Measure gear backlash between crown wheel and pinion, correct if necessary - AR35.31-P-0550-25A

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TEST VALUES FOR REAR AXLE CENTER ASSEMBLY GEAR SET

Number	Designation		Model 129	Model 140
BE35.31-P-1002-03A	Gear backlash between crown wheel and pinion	mm	0,08-0,14	0,08-0,14

TEST VALUES FOR REAR AXLE CENTER ASSEMBLY GEAR SET

Number	Designation		Model 170	Model 202
BE35.31-P-1002-03A	Gear backlash between crown wheel and pinion	mm	0,08-0,14	0,08-0,14

TEST VALUES FOR REAR AXLE CENTER ASSEMBLY GEAR SET

Number	Designation		Model 203	Model 208	Model 209
BE35.31-P-1002-03A	Gear backlash between crown wheel and pinion	mm	0,10-0,16	0,08-0,14	0,10-0,16

TEST VALUES FOR REAR AXLE CENTER ASSEMBLY GEAR SET

Number	Designation		Model 210	Model 220.063/065/067/083/ 084/087/165/167/183/ 184/187
BE35.31-P-1002-03A	Gear backlash between crown wheel and pinion	mm	0,08-0,14	0,08-0,14

Fig 1: Identifying Spreader (140 589 05 31 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 2: Identifying Backlash Measuring Instrument (140 589 08 21 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Insert and clamp backlash measuring instrument (037) with dial indicator in right-hand bore in differential housing.
Position dial indicator on "0" under 3 mm preload.
Hold drive pinion at joint flange and alternately press ring gear upwards and downwards alternately, reading off the gear backlash in the process.
Carry out the measurement 4 times. Turn crown wheel approx. 90° further each time.
The adjustment of the tapered roller bearings and gear set is OK if the spread dimension (expansion) of the rear axle housing and the gear backlash are within the range of the specifications. If these values are not achieved, the adjustment must be repeated using thinner or thicker locking rings as appropriate.
Remove gear backlash measuring instrument (037).

Fig 3: Removing Gear Backlash Measuring Instrument
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

1st example

Measurement: Gear backlash is correct but spread dimension of the rear axle housing is too small, e.g. 0.05 mm measured spread dimension value.

Correction: Fit a 0.05 mm thicker circlip on both sides in each case, the gear backlash may change slightly in the process.

2nd example

Measurement: Spread dimension is correct, but the gear backlash is too large.

Correction: On the left assembly side a circlip should be installed which is thinner by the missing amount. Install a thicker locking ring on the right-hand side (crown wheel side). If the gear backlash is too low, install the locking rings in the opposite sequence.