Mainshaft: Service and Repair

Mainshaft Assembly:

1. Remove bearing from 4th gear end of mainshaft, then label for installation.
2. Remove 4th gear and synchronizer blocker ring.
3. Remove 3rd-4th synchronizer retaining ring. Remove 3rd and 4th gear synchronizer assembly, blocker ring and 3rd gear from mainshaft.
4. Remove 2nd and 3rd thrust washer retaining ring, then the two-piece 2nd-3rd gear thrust washer.
5. Remove 2nd gear and blocker ring. Then remove the 1st-2nd synchronizer retaining ring.
6. Remove 1st-2nd synchronizer assembly, blocking ring and 1st gear from mainshaft.
7. If damaged, remove tapered roller bearing from the pinion end of the mainshaft, using pinion bearing cone remover, tool No. D79L-4621-A or equivalent and an arbor press.
8. Reverse procedure to assemble and note the following:
a. Oil all parts and gear bores with transmission fluid.

Aligning Gear & Synchronizer Hub:

b. When assembling synchronizers, index marks must be aligned.

Installing Synchronizer Sleeve:

c. Tab on synchronizer spring is installed into groove of insert, then snapped into place. Tab of second spring is installed into same insert on opposite side of synchronizer assembly then rotated in opposite direction and snapped into place.

Synchronizer Assembly:

d. When assembling synchronizers, sleeves and hubs must be held squarely to prevent jamming.