Pinion & Ring General info

Adjusting Pinion and Ring Gear


Note: Careful adjustment of the drive pinion and ring gear is important to guarantee a long service life and quiet running for the final drive. This is why drive pinions and ring gears are matched during production and checked on special testing machines for the most favorable surface appearance and low noise levels in both directions of rotation. The position of quietest running is determined by moving the drive pinion in an axial direction, keeping the ring gear within specified backlash tolerances. The deviation "r" from the master gauge "Ro" is measured and inscribed on the outside periphery of the ring gear belonging to a pinion/ring gear set supplied as a spare part. Each set (drive pinion and ring gear) may only be replaced together.

Adjustment and Identification of Pinion/Ring Gear Sets

Service Sets




1 Code "K 935" means pinion/ring gear set with Klingelnberg teeth and 9:35 ratio. Number always has 3 digits.
2 Pair code 312 of pinion/ring gear set. Number always has 3 digits.
3 Deviation "r" in reference to master gauge of special testing machines used in production. Deviation "r" is always given in 1/100 mm and always has two digits.
For example: "25" means "r" = 0.25 mm. Other letters or digits concern manufacturing and material batches.
Ro Length of master gauge used in special testing machine.

Standard Sets






Important! In production the location of the drive pinion is given by distance Po (center of ring gear to back of pinion head). Deviation r on the ring gear and the pair code are omitted. Because deviation "r" is not given, the installed position of the drive pinion must be measured before removing same, when replacing parts which have direct influence on the installed position of the drive pinion.



X This data not required in production.
E Actual distance between ring gear shaft and face of pinion at point of quietest running for this set.
Vo Hypoid displacement =12 mm.

Recommended Sequence of Adjusting Pinion and Ring Gear




S1 = Shim for ring gear
S2 = Shim for ring gear
S3 = Shim for pinion
S4 = Shim for pinion

Note: When it becomes necessary to adjust the pinion and ring gear, it would be in the interest of economical procedures to keep to the following sequence.

1 Determine the total shim thickness "S tot" (S1 plus S2) for the specified pre-load of tapered roller bearing/differential.
2 Determine the total shim thickness "S tot" (S3 plus S4) for the specified pre-load of tapered roller bearing/drive pinion.
3 Divide total shim thickness "S tot" in S3 and S4 that the distance from center of ring gear to face of drive pinion is equal to distance "E" determined during production.
4 Divide total shim thickness "S tot" in S1 and S2 so that there is the specified amount of backlash between the ring gear and pinion.
The goal of adjustments is to relocate the point of optimal quiet running as was determined in the special testing machine during production.
Perfect results require absolute care and cleanliness during all assembly and measuring operations.

Adjustment Survey




The pinion and ring gear only have to be adjusted when repairs on the final drive require the replacement of parts having direct influence on the adjustment. Refer to the following table to avoid unnecessary adjustments!

Determining Installed Position of Drive Pinion (Actual Distance)
This operation is only necessary when deviation "r" is not given on the ring gear arid parts have to be replaced, which have direct influence on the drive pinion position. These would be both tapered roller bearings for drive pinion and transmission case.

Removing Differential
Complete universal gauge as shown in the list of tools, insert in transmission case and measure difference to "Ro" (max. deflection/point of reversal). Measured value will be equal to deviation "r".
Adjust drive pinion as described after replacing parts. Use the deviation "r" used for determination of shim thickness "S3".