Vehicle Vibration Between 77 and 87 KM/H (48 and 54 MPH) #96-T-52A - (Sep 30, 2003)

1994-1999 Saturn vehicles

Condition

Some customers may comment about a vehicle vibration that occurs between 77 and 87 km/h (48 and 54 mph) on smooth road surfaces.This vibration is most noticeable in the vehicle's floorboards and/or in the seat cushions. It only occurs within the specified speed range of 77 and 87 km/h (48 and 54 mph) and only on smooth to very smooth road surfaces.

Cause

This condition may be caused by insufficient damping between the engine cradle and the powertrain.

Correction

Verify condition and if required, install powertrain damper kit.

Procedure

Since the powertrain damper kit is designed to correct a very specific vibration, it is important that all other possible causes of vehicle vibration be eliminated before installing the kit. Since a road test is necessary, it is important that the following checks are performed.

Important

Perform all of the following checks before road testing vehicle.

Check for debris build-up on the tires and/or road wheels.

• Check tires for tread distortions, separations, bulges from impact, and abnormal or excessive wear.
• Check for bent and/or damaged road wheels.
• Check for missing or loose road wheel weights.
• Check for loose or missing road wheel lug nuts.
• Check for proper tire bead seating on rim of road wheel.
• Make sure the road wheel and tire assemblies are within specification for radial and lateral runout.
• Make sure the road wheel and tire assemblies are correctly balanced to the nearest 0.10 oz.
• Check front suspension components for excessive wear and/or damage:




1. Check if cradle is bent.
2. Check tension strut bushings for wear or damage.
3. Check lower control arms for worn ball studs, worn bushings, or bent arms.
4. Check steering gear for wear or damage.
5. Check inner and outer tie rod ends for wear or damage.
6. heck strut assemblies for wear, binding and to make sure they are not bent.
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  Check rear suspension components for excessive wear and/or damage:
1. Check components for wear or damage.
2. Check if the cross support is bent.
3. Check trailing arms to see if the bushings are worn or if the arms are bent.
4. Check lateral links to see if the bushings are worn or if the arms are bent.
5. Check stabilizer bar on vehicles so equipped for worn or missing bushings, and to verify that the stabilizer bar is not bent.

After checking the above items, road test the vehicle on a smooth road surface while very gradually accelerating the vehicle from 77 to 87 km/h (48 to 54 mph). If the vehicle is equipped with cruise control, it is convenient to use it to accelerate the vehicle at 2 km/h (1 mph) increments.

A vibration may start between 77 and 87 km/h (48 to 54 mph). It may grow more pronounced as the vehicle maintains a steady speed within the 77 to 87 km/h (48 to 54 mph) speed range on a smooth surface. Any rough areas in the road such as expansion joints or any irregularities in the road surface will interrupt the vibration, causing a need to restart the road test.

Install the powertrain damper kit under these circumstances only:

• When all other possible causes for vehicle's vibration have been eliminated.
• When a continuous vibration occurs only between 77 and 87 km/h (48 and 54 mph) and the vibration is most pronounced in the vehicle's floorboards and seat cushions.

The powertrain damper kit comes with the damper installed to the upper bracket. The powertrain damper kit has two steel washers and two rubber grommets attached to the damper's shaft. One M8 x 20 mm bolt and one M8 nut (used for second design vehicles), and one M6 nut are included in each kit. Each kit contains a lower bracket. There are two lower bracket designs, one for automatic transaxles and one for manual transaxles.

The powertrain damper kit installs between the left midrail and the transaxle. Utilizing the forward battery tray fastener(s), the upper bracket attaches to the midrail, underneath the battery tray. The lower bracket (a modified transaxle strut bracket) attaches to the transaxle at the same location as the transaxle strut bracket. The damper itself attaches to the upper bracket with an M10 x 40 mm bolt and to the lower bracket with steel washers and the rubber grommets held in place with an M6 nut.

The following procedures are separated into four procedures:

1. Damper Bench Assembly to Lower Bracket (Required for all vehicles)
2. Battery and Battery Tray Removal (Required for all vehicles)
3. Powertrain Damper Kit Installation-First Design Vehicles (First Design - 1994 and early 1995 Saturns built before and including VIN SZ154030)
4. Powertrain Damper Kit Installation-Second Design Vehicles (Second Design - 1995 vehicles built after and including VIN SZ154031 and 1996-1999 vehicles)

Important

All 1994 and early 1995 Saturns used two vertical and two horizontal fasteners to secure the battery tray to the vehicle. (This is called the First design.) In September 1994, the front horizontal battery tray fastener was removed; all vehicles built after and including VIN SZ154031 have only the rearward horizontal battery tray fastener. (This is called the Second design.)

On 1995 vehicles built after and including VIN SZ154031 and 1996-1999 vehicles, a reinforcing bracket attached to the rear horizontal battery tray fastener helps support the battery tray. The procedure to install the powertrain damper kit differs if the vehicle has one or two horizontal battery tray fasteners.

Damper Bench Assembly to Lower Bracket

(Required for all vehicles)

1. Remove the first rubber grommet and the first steel washer from the damper shaft.
2. Install the damper shaft into the appropriate lower bracket; install the rubber grommet and then the steel washer onto the damper shaft.
3. Install the M6 nut to the damper shaft. To tighten the nut, hold the "flats" on the damper shaft with a 7 mm wrench.
Tighten

Tighten the M6 nut to the damper shaft nut to 10 N·m (89 lb in).

4. After damper is assembled, proceed to Battery and Battery Tray Removal.

Battery and Battery Tray Removal

(Required for all vehicles)

1. Remove air induction system.





Caution

TO PREVENT ARCING WHEN REMOVING THE BATTERY, THE NEGATIVE BATTERY CABLE MUST BE REMOVED FIRST.

2. Disconnect the negative battery cable from the battery.
3. Disconnect the positive battery cable from the battery.
4. Remove hold-down retaining nut and screw, and lift off battery hold-down retainer.
5. Lift battery out of vehicle, and place in a safe location.




6. Remove bolts retaining battery tray to vehicle and remove battery tray.
7. 1995 Second Design and 1996 - 1999 battery tray shown.




8. Proceed to one of the two following procedures, depending on whether the vehicle has a First or Second design battery tray.

Powertrain Damper Kit Installation (First Design - 1994 and early 1995 Saturns built before and including VIN SZ154030)

1. Place the battery tray in a vice and use a rat-tail file to elongate the forward vertical bolt hole. Create an oblong slot that measures 18 mm (23/32 in.). (This is approximately an 8 mm [5/16 in.] increase in the size of the existing bolt hole.)

Important

Do not make the slot any wider than the original width of the hole. Make sure to slot the hole outboard (toward the left front tire if the battery tray was mounted in the vehicle).








2. Remove the transaxle strut. Refer to "Transaxle Strut" in the "Powertrain Mounts" section of the "Chassis Service Manual."
3. Remove the two transaxle strut bracket fasteners and remove the transaxle strut bracket and discard.
4. Install bench-assembled damper kit by securing it in place with the two transaxle strut bracket fasteners.
Tighten

Tighten the bench - assembled damper kit to 54 N·m (40 lb ft).





5. Install transaxle strut and fastener to the new modified transaxle strut bracket.
Tighten

Tighten the strut and tastener-to-transaxle strut bracket to 70 N·m (52 lb ft).





6. Install battery tray and loosely install all four battery tray bolts, starting with forward horizontal bolt. Tighten all four bolts after they are all installed.
Tighten

Tighten the forward vertical and horizontal battery tray bolts to 20 N·m (15 lb ft).

7. Make sure the damper-to-upper bracket bolt is properly torqued.
Tighten

Tighten the rearward vertical and horizontal battery tray bolts to 10 N·m (15 lb ft).

Important

The damper-to-upper bracket bolt must be properly torqued.

8. Install the transaxle strut-to-midrail bolt.
Tighten

Tighten the strut and tastener-to-transaxle strut bracket to 70 N·m (52 lb ft).





9. Make sure the battery cable ends are clean.
10. Make sure that the battery is in good physical condition (e.g., no cracks, or obvious damage) and that the terminals are clean.
11. Install battery carefully in the battery tray; make sure that the terminals do not short against any metal during the installation.
12. Install the battery hold-down retainer, locking the battery into the battery tray. Install and tighten the hold-down retainer nut and screw.
Tighten

Tighten the battery hold-down retainer to 9 N·m (80 lb in).

13. Install the positive battery cable first.
Tighten

Tighten the positive battery cable to 17 N·m (151 lb in).

14. Install the negative battery cable last.
Tighten

Tighten the negative battery cable to 17 N·m (151 lb in).

15. Install air induction system.

Important

It may be necessary to use a 2 mm (5/64 in.) thick shim between the forward mounting foot on the air cleaner assembly and the midrail.

16. Road test vehicle to verify that vibration has been repaired.

Powertrain Damper Kit Installation (Second Design - 1995 Saturns built after and including VIN SZ154031 and 1996-1999 Vehicles)

Important

Do not make the slot any wider than the original width of the hole. Make sure to slot the hole outboard (toward the left front tire if the battery tray was mounted in the vehicle).

1. Place the battery tray in a vice and use a rat-tail file to elongate the forward vertical bolt hole. Create an oblong slot that measures 18 mm (23/32 in.). (This is approximately an 8 mm [5/16 in.] increase in the size of the existing bolt hole.)




2. Remove the forward "tab" and corner of battery tray that was used to retain the J-nut on first design vehicles.
• Place the battery tray in a vice; mark a drill pilot location 4.76 mm (3/16 in.) in from the upper inside corner of the indentation.
• Using the marked pilot location, drill a 3/8 in. hole in the battery tray.
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  Notice

  It is essential to maintain a rounded corner in the cutout section of the battery tray. This "roundness" will help relieve stress at the corner and prevent the battery tray from cracking.

  Using a hacksaw, cut in from the bottom and the side of the battery tray to remove the remainder of the "tab" and corner of battery tray.







3. Remove the transaxle strut. Refer to "Transaxle Strut" in the "Powertrain Mounts" section of the "Chassis Service Manual."
4. Remove the two transaxle strut bracket fasteners and remove the transaxle strut bracket.
5. Install bench-assembled damper kit by securing it in place with the two transaxle strut bracket fasteners.
Tighten

Tighten the bench - assembled damper kit to 54 N·m (40 lb ft).





6. Finger start forward vertical battery tray bolt through the damper kit's upper bracket. Tighten loosely to secure bracket location while making sure that the horizontal hole in the upper bracket aligns with its mating hole in the midrail.
7. Raise vehicle on a hoist.
8. Remove left front road wheel.




9. Locate the hole in the midrail that was used on earlier vehicles to secure the battery tray with the forward horizontal battery tray bolt.




10. Locate the forward hole that was used in first design vehicles to secure the battery tray to the midrail. Then using a metric or SAE dimension stepped uni-bit, enlarge the hole to 17 mm or 11/16 in.

Important

This hole will be used to gain access to the inside of the midrail for installation of the M8 x 20 mm bolt.





11. To install M8 x 20 mm bolt, use an extension and a 10 mm socket. Use a magnetic socket or secure the bolt in the socket with RTV.




12. Slide bolt, socket and extension through 17 mm or 11/16 in. hole created in a previous step. Slide the bolt through the opposite hole in the inside of the midrail and through the hole in the damper kit's upper bracket.




13. Install M8 nut onto bolt and tighten.
Tighten

Tighten the M8 nut to 30 N·m (22 lb ft).





14. Using 3M WINDO-WELD Primer (Black) (P/N 08643) or equivalent, prime edge of 17 mm or 11/16 in. hole enlarged in outside of midrail.
15. Install road wheel.
Tighten

Tighten the road wheel to 140 N·m (103 lb ft).

16. Lower vehicle from hoist.




17. Install transaxle strut to the new modified transaxle strut bracket.
Tighten

Tighten the transaxle strut to 70 N·m (52 lb ft).





18. Install battery tray; loosely install all three battery tray bolts, starting with horizontal bolt. Tighten all three bolts after they are all installed.
Tighten

Tighten the forward vertical battery tray bolt to 20 N·m (15 lb ft).

Tighten

Tighten the rearward vertical battery tray bolt to 10 N·m (89 lb in).

Tighten

Tighten the horizontal battery tray bolt to 10 N·m (89 lb in).

19. Make sure the damper-to-upper bracket bolt is properly torqued.
Tighten

Tighten the damper-to-upper bracket bolt to 70 N·m (52 lb ft).

Important

The damper-to-upper bracket bolt must be properly torqued.

20. Install transaxle strut-to-midrail.
Tighten

Tighten the transaxle strut-to-midrail to 70 N·m (52 lb ft).





21. Make sure the battery cable ends are clean.
22. Make sure that the battery is in good physical condition (e.g., no cracks, or obvious damage) and that the terminals are clean.
23. Install battery carefully in the battery tray; make sure that the terminals do not short against any metal during the installation.
24. Install the battery hold-down retainer, locking the battery into the battery tray. Install and tighten the hold-down retainer nut and screw.
Tighten

Tighten the battery hold-down retainer to 9 N·m (80 lb in).

25. Install the positive battery cable first.
Tighten

Tighten the positive battery cable to 17 N·m (151 lb in).

26. Install the negative battery cable last.
Tighten

Tighten the negaitive battery cable to 17 N·m (151 lb in).

27. Install air induction system.

Important

It may be necessary to use a 2 mm thick shim between the forward mounting foot on the air cleaner assembly and the midrail.

28. Road test vehicle to verify that vibration has been repaired.

Parts Requirements

Claim Information

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

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer".  They are written to inform these 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 your GM dealer for information on whether your vehicle may benefit from the information.

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