Ring Gear
RING GEAR, ADJUSTING(Adjusting differential)
The ring gear must be adjusted if any of the following have been replaced:
- Transmission housing
- over for differential
- Tapered roller bearings for differential
- Differential housing
- Ring and pinion gearset
Refer to the adjustment table found under General Information (Read First)
Determining Total Shim Thickness Stotal (S1 + S2)
(Adjust preload on differential tapered roller bearing)
- Pinion removed
Refer to the following work sequence:
- Remove oil seals, differential tapered roller bearing outer races, and shims, refer to Differential Gear and Carrier Disassembly/Assembly. Service and Repair
- Install tapered roller bearing outer race and a 1.5 mm thick shim (S2) in transmission housing.
- Press bearing outer race (without a shim) into differential cover.
- Install differential into housing without drive gear for vehicle speed sensor.
Ring gear is on left side (differential cover side).
- Mount dial indicator holder on housing and place magnetic plate VW385/17 on differential.
- Zero dial indicator (3 mm range) with a preload of 1 mm.
A in illustration = Dial indicator extension approx. 30 mm (1-3/16 in) long
- Move differential up and down, read and record axial play on dial indicator gauge.
Example:
Axial play = 0.60 mm
CAUTION: Do not turn the differential when measuring, otherwise the bearings will settle and falsify the results.
Calculating Stotal (S1 + S2)
Example:
Installed shim S2 + Measured axial play + Specified preload = Stotal
1.50 mm + 0.60 mm + 0.40 mm = 2.50 mm
Distribution Of Shims S1 And S2
Example:
Stotal - Thickness of installed shim (S2) = Shim S1
2.50 mm - 1.50 mm = 1.00 mm
- Select shims from "S1 and S2 Shims: table shown below.
- Place shim S1 of correct thickness behind tapered roller bearing outer race in differential cover.
- Lubricate bearings with gear oil.
Measure Turning Torque
A In illustration = Torque gauge 0-600 Ncm (0-53 inch lbs.)
- Specifications:
- New bearings: 70-150 Ncm (6-13 inch lbs)
- Used bearings: 20-40 Ncm (2-4 inch lbs)
NOTE:
^ Ring gear turning torque can also be measured at the pinion:
For new bearings, it must be 50-70 Ncm (4.5-6 inch lbs) higher than pinion turning torque.
^ After the gear set has been readjusted the pinion adjustment and subsequent check must be carried out, refer to Pinion Gear.
Measuring Backlash
Pinion installed with S3 and S4 shims
- Install differential.
- Turn differential several times in both directions to settle tapered roller bearings.
- Attach dial indicator holder VW387 on housing.
- Install setting tools for ring gear VW521/4 and VW521/8.
- Set lever VW388 to dimension -a- = 70 mm.
- Turn ring gear to stop, then zero dial indicator.
- Turn ring gear back and read off backlash.
- Note reading.
- If pinion turning torque is too low, install separating tool (A in illustration), e.g. Kukko 17/2 to prevent pinion from turning.
- Take three more readings, turning ring gear 90° each time.
- Add four readings together and calculate average backlash.
CAUTION:
^ If measured readings differ from one another by more than 0.06 mm there is something wrong with installation of the ring gear or the gear set
^ Recheck assembly work and if necessary, replace the gear set.
Calculating Average Backlash
Example:
1st reading + 2nd reading + 3rd reading + 4th reading + Total / 4 = 0.49
0.49 mm + 0.48 mm + 0.50 mm + 0.49 mm = 1.96 mm / 4 = 0.49 mm
Determining Shim S2 Thickness
Example:
Installed shim thickness - Average backlash x 1.17 (fixed value) + Lift (constant) = S2
1.50 mm - (0.49 x 1.17 = 0.57 mm) + 0.20 mm = 1.13 mm
Determining Shim S1 Thickness
Example:
Stotal - S2 = S1
2.50 mm - 1.13 mm = 1.37 mm
Select S1 And S2 Shims From Table Shown Below
S1 And S2 Shims:
CAUTION:
^ Part numbers are listed here for reference only.
^ Always check with your Parts supplier for the latest information.
Example:
1st shim + 2nd shim = Total S2
0.60 mm + 0.55 mm = 1.15 mm
1st shim + 2nd shim = Total S1
0.70 mm + 0.65 mm = 1.35 mm
Check Measurements
- After installing shims S1 and S2, again measure backlash four times around circumference.
A in illustration: Separating tool, e.g. Kukko 17/2
Specification: 0.15 - 0.25 mm
CAUTION: The individual results must not differ from each other by more than 0.05 mm.