Pontiac FIREBIRD 1972 Service Manual page 873

7D-4 1972 PONTIAC SERVICE MANUAL
1. Bearing Retainer
2. Main Drive Gear
Fig. 7 0 - 1 Cross Section of Transmission
10. 1st Speed Synchronizer Blocker Ring 19. Countershaft Bearing Spacer
1 1. 1 st Speed Gear 20. Magnet
3. 4th Speed Blocking Ring
12. 1st speed Gear Sleeve
2 1. ~ o ~ n t e r s h a f t Bearing Rollers ( 1 12)
4. 3 r d & 4th Speed Synchronizer Sleeve 13. Reverse Gear 22. Countershaft
5.
3rd Speed Synchronizer Blocker Ring
14. Speedometer Drive Gear 23. Oil Slinger
6. 3 r d Speed Gear 15. Mainshaft 24. Reverse Idler Gear Shaft
7. 2nd Speed Gear 16. Reverse Idler Shaft Lock Pin 25. Thrust Washer
8. 2nd Speed Blocker Ring
17. Reverse Idler Gear (Rear) 26. Reverse Idler Gear (Front)
9. 1st
&
2nd Speed Synchronizer Sleeve 18. Countergear
The front end of mainshaft is piloted in bearing rollers set
into the hollow end of the main drive gear and the rear end
is carried by a heavy-duty ball bearing located at the rear
end of the transmission case.
The countershaft gear is carried on a double row of bear-
ing rollers positioned at both ends of the gear, while thrust
is taken on thrust washers located at front and rear of the
gear.
The 1st speed gear has a loose fit sleeve, lining its inner
bore, which enables the gear to float freely on the main-
shaft, while the reverse speed gear has splines on its inner
bore to prevent the gear from rotating on the mainshaft
but allow forward and rearward movement of this gear.
The two synchronizer assemblies are splined to the main-
shaft so that they can impart torque to the rnainshaft
whenever they engage a rotating gear.
The two-piece reverse idler gear is carried on press-fit
bronze bushings and thrust is taken on thrust washers
OPERATION
located between the front of the gear and the back of the
reverse idler thrust boss and the rear of the gear and the
The main drive gear, 3rd speed gear, 2nd speed gear, 1st
reverse idler gear shaft boss in the rear extension. speed gear and reverse idler gears are in constant mesh