Disassembly and assembly of the secondary shaft (Audi 100 C3)

Disassembly

Press the inner race of the rear tapered roller bearing together with the 1st gear sliding gear.



Remove the 1st gear needle bearing and the 1st gear synchronizer locking ring.

Remove the 1st and 2nd gear synchronizer retaining ring.

Press the sliding clutch assembly together with the hub and the synchronizer locking ring and the 2nd gear sliding gear.

Remove the first circlip of the 3rd gear.

Press out the third gear using a press.



Remove the second 3rd gear retaining ring.

Remove the 4th gear retaining ring.



Press off the 4th gear pinion using a Kukko 17/2 type puller.



Press off the inner race of the front tapered roller bearing using a puller.

Assembly

Press the front tapered roller bearing inner race onto the shaft.

Heat it up, then use a press to press the fourth gear onto the shaft with the flange towards the third gear.



Adjust the axial clearance of the fourth gear pinion. To do this, slide the cooled fourth gear pinion onto the shaft until it stops, then select the most suitable retaining ring in thickness and install it in place. The axial clearance should not exceed 0.02 mm.







Install the second 2.40 mm thick snap ring of the 3rd gear.

Heat it up, then use a press to press the third gear onto the shaft until it stops, with the flange facing the sliding second gear.

Install the first snap ring.

Measure the axial clearance of the third gear pinion with a feeler gauge, which should be within 0.00-0.04 mm. By selecting a retaining ring of the appropriate thickness, achieve the smallest clearance.



Lubricate with hypoid oil and install the 2nd gear needle bearing.

Check the wear of the 2nd gear synchronizer locking ring. To do this, push the ring all the way toward the cone of the 2nd gear sliding gear and use a feeler gauge to measure the axial clearance between the end of the locking ring and the end of the gear ring of the synchronizer gear, which should be at least 0.5 mm (see photo).



Install the 2nd gear sliding gear.

If the sliding sleeve has been disconnected from the hub, slide the sliding sleeve onto the hub, install the crackers into the hub grooves and install the springs with the connectors at an angle of 120° relative to each other. The bent ends must be placed behind the cracker projections.

Press the hub assembly with the clutch onto the shaft so that the reverse gear teeth are directed towards the 2nd gear gear. Turn the 2nd gear synchronizer locking ring so that the ends of the crackers enter the grooves of the ring.

Install the retaining ring.

Measure the synchronizer axial clearance with a feeler gauge, which should be within 0.00-0.04 mm. Achieve the smallest possible clearance by selecting a retaining ring of the appropriate thickness.

Check the wear of the 1st gear synchronizer locking ring in the same way as for the 2nd gear synchronizer locking ring.

Note: Please note that the synchronizer locking rings for 1st and 2nd gears are not the same. The synchronizer locking ring for 1st gear has three fewer teeth with a taper angle of 110°. The synchronizer locking ring for 2nd gear has a full set of teeth and a taper angle of 115°.

Lubricate with hypoid oil and install the 1st gear needle bearing.

Install the 1st gear sliding gear.

Using a press, press the inner race of the rear tapered roller bearing until it stops.

Measure the axial clearance of the 1st gear sliding gear with a feeler gauge; it should be within 0.10–0.40 mm.





If there is any deviation from the norm, check the adjustment of the axial clearance of the synchronizer of the 1st and 2nd gears.