1966-1970 Oldsmobile 98 Automatic Transmission Mount Replacement Guide
Address clunking noises and excessive vibrations by understanding how to choose and replace the transmission mount on your classic Oldsmobile 98.
- Symptoms of failure include clunking noises when shifting and excessive vibration at idle.
- Aftermarket is the only practical option; the available Anchor brand has mixed reviews regarding quality and potential for increased vibration.
- Replacement is a straightforward DIY job for this vehicle, requiring basic tools and a floor jack.
- Failure to replace a bad mount can lead to damage to engine mounts, the driveshaft, and exhaust components.
Symptoms of a Failing Transmission Mount
A worn-out transmission mount on a classic, heavy car like the Oldsmobile 98 will produce noticeable symptoms. Because the original rubber has likely degraded over 50+ years, failure is common. Look for these signs:
- Excessive Vibration: You may feel a new or increased vibration throughout the car, especially when idling in gear or accelerating. This happens because the worn rubber can no longer absorb the vibrations from the engine and transmission.
- Clunking or Banging Noises: Loud clunks or thumps when you shift from park into drive or reverse are a classic sign of a bad mount. You might also hear these noises during hard acceleration or braking as the transmission shifts and hits the frame.
- Drivetrain Movement: An experienced mechanic can often see the engine and transmission assembly move excessively when shifting gears with the brakes applied. In severe cases, a failed mount can cause the fan to hit the fan shroud.
Choosing the Right Aftermarket Mount
For a vehicle from this era, finding a New Old Stock (NOS) OEM transmission mount is nearly impossible and would be very expensive. The primary option for your Oldsmobile 98 is a new aftermarket part.
Brand Quality: Anchor
Anchor is the most widely available aftermarket brand for this part. As a budget-friendly option, owner experiences are mixed. Some classic car owners report that Anchor mounts fit well and work without issue for years. However, other owners have reported issues with inconsistent quality. Common complaints include the rubber being harder than the original, which can transmit more vibration into the cabin, and premature failure where the rubber cracks or separates. Given the low price, it is the most practical choice, but be aware that its performance and longevity may not match the original GM part.
Estimated Replacement Costs
| Part Type | Part Cost | Shop Labor Cost | Total Estimated Cost |
|---|---|---|---|
| New Aftermarket (Anchor) | $14.17 | $150 - $250 | $165 - $265 |
| New OEM (NOS) | Not Generally Available | $150 - $250 | N/A |
Pro Tip: When replacing the transmission mount, it's a good time to inspect your engine mounts. These three mounts work together as a system. If one has failed due to age, the others are likely worn as well.
Frequently Asked Questions (FAQ)
How can I visually inspect my transmission mount?
Safely raise the vehicle on jack stands. Locate the mount at the rear of the transmission where it bolts to a metal crossmember. Look for visible cracks, tearing, or separation in the rubber. You can also use a pry bar to gently check for excessive movement between the transmission tailshaft housing and the crossmember; there should be very little play.
Is it difficult to replace the transmission mount on a 1966-1970 Olds 98?
For a rear-wheel-drive car like the Olds 98, this is a relatively simple job for a DIYer with the right tools. The process involves supporting the transmission with a floor jack and a block of wood, removing the bolts holding the mount to the crossmember and transmission, and installing the new part. It typically does not require specialized tools.
What happens if I don't replace a bad transmission mount?
Continuing to drive with a failed mount puts extra stress on the engine mounts, exhaust system, and driveshaft U-joints. In severe cases, the misalignment can cause shifting problems or damage to other components, leading to more expensive repairs down the road.
Why does my car vibrate more with the new aftermarket mount?
This can be a common issue with some budget-friendly aftermarket mounts. The rubber compound used may be harder than the original factory part, causing it to absorb fewer vibrations and transmit more of them into the car's frame and cabin. While the mount is structurally sound, the ride comfort may be reduced.
Technical Specifications
Height: 1.80 inches. Compatible with 1965-1967 Oldsmobile 98 7.0L V8 and 1968-1970 Oldsmobile 98 7.5L V8.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.