A Guide to the Automatic Transmission Mount for the 1971-1978 Oldsmobile Cutlass Supreme
Eliminate clunking noises and excess vibration by choosing the right transmission mount for your classic Cutlass.
- Common failure symptoms include clunking when shifting, cabin vibrations, and visible engine movement.
- It is highly recommended to replace the two engine mounts at the same time as the transmission mount.
- Choose a standard rubber mount (Anchor, DEA) for a stock ride or a polyurethane mount (Prothane) for performance, but expect more vibration.
- This is a straightforward DIY replacement that can be done in about an hour with basic tools.
Symptoms of a Failing Transmission Mount
When the transmission mount on your Cutlass Supreme wears out, the signs are hard to ignore. Because the part's job is to secure the transmission, a failed mount will allow for excessive movement, leading to distinct symptoms.
- Clunking or Banging Noises: The most common symptom is a loud "clunk" or "thud" when you shift the car into gear, especially from Park to Reverse or Drive. You may also hear these noises during hard acceleration or braking as the transmission shifts and bumps against the chassis.
- Excessive Vibration: A new mount is designed to absorb vibration, so a failed one will do the opposite. You may feel a noticeable increase in vibration through the floor, seats, or even the steering wheel, particularly when the car is idling in gear.
- Visible Movement: A quick visual check can confirm a bad mount. With the parking brake set firmly and the car chocked, have a helper briefly put the car in gear while holding the brake. If you see the engine and transmission assembly lift or rock excessively, the mount has likely failed. You may also see visible cracks, tears, or separation in the rubber part of the mount. 🎬 Watch this guide to diagnosing a bad motor or transmission mount.
Is it Safe to Drive with a Bad Transmission Mount?
You can drive the vehicle, but it is not recommended for extended periods. A failed mount puts extra stress on the engine mounts, and allows for movement that can damage other components like the exhaust system, cooling hoses, and driveshaft U-joints. It is best to replace it as soon as symptoms appear.
Choosing the Right Aftermarket Mount
Since new OEM GM mounts for this era are no longer available, the market consists entirely of aftermarket replacements. They fall into a few distinct categories based on your needs, from stock replacement to high-performance.
Brand Tiers for Your Cutlass Supreme
Good - Standard Replacement:
Brands like Anchor, DEA, Westar, and Pioneer offer direct, factory-style rubber replacements. They are the most affordable option and are designed to restore the original ride quality and comfort. These are a good choice for a stock, daily-driven, or weekend cruiser. While they are budget-friendly, online forums show mixed reviews regarding their long-term durability compared to the original parts.
Better - Heavy-Duty Performance:
Brands like Lakewood offer heavy-duty mounts designed for muscle cars and mild performance applications. These often use a more durable rubber compound and stronger steel to better control drivetrain movement, making them a good upgrade for cars with more horsepower than stock.
Best - Performance Polyurethane:
Prothane is a leading brand for polyurethane mounts. Polyurethane is a much stronger and more durable material than rubber, and it is highly resistant to oil and other contaminants. This type of mount offers the best drivetrain control for high-performance and racing applications. The trade-off is a noticeable increase in noise and vibration transmitted into the cabin, as polyurethane does not absorb vibrations as well as soft rubber.
Pro Tip: Replace Mounts in Sets
Your Cutlass has two engine mounts and one transmission mount. All three are made of similar rubber and have been subjected to the same age and stress. It is highly recommended to replace the engine mounts at the same time as the transmission mount. A single new mount will put additional stress on the remaining old mounts, causing them to fail sooner.
🎬 See a full DIY walkthrough for replacing engine and transmission mounts.Cost of Replacing Your Transmission Mount
The cost to replace the transmission mount on a 1971-1978 Cutlass Supreme is relatively low. The part itself is inexpensive, and the labor is straightforward.
| Item | Estimated Cost |
|---|---|
| New Aftermarket Mount (Standard Rubber) | $9 - $20 |
| New Aftermarket Mount (Polyurethane) | $25 - $35 |
| Shop Labor | $90 - $180 |
| Total Estimated Cost (At a Shop) | $99 - $215 |
Frequently Asked Questions (FAQ)
Can I replace the transmission mount myself?
Yes, this is a very feasible DIY job for someone with basic tools and a floor jack. The process involves supporting the transmission with the jack and a block of wood, removing the crossmember bolts, jacking the transmission up slightly, and swapping the mount. The entire job can typically be done in about an hour.
What's the difference between a rubber and polyurethane mount?
Rubber mounts, like the original, provide a smooth, quiet ride by absorbing vibrations effectively. They are ideal for stock vehicles. Polyurethane mounts are much stiffer and more durable, designed for performance applications to reduce drivetrain movement. However, they transmit significantly more vibration and noise into the car.
How do I know if it's the transmission mount or engine mounts that are bad?
The symptoms are very similar and often related. A clunk when shifting into gear is a classic sign of a bad transmission mount. A bad driver-side engine mount will often cause the engine to lift noticeably when you rev it in Park. Because they all wear out together, if one is bad, the others are likely weak and should be replaced as a set.
Are there any recalls for the transmission mount on my Cutlass?
No, there are no specific recalls or technical service bulletins (TSBs) from the NHTSA for the transmission mount on the 1971-1978 Oldsmobile Cutlass Supreme. A major GM recall in 1971 involved engine mounts, but it was a separate issue and part. This is considered a standard wear-and-tear component.
Helpful Videos
Technical Specifications
Common aftermarket part numbers include Anchor 2360 and Prothane 7-1604. Always verify fitment for your specific year and transmission combination.
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.
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Symptoms of a Failing Transmission Mount
- Is it Safe to Drive with a Bad Transmission Mount?
- Choosing the Right Aftermarket Mount
- Brand Tiers for Your Cutlass Supreme
- Pro Tip: Replace Mounts in Sets
- Cost of Replacing Your Transmission Mount
- Frequently Asked Questions (FAQ)
- 🎟️ Get 5% Off