Shifter Forks

NOTE:

The disassembly and assembly procedure is the same for early and late style transmissions. However, on late 1979 and later transmissions, the shifter fork assemblies are reversed on the shifter shaft, that is, the side with the nuts (5) face the center of the shaft. See Figure 4-16.

REMOVING SHIFTER FORKS (Figure 4-16)

Remove shifter cover and transmission side cover as described in "Removing Shifter Cover."

Shifter fork shaft (2) is held in position by lock ring (1). With lock ring (1) removed, shaft may be driven out by means of a drift inserted in hole in starter cover joint face transmission case. Notice that a rubber oil seal (3) is assembled in groove next to lock ring.

Mainshaft and countershaft shifter fork assemblies are not interchangeable. Note exactly the arrangement of parts and components in each. Keep parts separate to avoid needless adjusting when reassembling. If inspection shows fork assemblies are not damaged, worn or bent, it may not be necessary to disassemble them unless shifter clutches are replaced. Adjustments are described in "Assembling Shifter Forks."

If it is necessary to disassemble shifter forks, lift off shifter finger rollers (4), pry back ear on lockwasher (6) and turn off nut (5). Lift shifter fork (7, 8) and variable number of spacing shims (9) off shifter finger (10).

CLEANING, INSPECTION AND REPAIR

Clean all parts in cleaning solvent and blow dry with compressed air.

If shifter forks are bent or worn, replace them. Straightened forks are weak. They may break and cause extensive damage to transmission parts.

Check fit of shifter fingers on shaft. If they are loose enough to give fork action lash, replace them. Check replacement part fit on shaft.

Lap out shifter fingers if they bind. Shifting will be difficult unless fingers work freely on shaft.

ASSEMBLING SHIFTER FORKS

Assemble shifter forks in reverse of disassembly order making sure parts are not transposed. Tighten nuts (5) to 25 ft-lbs torque.

Bend top tab of lockwasher down against flat on nut so lockwasher tab does not interfere with shifter cam.

Place shifter forks in transmission case and install shifter fork shaft. Fork with narrow opening is for high gear shifter clutch.

^^^ Late 1979 to 1980 1978 to early 1979

1978 to

Late 1979 to 1980

Late 1979 to 1980

1978 to

Lock ring Shifter fork shaft Oil seal

Shifter finger rollers Nut (2) Lockwasher (2) Shifter fork (mainshaft) Shifter fork (countershaft) Spacing shim (variable number) (0.007 in. and 0.014 in.) Shifter finger (2)

Figure 4-16. Shifter Fork - Exploded View

SETTING GAUGE — EARLY 1979 AND EARLIER

With shifter cam in neutral, check adjustment of shifter forks with Fork Shifter Gauge, Part No. 96384-39, by placing shifter gauge on shifter cover as shown in Figure 4-17. With the 3/8 in. gauge rod furnished, set tool gauge block in exact alignment with straight section of one cam slot in shifter cam. Lock gauge block in place with thumb screw. Rotate shifter cam and repeat for other cam slot.

Remove tool from cover, turn it over, and place it on transmission case with shifter fingers engaged in slots on gauge blocks as shown in figure 4-18. Be sure shitter tinger rollers are in place on shifter fingers.

SETTING GAUGE — LATE 1979 AND LATER

See Figures 4-18A and 4-18B. With shifter cam In neutral, check adjustment of shifter forks with Fork Shifter Gauge, Part No. 96385-78 as follows:

Place tool on cover, adjusting sliding blocks of tool so that the hubs enter cam slots in shifter plate. Tighten lock screws.

See Figure 4-18C. Remove tool from cover, turn it over, and place it on the transmission case with shifter fingers engaged in slots of sliding blocks. With suitable thickness gauges, check the clearance of shifting members.

Remove tool from cover, turn it over, and place it on transmission case with shifter fingers engaged in slots on

Figure 4-17. Adjusting Shifter Gauge — Early 1979 and Earlier

Figure 4-18A. Shifter Cam in Neutral Position — Late 1979 and Later

Figure 4-17. Adjusting Shifter Gauge — Early 1979 and Earlier

Np435 Shift Fork Neutral

Figure 4-18A. Shifter Cam in Neutral Position — Late 1979 and Later

Figure 4-18. Checking Shifter Clutch Clearance — Early Figure 4-18B. Adjusting Shifter Gauge

1979 and Earlier — Late 1979 and Later

Figure 4-18C. Check Shifter Clutch Clearance — Late 1979 and Later

CHECKING FORK ADJUSTMENT

With thickness gauges, check clearance on both sides of shifting clutches. All shifting clutches must be centered.

Clearances between shifter clutch and gear for all models are as follows:

Countershaft low and second gear: When centered between gears to have 0.080 to 0.090 in. clearance on both sides.

Mainshaft third and high gear: When centered between gears to have 0.100 to 0.110 in. clearance on both sides.

Where shifter clutch engagement is with dogs protruding from face of gear, turn gear so dogs on shifter clutch and dogs on gear are overlapping each other about 1/8 in. before checking clearance.

When clearances are not equal and correct, fork assemblies must be corrected by increasing or decreasing the number of shims between shifter fork and shifter finger. To make this adjustment, remove shifter fork assemblies from transmission. Shims are available in 0.007" and 0.014" thick.

After taking out or adding shims, be sure fork assembly locknut is tightened to 25 ft-lbs torque. Excessive tightening may close up shifter finger so it is no longer a free sliding fit on shaft. Bend top tab on lockwasher down against flats on nut so lockwasher tab does not interfere with shifter cam.

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