A d j u s t i n g P i n i o n / R i n g G e a r - G e n e r a l I n f o r m a t i o n

Accurate adjustments of the pinion and ring gear are immensely important for the service life and smooth running of the final drive. This is why pinions and ring gears are paired during manufacture and checked in special machines for tooth pattern and quietness in both directions of rotation. The position of smoothest running is determined by moving the pinion in an axial direction, whereby the ring gear is lifted out of the no-play meshing position far enough so that the backlash will be kept within specified tolerances.

Deviation "r", in reference to master gage "Ro ", of the special testing machine used in manufacturing is measured and recorded on the outer periphery of the ring gear. Pinion and ring gear must always be replaced together.

Ro - Length of master gage used in special testing machine "Ro" = 46.60 mm.

r - Deviation from master gage used in special testing machine in manufacturing. "r" is always given in 1/100 mm. Example: "32" means r = 0.32 mm.

53 - Shim behind head of pinion.

54 - Shim opposite head of pinion.

Objective of adjustments must be to regain the maximum degree of quiet running, as had been determined by the special testing machine in manufacturing.

1 - Mark "G 1237" means Gleason pinion/ring gear, ratio 12 : 37.

2 - Matching pair number of pinion/ring gear set.

1. Heat pinion bearing inner race (large bearing) to about 100 °C/212 °F, install on pinion without shim and press on with a force of about 3 tons.

2. Heat pinion bearing inner race (small bearing) to about 100 °C/212 °F, install on pinion with 1.1 mm thick shim (arrow) and press on with force of about 3 tons.

Pinion would hit housing while measuring and cause incorrect readings, if shim is omitted.

3. Install final drive housing cover without seals. Tighten all bolts to specified torque.

4. Install pinion and pinion cover. Tighten all bolts to specified torque.

5. Place VW 387 on housing and VW 385/17 on pinion. Install dial gage and adjust to zero.

6. Move pinion up and down without turning it several times and note dial gage reading.

Readings would be wrong if pinion is turned.

7. Add 1.1 mm for installed shims, 0.15 mm for bearing preload and 0.10 mm for bearing settling to dial gage reading. This results in Stot.

Example: Dial gage reading Installed shim Bearing preload Bearing settling Total shim thickness

8. Remove pinion. Take out installed shim (1.1. mm) and install shims of total thickness (3.16 mm in example) at small bearing.

9. Install pinion again and check deviation "e". Deviation "e" is the difference between the actual measurement R and the design measurement Ro.

10. Turn pinion in both directions several times.

11. Place VW 385/28 on pinion.

12. Set adjusting ring of VW 385/1 at distance a. a = approx. 82 mm.

14. Screw adjusting ring (opposite ring gear) into case far enough so that it is flush with housing.

15. Insert universal gage in housing and screw in adjusting ring (behind ring gear). Do not place dial gage pin on end gage.

16. Pull 2nd centering disc outward with movable adjusting ring until universal gage can just barely be turned by hand.

13. Assemble VW 385/1 according to figure (dial gage extension VW 385/15 = 9.3 mm). Install VW 385/30 and set dial gauge at zero with 3 mm preload.

17. Turn universal gage until dial gage pin touches end gage and shows maximum deflection (return point). Take dial gage reading.

18. Note measured distance "e" (example: 1.88 mm) and determine thickness of shims S3 and S4.

A r r a n g e m e n t o f G a g e s t o D e t e r m i n e D e v i a t i o n e

19. Determine thickness of shim "S3". "S3" = e - r


Dial gage reading "e" 1.88 mm

Thickness of shim "S3" 1.56 mm

20. Select shims from table.

21. Determine thickness of shim "S4". "S4" = "Stot." - "S3"


Total shim thickness 3.16 mm

Shim thickness "S3" - 1,56 mm

Shim thickness "S4" 1.60 mm

22. Select shims from table.

20. Select shims from table.


Shim to Range be installed

Part Number

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