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Home >> Lexus >> 2008 >> IS 250 RWD V6-2.5L (4GR-FSE) >> Repair and Diagnosis >> Transmission and Drivetrain >> Differential Assembly >> Testing and Inspection >> Component Tests and General Diagnostics

Component Tests and General Diagnostics








DIFFERENTIAL: REAR DIFFERENTIAL CARRIER ASSEMBLY (for 4GR-FSE):

INSPECTION

1. INSPECT RUNOUT OF DIFFERENTIAL RING GEAR






(a) Using a dial indicator, measure the runout of the ring gear.
Maximum runout:
0.07 mm (0.0028 in.)
If the runout is greater than the maximum, replace the drive pinion, ring gear and differential case.
2. INSPECT AND ADJUST DIFFERENTIAL RING GEAR BACKLASH






(a) Set the dial indicator perpendicular to the end of the ring gear face.
(b) While holding the rear drive pinion companion flange, rotate the ring gear and measure the backlash.
Backlash::





HINT:
- Record the measured backlash to use as a reference for selecting a side gear shaft plate washer.
- Inspect tooth contact to use the result as a reference for selecting a side gear shaft plate washer.





(c) Select a side gear shaft plate washer that will set ring gear backlash within the specified range, and install it to the ring gear back side.














(d) Make the differential case bearing and side gear shaft plate washer snug by tapping on the ring gear with a plastic hammer.






(e) Set the dial indicator perpendicular to the end of the ring gear face.
(f) While holding the rear drive pinion companion flange rear, rotate the ring gear and measure the backlash.
Backlash::










(g) If the backlash is not within the specified range, select a side gear shaft plate washer that will set the ring gear backlash within the specified range and install it into the ring gear back side.






(h) Select a thicker side gear shaft plate washer so that the clearance between the case bearing outer race end on the ring gear teeth side and the carrier becomes zero or close to zero.






(i) Make the differential case bearing and side gear shaft plate washer snug by tapping on the ring gear with a plastic hammer.






(j) Set the dial indicator perpendicular to the end of the ring gear face.
(k) While holding the rear drive pinion companion flange, rotate the ring gear and measure the backlash.
Backlash::





If the backlash is not within the specified range, adjust the thickness of the right and left side gear shaft plate washers by an equal amount so that the backlash comes within the specified range.
3. INSPECT DIFFERENTIAL SIDE GEAR BACKLASH (for 2WD)






(a) Place a dial indicator on the tip of the pinion gear tooth at a right angle. Hold the side gear in the differential case and check that the backlash is 0 mm (0 in.).
If not, replace the rear differential case sub-assembly with a new one.
4. INSPECT DIFFERENTIAL SIDE GEAR BACKLASH (for 4WD)






(a) Measure the side gear backlash while holding 1 pinion gear toward the differential case.
Backlash:
0.05 to 0.20 mm (0.0020 to 0.0079 in.)
If the backlash is not within the specified range, install new side gear thrust washers that have a differential thickness than the current thrust washers. The new left and right thrust washers should be the same thickness as each other.
5. INSPECT DIFFERENTIAL SIDE GEAR BACKLASH (for 2WD)






(a) Hold the differential case in a vise between aluminum plates.
NOTE: Do not overtighten the vise.

(b) Place a dial indicator on the tip of the pinion gear tooth at a right angle. Hold the side gear in the differential case and check that the backlash is 0 mm (0 in.).
If not, replace the rear differential case sub-assembly with a new one.
6. INSPECT DIFFERENTIAL SIDE GEAR BACKLASH (for 4WD)






(a) Hold the differential case in a vise between aluminum plates.
NOTE: Do not overtighten the vise.

(b) Measure the side gear backlash while holding 1 pinion gear toward the differential case.
Backlash:
0.05 to 0.20 mm (0.0020 to 0.0079 in.)
If the backlash is not within the specified range, install new side gear thrust washers that have a differential thickness than the current thrust washers. The new left and right thrust washers should be the same thickness as each other.
HINT: Refer to the following table to select the 2 No. 1 side gear thrust washers.

Thrust washer thickness:






7. INSPECT RUNOUT OF REAR DRIVE PINION COMPANION FLANGE






(a) Using a dial indicator, measure the runout of the companion flange vertically and horizontally.
Maximum runout:
0.09 mm (0.0035 in.)
If the runout is greater than the maximum value, replace the rear drive pinion companion flange sub-assembly.
8. INSPECT DRIVE PINION PRELOAD






(a) Using a torque wrench, measure the preload of the drive pinion.
Preload (at starting):






Reused bearing:





If the drive pinion preload is not within the specified range, adjust the drive pinion preload or repair as necessary.
9. INSPECT TOTAL PRELOAD






(a) Using a torque wrench, measure the preload with the teeth of the drive pinion and ring gear in contact.
Preload (at starting):






Reused differential case bearing:





If the total preload is not within the specified range, adjust the total preload or repair as necessary.
10. INSPECT RUNOUT OF DIFFERENTIAL CASE ASSEMBLY
HINT: Perform this procedure only when the runout of the differential ring gear exceeds the specified maximum value.





(a) Install the case bearing outer races LH and RH to the case bearing inner races LH and RH respectively.
- Be sure to install the bearing outer races in each correct position.
- Do not damage the differential case bearing or ring gear.

(b) Install the differential case to the differential carrier.
(c) Install the right and left (back side and teeth side) side gear shaft plate washers so that there is no looseness on the case bearings.









(d) Align matchmarks on the bearing cap and differential carrier, and install the 2 bearing caps.
NOTE: Make sure that the right and left bearing caps are not interchanged.

(e) Tighten both bearing caps with the 4 bolts.
Torque: 85 Nm (870 kgf-cm, 63 ft-lbf)






(f) Using a dial indicator, measure the differential case runout.
Maximum case runout:
0.07 mm (0.0028 in.)
If the runout is greater than the maximum value, replace the differential case assembly with a new one.
(g) Remove the 4 bolts and 2 bearing caps.
NOTE: Do not swap bearing caps, as each cap is only suitable for its original location and installation direction on the carrier it was manufactured on.

(h) Remove the right and left bearing caps, 2 side gear shaft plate washers and differential case.
NOTE: Do not damage the differential case bearing or ring gear.

11. INSPECT TOOTH CONTACT BETWEEN RING GEAR AND DRIVE PINION






(a) Coat 3 or 4 teeth at 3 different positions on the ring gear with red lead primer.
(b) Rotate the ring gear in both directions.
(c) Inspect the tooth contact pattern.









(d) If the teeth are not contacting properly, use the following table to select a proper washer for correction.
- If the contact pattern is face contact or flank contact, tooth contact may be adjustable while keeping the backlash within the specified range.
- If the thickness of the drive pinion washer has been changed, adjust the backlash and measure the total preload.





12. INSPECT DIFFERENTIAL PINION AND SIDE GEAR (for 4WD)
(a) Check that there is no damage to the differential pinion gear and side gear.
If the differential pinion gear and/or side gear is damaged, replace them with new ones.
13. INSPECT DIFFERENTIAL CASE (for 4WD)
(a) Check that there is no damage to the differential case.
If the differential case is damaged, replace it.
14. INSPECT RUNOUT OF DIFFERENTIAL RING GEAR






(a) Install the case bearing outer races LH and RH to the case bearing inner races LH and RH respectively.
NOTE: Be sure to install the bearing outer races in each correct position.

(b) Install the differential case to the differential carrier.
(c) Install the right and left (back side and teeth side) side gear shaft plate washers so that there is no looseness on the case bearings.





HINT:
- If the case bearing is new, select a thinner side gear shaft plate washer and install it.
- If the case bearing is reused, install a side gear shaft plate washer with the same thickness as the removed one.





(d) Align the matchmarks on the bearing cap and differential carrier, and install the 2 bearing caps.
NOTE: Make sure that the right and left bearing caps are not interchanged.

(e) Tighten both bearing caps with the 4 bolts.
Torque: 85 Nm (870 kgf-cm, 63 ft-lbf)






(f) Using a dial indicator, measure the runout of the ring gear.
Maximum runout:
0.07 mm (0.0028 in.)
If the runout is greater than the maximum, replace the drive pinion, ring gear and differential case.






(g) Remove the 4 bolts and 2 bearing caps.
NOTE: Do not swap bearing caps, as each cap is only suitable for its original location and installation direction on the carrier it was manufactured on.

(h) Remove the 2 side gear shaft plate washers.









(i) Remove the right and left bearing caps, 2 side gear shaft plate washers and differential case.
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