GMC T Series 1994 Repair Manual page 827

Figure 20— Removing the Main Drive Gear Bearing
2. Magnetic disk at the bottom of the transmission
case.
Inspect
1. Case for cracks.
2. Front and rear faces of the transmission case for
burrs, and if present, dress them off with a fine mill
file.
BEARING ROLLERS AND SPACERS
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Inspect
• Drive gear bearing rollers for chips, cracks, or
excessive wear and replace if necessary.
• Reverse idler shaft for wear and damage.
• Spacers for wear.
FRONT AND REAR BEARINGS
|*]|y| Clean
1. Front and rear bearings thoroughly with appropriate
solvent.
2. Blow out bearings with compressed air.
• Do not allow the bearings to spin. Turn them
slowly by hand. Spinning bearings may damage
the race and rollers.
3. Lubricate bearings with Dexron® HE or equivalent
transmission fluid.
Inspect
L *
Bearings for roughness by slowly turning race by
hand.
SYNCHRONIZER BLOCKER RINGS
The first-second synchronizer outer cone and the
third-fourth blocker ring are lined with friction material
and cannot be checked visually for wear. Replacement
is necessary when the gap between blocker teeth and
adjacent clutch teeth is significantly less than specified.
Fifth gear blocker ring is brass and can be checked
visually for wear and damage.
Important
Make certain the blocker rings are correctly
identified before assembly. The first-second
synchronizer blocker ring does not have friction
material. The third-fourth synchronizer blocker
ring has friction material. Assembling one in
place of the other will result in serious damage
to the transmission.
I? Inspect
• Fifth-gear blocker ring for wear and damage.
Third-Forth Blocker Rings
Assemble (Figures 21 and 22)
❖
1. Third-gear blocker ring (31) to third gear (35) with
twisting motion to fully seat.
2. Fourth-gear blocker ring (31) to drive gear (100)
with twisting motion to fully seat.
Measure
• Gap between vertical faces of blocker teeth and
clutch teeth. Nominal gap is 0.88 - 1.50 mm (0.035
- 0.059 inch) for new blocker rings.
First-Second Blocker Rings
* Assemble (Figures 21 and 23)
1. Three-piece first-gear blocker ring assembly using
a twisting motion to fully seat.
2. Three-piece first-gear blocker ring assembly with
needle bearing (21) and bearing sleeve (20) to first
gear (22).
3. Three-piece second gear blocker ring assembly
using a twisting motion to fully seat.
4. Three-piece second gear blocker ring assembly
with thrust washer (44) to second gear (40).
A. BLOCKER TEETH
B. FEELER GAGE
C. CLUTCH TEETH
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