Contents Wiring diagrams Section: Transfer Case All sections

Transfer Case - Nvg 900: Other Saturn VUE I

Transfer Case 2 illustrations ~453 words

Sealers, Adhesives, and Lubricants

ApplicationType of MaterialSaturn Part Number
United States
Drain Plug ThreadsSealant21485278
Fill Plug ThreadsSealant21005994
Gear Lubricant GM VersatrakSynthetic Gear Oil12378514
Side Cover-to-HousingSealant1052943
Side Cover BoltsThread Locker12345382

Sealers, Adhesives, and Lubricants

Scheme 13

Scheme 13: Transfer Case Disassembled View
CalloutComponent Name
1Nut
2Flange
3Oil Seal
4Slinger Washer
5Bearing
6Bearing Cup
7Axle Shaft Oil Seal - Left Side
7Axle Shaft Oil Seal - Right Side
8Housing
9Vent
10Hollow Dowel
10Hollow Dowel
11Collapsible Spacer
12Bearing Cup
13Bearing
14Shim
15Pinion Shaft
16Vent Baffle
17Shim
18Cup
19Differential Bearing
20Ring Gear
21Differential Case
22Bolt
23Inner Bearing
24Bearing
25Bracket
26Bolts
27Fill Plug
28Axle Shaft Oil Seal - Right Side
29Bolt
30Side Cover
31Shim
32Bearing Race
33Drain Plug

Intermittent

Test the vehicle under the same conditions that the customer reported in order to verify the system is operating properly.

Noisy in Drive

CauseCorrection
Inspect for the proper gear oil levels prior to performing system diagnosis.
Loose propeller shaft constant velocity jointsTighten the bolts as required. Refer to Propeller Shaft Replacement in Propeller Shaft.
Worn propeller shaft constant velocity jointsReplace the propeller shaft assembly. Refer to Propeller Shaft Replacement in Propeller Shaft. A worn propeller shaft constant velocity joint may create a clicking, grinding, or snapping type of noise.
Worn or loose center bearing assemblyReplace the center bearing assembly as required. A worn center bearing assembly may cause vehicle vibration or a grinding or squealing type of noise.
Worn universal jointsReplace the universal joints as required. A worn universal joint may create a clicking or snapping type of noise.
Worn axle shaft constant velocity jointsReplace/repair the constant velocity joints as required. A worn axle constant velocity joint may create a clicking, grinding, or snapping type of noise.
Rear axle noiseRefer to Diagnostic Starting Point - Transfer Case .
Loose mounting bracketTighten the bracket bolt or replace the bracket as required.
Loose transfer case-to-transmission mounting boltsTighten the bolts as required.
Incorrect gear oilReplace with GM gear oil Saturn P/N 12378514.
Bearing noise within the transfer caseA grinding or roar type noise will increase or decrease relative to the vehicle speed. Check for proper fluid level. Fill as required. If the noise continues, replace the unit.
Gear set whine noise within the transfer caseWhine type noises will increase or decrease relative to the vehicle speed, approximately 80-90 km/h (50-60 mph). Check for the proper fluid level. Fill as required. If the noise continues, repair or replace the internal components as required. Contributing factors may include: Incorrect backlash between the gear sets Worn or damaged gear teeth Transaxle assembly noise Rear axle noise

Noisy in Drive

Noisy When Coasting

CauseCorrection
Inspect for the proper gear oil levels prior to performing system diagnosis.
Loose propeller shaft mounting bolts.Tighten the bolts as required. Refer to Propeller Shaft Replacement in Propeller Shaft.
Worn propeller shaft constant velocity jointReplace the propeller shaft assembly. Refer to Propeller Shaft Replacement in Propeller Shaft. A worn propeller shaft constant velocity joint may create a clicking, grinding, or snapping type of noise.
Worn or loose center bearing assemblyReplace the center bearing assembly as required. A worn center bearing assembly may cause vehicle vibration or a grinding or squealing type noise.
Worn universal jointsReplace the universal joints as required. A worn universal joint may create a clicking or snapping type noise.
Worn axle shaft constant velocity jointsReplace/repair the constant velocity joints as required. A worn axle shaft constant velocity joint may create a clicking, grinding, or snapping type noise.
Rear axle noiseRefer to Diagnostic Starting Point - Rear Drive Axle in Rear Drive Axle.
Loose mounting bracketTighten the bracket bolts or replace the bracket as required.
Loose transfer case-to-transmission mounting bolts.Tighten the bolts as required.
Incorrect gear oilReplace with GM gear oil Saturn P/N 12378514.
Bearing noise within the transfer caseA grinding or roar type noise will increase or decrease relative to the vehicle speed. Check for proper fluid level. Fill as required. If the noise continues, replace the unit.
Gear set whine noise within the transfer caseWhine type noises will increase or decrease relative to the vehicle speed, approximately 80-90 km/h (50-60 mph). Check for proper fluid level. Fill as required. If the noise continues, repair or replace the internal components as required. Contributing factors may include: Incorrect backlash between the gear sets Worn or damaged gear teeth Transaxle assembly noise Rear axle noise

Noisy When Coasting

Housings

  1. Clean all case/housings in solvent.
  2. Inspect for the following: Damaged gasket sealing surfaces (1) A loose, damaged, or restricted vent tube (2) Worn, scored, or loose bearing races or worn bearing race bores (3) Damaged drain plug (5) Damaged fill plug hole threads (4) Damaged bolt threads (6) Damaged oil seal bores (7)

Gears and Shafts

  1. Clean the gears and shafts in solvent.
  2. The ring gear and pinion must be inspected for proper wear and pattern. The end of the gear tooth farthest away from center of ring gear (1) is the heel end of the tooth. The end of the gear tooth nearest center of ring gear (2) is the toe end of the tooth. The side of the tooth that curves inward or is concave (3) is considered the coast side of the tooth. The side of the tooth that curves outward or is convex (4) is considered the drive side of the tooth.
  3. Inspect the pinion shaft for the following: Wear, pitting, or discoloration by heat on the gear teeth (1) Worn or scored shaft (2) Worn or damaged splines (3) Damaged threads (4) Worn bearings (5)
  4. Inspect the pinion flange seating surface (2) for wear, damaged bolt threads (3) and worn or damaged splines (1).

Bearings and Races

  1. Inspect the bearing rollers and races for the following: Pitting Scoring or grooves Excessive wear or other damage
  2. Inspect bearing rollers and races for heat discoloration. Heat discoloration ranges from a faint yellow to a dark blue color. This discoloration may result from an overload or improper lubrication. Excessive heat causes softening of the rollers and races. Bearing races with a sign of heat discoloration must be replaced.

Scheme 14

Scheme 14: Transfer Case Description and Operation

The transfer case (PTU) in this vehicle consists of an aluminum housing and a ring and pinion power transfer system.

The PTU transfers torque/power to the rear differential, gerotor pump design, via a two-piece propshaft assembly.

The on-demand rear differential distributes variable torque/power to the rear wheels via individual axle shafts.

The on-demand system operates as follows: only when front wheel slippage is encountered torque/power is proportioned to the rear wheels, as long as there is not front-to-rear speed difference; there is no torque/power to the rear wheels.

When front-to-rear wheel slippage does not occur, the rear differential, gerotor, pumps fluid stored in the sump to a piston that actuates a clutch pack, which then distributes torque/power to the rear wheels.