7. Inspect each shift fork groove (B,
Figure 36
) for
wear or damage. Replace the gear(s) if necessary.
8. Inspect the bearing (B,
Figure 35
) in the middle
driven gear. It should turn smoothly without rough-
ness or binding.
9. Replace any washers that are worn.
10. Discard all snap rings and replace them during
assembly.
11. If any transmission parts are worn or damaged,
inspect the shift drum and shift forks as described in
this chapter.
MIDDLE DRIVE SHAFT ASSEMBLY
The following Yamaha special tools, or their
equivalents, are needed to remove and service the
middle drive shaft assembly. Have these tools on
hand before beginning this procedure.
1. Bearing retainer wrench (part No. YM-04137 or
90890-04137).
2. Middle gear backlash band (part No. YM-01231
or 90890-01231)
3. Damper spring compressor (part No. YM-33286
or 90890-04090).
4. Middle drive shaft holder (part No. YM-04055
or 90890-04055).
5. Middle drive shaft nut wrench (part No.
YM-045054 or 90890-04138).
Refer to
Figure 37
when servicing the middle
drive shaft assembly
Removal
1. Remove the engine, split the crankcase and dis-
assemble the cases as described in Chapter Five.
2. The bearing retainer was staked (
Figure 38
) dur-
ing assembly. Unstake it now.
3. Use the bearing retainer wrench (
Figure 39
) to
remove the bearing retainer (A,
Figure 40
) from the
left crankcase half.
4. Pull the middle drive shaft assembly (B,
Figure
40
) from the crankcase.
5. If necessary, disassemble the middle drive shaft
assembly as described in this section.
Installation
1. Install the middle driven shaft assembly if it was
removed.
TRANSMISSION, SHIFT MECHANISM AND MIDDLE GEAR
195
7
33
34
35
36