MR 332 - 06.2002 - EN
B1.49
PRIMARY SHAFT
60 05 029 93 - 10.2003 - EN
MR 332 - 06.2002 - EN
B1.50
Primary shaft
Fig. 1
B1-013
Step 7
General presentation
The primary shaft and its pinions form the upper line of the gearbox. The primary shaft supports the 1st, 2nd, 3rd
and 4th gear driven pinions. The rear teeth is in constant mesh with the Turtle pinion. The shaft front is supported
by the tapered bearing at the rear of the input housing and by the bearing fitted in the housing rear bearing
assembly.
The 1st and 4th gear pinions are maintained in position by 2 spacers. The axial clearance of the pinions is achieved
by the fitting of the shims between the 1st and 2nd gear pinions.
Removal/installation of the primary shaft
Preliminary operations
To properly shim the bearings when replacing the primary shaft, it is required to remove the gearbox.
60 05 029 93 - 10.2003 - EN
MR 332 - 06.2002 - EN
B1.51
Primary shaft
Fig. 2
B1-079
Description
(1) Needle bearing
(2) Primary shaft
(3)
Inner cage bearing
(4) Cup bearing
(5) Shims
(6) Deflector
(7) 3rd gear pinion
(8) Spacer
(9) 4th gear pinion
(10) Spacer
(11) 1stgear pinion
(12) Shims
(13) 2nd gear pinion
(14) Circlip
(15) Inner cage bearing
(16) Cup bearing
60 05 029 93 - 10.2003 - EN
MR 332 - 06.2002 - EN
B1.52
Primary shaft
Removal
- Remove the deflector, the shims and the cup. Extract
the assembled shaft (Fig. 3).
- Extract the bearing cones.
Note: couple the cones and the cups in case of
reuse.
- Remove the circlip.
- Remove the 2nd gear pinion, the shims, the 1st gear
pinion and the spacer.
- Remove the 4th and 3rdgear pinion.
- Extract the needle bearing and discard it.
Installation
- Clean and inspect the parts, replace all faulty parts.
- Fit the needle bearing in contact on the shaft
shoulder using a press.
Note: after fitting, make sure that the needle
normaly turn in the cage.
- Install the 3rd gear pinion and the 4th gear pinion.
- Slide the spacer. Fit the 1st gear pinion and the 2nd
gear pinion.
- Fit the circlip
- Using a set of feeler gauges, meas