Main casing of manual transmission — disassembly and assembly (Opel Omega A)

1. Unscrew the bolt near the hole of the gear shift lever shaft retainer, then remove the reverse gear block, spring and shaft from inside the housing (photo).







2. If necessary, remove the radial bearing of the gearshift lever shaft using a suitable extractor (photo).



3. Use pliers to remove the retaining ring of the roller bearing of the positioning mechanism (photo). If it is jammed, lightly hit the bearing inward. Remove the linings and knock out the bearing from the inside with a metal tube.







4. Using a metal tube, knock out the input shaft bearing from inside the housing (photo).



5. Clean all components and replace as necessary.

6. If the main housing or positioner is replaced, perform the following procedure to locate the positioner roller bearing spacer.

7. Place the rear case on the bench, install the positioning mechanism in it with the 5th gear facing up.



8. Temporarily install the roller bearing without the positioner linings into the main housing. With the snap ring in position, tap the bearing outward until it contacts the snap ring.

9. Place the main cover on the rear crankcase, insert the bolts shown in Figure 6.8. Tighten them to a torque of 25 Nm.

10. Install a test indicator on the 5th gear pinion of the positioning mechanism (photo). Set the indicator to zero.



11. Insert a screwdriver through the hole under the oil drain plug, move the positioning mechanism up (photo). Record the indicator readings (lateral play), then subtract 0.20 mm from it to determine the shim thickness required for the roller bearing of the positioning mechanism. The side play should be 0.15-0.25 mm, shims are available in thicknesses of 1.7, 1.8, 2.0, 2.1 and 2.2 mm.



12. Remove the positioning mechanism.



13. Install the positioner roller bearing to the main housing with the shims (photo). With the snap ring in position, tap the bearing outward until it contacts the shim.



14. Hammer the new gearshift shaft bearing into the housing (photo).



15. Install the reverse gear assembly, shaft and spring, making sure the short end of the spring is in the housing and the long end on the assembly. Insert and tighten the bolt.

16. The input shaft bearing is not installed at this stage.