Synchronizers and Synchronizer Rings

All synchronizer components are available as replacement parts. All synchronizers except the 3rd/4th gear synchronizer are removed and installed as part of the transmission disassembly procedure. Remove and install 3rd gear and the 3rd/ 4th gear synchronizer as shown in Fig. 7-20 and Fig. 7-21.

Fig. 7-20.

3rd gear and 3rd/4th gear synchronizer being pressed off of main shaft. Remove circlip and press off together.

Fig. 7-21.

3rd gear and 3rd/4th gear synchronizer being pressed onto main shaft. Turn synchronizer ring until grooves are in line with synchronizer keys.

Check the wear of the synchronizer rings and their gears as shown in Fig. 7-22. Table d gives wear specifications.

Fig. 7-22.

Checking wear of synchronizer ring and gear Measure gap a with feeler gauge. Table d gives specifications and wear limits.

Table d. Synchronizer Ring Wear Specifications

When assembling synchronizers, install the retaining springs as shown in Fig. 7-23, Fig. 7-24, Fig. 7-25, and Fig. 7-26 show identification and assembly of the different synchronizers.

Fig. 7-23.

Installed position of synchronizer retaining springs (dotted line). Springs are on both sides of synchronizer. Angled spring ends must engage keys. Install so springs are offset by 120°.

Fig. 7-24.

1st/2nd gear synchronizer. Top: 1st gear synchronizer ring identified by missing teeth (arrow). Bottom: When assembling, groove on hub should face 1st gear. Groove may be on front face (black arrow) or on splines (white arrow).

Fig. 7-25.

3rd/4th gear synchronizer. Top: Synchronizer hub identified by groove on 4th gear side (white arrow) or on splines (black arrow). Bottom: When assembling, chamfer on hub inner splines (black arrow) faces 3rd gear, groove at outer splines (white arrow) faces 4th gear.

Fig. 7-26.

5th gear synchronizer.