RATTLE OR KNOCKING NOISE FROM ENGINE COMPARTMENT (NEW PART). Saturn Saturn 1991

For 1990-2009 cars

# RATTLE OR KNOCKING NOISE FROM ENGINE COMPARTMENT (NEW PART)

#### SUBJECT: ---------- Rattle or Knocking Noise Coming from Engine Compartment (New Reverse Idler Gear System) 1991 SL2, SC With/MP7 Automatic Transaxle

Due to the release of a new Transaxle Service Manual, this bulletin supercedes Bulletin No. 91-T-01A, which should be discarded.

#### CONDITION:

----------- Some customers may comment on a rattle or knocking noise coming from the engine compartment, most often at 30 to 40 mph, in third or fourth gear, during a light throttle going up a slight grade or occasionally during a 1-2 upshift. A comment may also be made that the engine seems rough or noisy.

#### CONDITION:

---------- A reverse idler gear rattle in the transaxle can be caused by inherent four- cylinder engine rotation vibration. As a result, the reverse idler gear rocks back and forth and rattles on the reverse input and output gears. This rattle has no affect on transaxle performance.

#### CORRECTIVE ACTION:

A new reverse idler gear system that reduces running clearances in the reverse gear set has been released to correct this condition.

Transaxles built after January 8, 1991 have the new reverse idler gear system and can be identified by a "1" in the change code in the identification number found on the converter housing. Transaxels built before this change have a "0" in the change code. Refer to the following figure for change code location and description. This build number can be checked with the transaxle in the vehicle.

#### PROCEDURE:

----------- If a customer brings a vehicle in for the "Reverse Idler Gear Rattle" condition, it may be repaired by following these steps:

#### NOTE: The procedures mentioned in the following steps are located in the "Automatic Transaxle Out-of-Vehicle Repair" section of the "Automatic Transaxle Service Manual."

1. Remove the transaxle from the vehicle following the "Automatic Transaxle Removal" procedures.

2. After the transaxle has been removed from the vehicle, place the transaxle on a bench and follow Steps 1 through 19 of the "Automatic Transaxle Disassembly" procedures.

#### IMPORTANT: To remove the input shaft nut (Step 12, "Automatic Transaxle Disassembly" procedures), a thin-walled 23 mm, 12 pt socket must be used. The outside diameter of the socket cannot be larger than 30.3 mm.

3. Clean gasket material from all surfaces.

4. Remove the reverse idler gear, cap, shaft and bearing according to Step 4 in "Transaxle Case Disassembly."

Perform the following steps in order, under the "Case and Final Assembly" procedures. Steps not required for this bulletin have been omitted.

5. Install new reverse idler gear kit following Steps 3 through 8.

6. Perform Steps 12 through 15.

7. Perform Steps 21 through 42 and 44 through 50.

#### IMPORTANT: Step 43 is not required for this repair procedure.

8. Perform Steps 54 through 62.

9. Install the transaxle into the vehicle following the "Automatic Transaxle Installation" procedures.

#### PARTS REQUIREMENTS:

21001683 1 - Gasket - Cover to Case 21001684 1 - Gasket - End Cover to Case 21002265 1 - Gasket - Transaxle Case to Housing 21002227 1 - Pin - Lever Assembly & Shaft 21001680 1 - Nut - Input Shaft Clamp 21001679 1 - Nut - Output Shaft Assembly Clamp 21005984 1 - Kit - Reverse Idler Gear

#### Kit includes:

1 - Gear - Reverse Idler 1 - Shaft - Reverse Idler 1 - Cap -Reverse Idler Shaft (Retaining) 1 - Spacer - Reverse Idler Shaft (0-Ring)

CREDIT: To receive credit for this repair, submit a claim through the Saturn Dealer System as follows:

Case Type Failed Part Number ---------- ------------------ VW 21005984

#### IMPORTANT: The reverse idler gear kit must be indicated in the Parts System as the failed part.

Labor Description Operation Time Code ---------------------------- -------- ------- Remove and Replace Reverse T9510 7.4 hrs Idler Gear

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.