WHINE/RATTLE NOISE COMING FROM TRANSAXLE

SUBJECT: Whine/Rattle Noise Coming from Transaxle (Remove and Re-Seat Reverse Idler Gear Shaft or Replace Transaxle Case)

MODELS AFFECTED: 1996 Saturns equipped with MP6/MP7 automatic transaxles

CONDITION: A whine and/or rattle noise that is related to vehicle speed may be heard while the vehicle is being driven. The noise is more noticeable during acceleration between 1800 and 3100 rpm, while in 2nd or 3rd gear, and below 1500 rpm during coasting.

CAUSE: The whine and/or rattle noise may be caused by a side-loaded reverse idler gear that reduces clearances between the reverse input and output gears. The lack of clearance can allow the reverse gears to whine and/or rattle, creating the condition mentioned in this bulletin.

CORRECTION: To correct this condition, follow the procedure in this bulletin.

PROCEDURES

1. Set park brake.

2. Place transaxle in Park.

3. Raise vehicle on a hoist.

4. Remove automatic transaxle end cover. (Refer to "End Cover" removal procedure in the "Automatic Transaxle In-Vehicle Service" section of the "1996 Revised Automatic Transaxle Service Manual.")

5. Remove 1st clutch and lst drive gear from input shaft. (Refer to "1st Clutch, 1st Drive Gear and 1st Driven Gear" removal procedure in the "Automatic Transaxle In-Vehicle Service" section of the "1996 Revised Automatic Transaxle Service Manual.")

IMPORTANT: Do not perform step 6 ("Remove 1st driven gear, sprag clutch, and thrust washer from the output shaft") of the " lst Clutch, 1st Drive Gear and lst Driven Gear" removal procedure. The driven gear can remain on the automatic transaxle when the reverse idler gear shaft is removed.

6. Remove reverse idler gear shaft cap bolts.

7. Remove reverse idler gear cap.

8. Remove reverse idler gear shaft.

IMPORTANT: The shaft contains O-rings which may cause difficulty in removing shaft. Rotating shaft while pulling will aid in shaft removal.

9. Remove O-rings and bearing from reverse idler gear shaft.

10. Examine reverse idler gear shaft bore in transaxle case for chamfer. (Refer to illustration for examples of a transfer case with and without chamfer.)

IMPORTANT: The chamfer will be approximately 4.0 mm (5/32 in.) in width. If chamfer is missing or less than 4.0 mm (5/32 in.), installation of the reverse idler gear shaft and 0-ring into the transaxle case will be more difficult.

11. Install new O-ring onto inboard (2nd gear side) side of reverse idler gear shaft.

12. Lube O-ring and case using a generous amount of petroleum jelly.

IMPORTANT: Failure to sufficiently lubricate O-ring and case may cause the O-ring to roll (twist) or be cut, which will cause transaxle noise.

13. Using a circular motion while applying light pressure on reverse idler gear shaft with thumb and fingers, install reverse idler gear shaft through gear into case and make sure the O-ring stays in position.

14. Check for proper positioning of the reverse idler gear shaft by pulling shaft out of case 2 mm (5/64 in.), and re-seating with your thumb. If the reverse idler gear shaft is properly positioned, the reverse idler gear shaft will not appear to be side-loaded or cocked. The reverse idler gear shaft should look centered in the cap bore.

NOTICE: Any side-loading or cocking of the reverse idler gear shaft may cause a noise condition.

15. If the reverse idler gear shaft is side - loaded or cocked, pull reverse idler gear shaft out of case 2 mm (5/64 in.) and re-seat using thumb. Verify proper installation by repeating step 14. It may be necessary to repeat this step two or three times until the reverse idler gear shaft is properly installed.

IMPORTANT: If reverse idler gear shaft cannot be centered (no side-loading or cocking), replace the transaxle case according to procedures in the "1996 Revised Automatic Transaxle Service Manual."

16. Once reverse idler gear shaft is properly installed, install reverse idler gear bearing on reverse idler gear shaft and into reverse idler gear.

17. Lube outboard 0-ring and install on outboard side of reverse idler gear shaft.

18. Install reverse idler gear cap using a twisting motion.

19. Install reverse idler gear cap bolts and torque.

IMPORTANT: Clean and lubricate bolts with Saturn Transaxle Fluid. Wipe off excess fluid and install.

Torque: 20 N-m (15 ft-lbs)

20. Install 1st drive gear and 1st clutch. (Refer to "lst Clutch, lst Drive Gear and 1st Driven Gear" installation procedure in the "Automatic Transaxle In-Vehicle Service" section of the "1996 Revised Automatic Transaxle Service Manual.")

21. After the input nut has been installed, verify proper transaxle operation by rotating the input shaft by turning the lst clutch housing in both directions. The clutch housing should turn freely in both directions.

* If input shaft turns freely in one direction only, the first clutch is binding. Refer to proper repair procedure in the "1996 Revised Automatic Transaxle Service Manual."

* If input shaft will not turn freely in either direction, 2nd, 3rd or 4th clutch is binding. Refer to proper repair procedure in the "1996 Revised Automatic Transaxle Service Manual."

* If the input shaft turns freely in both directions, place vehicle in Neutral and proceed to next step.

IMPORTANT: Placing the vehicle in Neutral allows the axle to be rotated, which helps align the tubes with the bushings in the input and output shaft during end cover installation.

22. Install automatic transaxle end cover. (Refer to "End Cover" installation procedure in the "Automatic Transaxle In-Vehicle Service" section of the "1996 Revised Automatic Transaxle Service Manual.")

23. Verify repair by driving vehicle under conditions that condition was observed.

24. If condition still exists and reverse idler gear shaft bore chamfer was less than 4.0 mm (5/32 in.), replace transaxle case according to procedures in the "1996 Revised Automatic Transaxle Service Manual."

PARTS REQUIREMENTS: 21001680 Nut-Input Shaft 21001684 Gasket-Trans Cover 21002426 Spacer-Rev Idler Gr (O-ring) (Qty-2) 09440157 Pin - Frt Lwr Cont Arm Cot 21006320 Nut-Trans Mt to Cradle 21002622 Case/A-Trans

CLAIM INFORMATION: To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System as follows:

Labor Case Operation Type Description Code Time ---- ----------- --------- -----

VW Remove and Re-Seat Reverse T9711 1.9 hrs Idler Gear Shaft

VW Replace Transaxle Case K7800 9.1 hrs

NOTE: For alignment times, refer to Labor Operation E2020. When claiming alignment, relate the alignment to the repair. E2020 will only be part of K7800.

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.