out sealing caps for two reverse idler shaft cap screws. Remove reverse idler shaft cap screws.
10. If required, remove back-up lamp switch, then the back-up lamp switch sealing ring.
11. Use a suitable punch to remove two dowel pins from the two upper corners of rear case to front case mating surfaces. Drive pins toward rear of the transmission case.
12. Remove two remaining hex bolts from rear case.
13. Carefully lift front case from rear case. It may be necessary to push central shift rail inward to prevent it from "hanging up" on front case as it is being removed. Use care to ensure central shift rail is not lifted with front case. Refer to Subassemblies in this section for Front Case disassembly and assembly.
CAUTION: The mating surfaces of two housing assemblies are coated with an adhesive sealing agent. If it is difficult to separate the two housings because of this adhesive, carefully tap the front of the front case with a soft hammer. Refer to Subassemblies in this Section for Front Case disassembly and assembly procedures.
14. Remove central shift rail and shift finger assembly.
15. Lift the shaft out of the reverse idler gear, and remove the gear and two caged roller bearings from rear case.
16. Remove the three capscrews that retain shift interlock to rear case.
Installing Lifting Sling:
17. Position transmission vertically on stand, then use nylon lifting sling D87L-1000-A or equivalent to strap gearpack holding fixture tool T87T-7025-HH or equivalent to mainshaft and output assemblies. Pass sling over shift rails.
18. Place shift rod support tool No. T87T-7025-JH or equivalent over ends of shift rails.
19. Carefully rotate transmission, together with gearpack holding fixture, into a horizontal position with holding fixture beneath gearpack.
20. Remove output shaft flange retaining nut from output shaft, then remove flange from output shaft, tapping with a soft hammer if necessary.
21. Carefully pull gearpack and shift rails with holding fixtures forward and dislodge from rear case.
22. If equipped, remove speedometer drive gear from mainshaft.
23. Remove sling from shift rails, gearpack and holding fixture, then rotate gearshift rails approximately 45° and release from shift hubs. Lift gearshift rails, forks and interlock with support tool from transmission.
24. Using the shift rod support as a base, set the shift rail assembly on a workbench with the shift rails in a vertical position. Remove the interlock.
25. Mark each shift fork, shift rail and position in the holding fixture to make reassembly easier. Lift shift rails from support tool.
26. Lift countershaft off the bench stand. Separate input shaft from mainshaft.
27. Lift mainshaft from the stand. Refer to Subassemblies in this section for mainshaft, countershaft and input shaft disassembly and assembly procedures. Remove rear cover from holding fixture. refer to subassemblies in this section for rear case disassembly and assembly procedures.