A Guide to the Automatic Transmission Mount for the 1995-2005 Chevrolet Blazer
If you're hearing a clunk or feeling a vibration when you accelerate, your Blazer's transmission mount might be the culprit.
- This guide is for the 1995-2005 S-10 Blazer, as the 2007-2011 Blazer was not sold in North America.
- Key symptoms of failure are clunking noises when shifting and new vibrations felt inside the truck.
- For most owners, a standard aftermarket rubber mount from a brand like Anchor, Westar, or DEA is a very cost-effective solution.
- Replacing a bad mount is a simple, inexpensive repair that can prevent damage to more costly drivetrain components.
Is Your Blazer's Transmission Mount Failing?
On an older truck like the second-generation S-10 Blazer, the original rubber transmission mount has likely spent years getting hard, cracked, or soaked with oil. When the rubber fails, the transmission can move and shake more than it should. This leads to noticeable problems you can feel and hear while driving.
Symptoms of a Bad Transmission Mount
A failing transmission mount will give you clear warning signs. Here’s what to look for:
- Clunking or Banging Noises: The most common symptom is a loud "clunk" or "bang" when you shift gears (especially from Park to Drive or Reverse), accelerate hard, or brake suddenly. This is the sound of the transmission lifting and hitting the floor pan or crossmember.
- Excessive Vibration: When the rubber insulator wears out, it can no longer absorb drivetrain vibrations. You may feel a new, persistent vibration in the floor, seats, or steering wheel, which often gets worse during acceleration.
- Drivetrain Movement: In severe cases, you might feel the entire engine and transmission assembly lurch or shift when you step on the gas. A helper can often see the engine and transmission move excessively if they watch while you briefly shift the truck into gear with the brake held firmly.
Don't Ignore a Bad Mount
Continuing to drive with a completely failed transmission mount is not recommended. The excessive movement can put extra stress on other expensive parts, including the engine mounts, U-joints, driveshaft, and exhaust system, leading to more costly repairs down the road.
Choosing the Right Aftermarket Mount
For the 1995-2005 Blazer, you have a few good options. Since there are no known recalls or TSBs for this part, failure is typically due to age and wear.
Tier 1: Standard Aftermarket (Good)
Brands like Anchor, DEA/Marmon, Westar, and Duralast offer direct-fit replacements that are very affordable. For a daily driven Blazer, these mounts will restore performance and get rid of the clunks and vibrations. While some online forum users have reported inconsistent quality or shorter lifespans with budget brands, many others use them without issue. Given the low cost, they are a practical choice for most owners.
Tier 2: OEM (Better)
AC Delco is the original equipment manufacturer for GM. An OEM mount will provide the exact fit and rubber density your truck was designed for, ensuring optimal vibration absorption and a long service life. While more expensive than standard aftermarket options, it's the benchmark for quality and durability.
Tier 3: Performance Polyurethane (Specialty)
Brands like Energy Suspension offer mounts made from polyurethane instead of rubber. These are extremely durable and designed for performance applications, like off-roading or engine swaps, as they control torque much better than rubber. The major trade-off is a significant increase in cabin vibration, as polyurethane is much stiffer and does not absorb vibrations as well as rubber. This is a great choice for a dedicated trail rig, but not ideal for a comfortable daily driver.
Pro Tip: Check Your Engine Mounts Too
The transmission mount works together with the two engine mounts to support the drivetrain. If your transmission mount has failed, there's a good chance your engine mounts are also worn out. It's a good idea to inspect them at the same time and replace them as a set if needed for the best results.
Cost to Replace a 1995-2005 Blazer Transmission Mount
| Part/Service | Estimated Cost |
|---|---|
| New Aftermarket Mount | $10 - $30 |
| New OEM (AC Delco) Mount | $120 - $170 |
| Shop Labor | $60 - $100 |
| Total Estimated Cost (Shop) | $70 - $270 |
Cost estimates are based on national averages and may vary by location and specific vehicle configuration (2WD vs 4WD).
Frequently Asked Questions (FAQ)
Is it hard to replace a Blazer transmission mount myself?
No, this is a job most DIY mechanics can handle. The process involves supporting the transmission with a jack and a block of wood, unbolting the crossmember, and then unbolting the mount itself. Access to the bolts can be a little tight, but it typically does not require specialized tools.
Should I use a rubber or polyurethane mount?
For most owners, a standard rubber mount is the best choice for a smooth, quiet ride. If you use your Blazer for heavy off-roading or have a high-performance engine, a polyurethane mount offers superior durability but will make the ride noticeably harsher.
What's the difference between 2WD and 4WD mounts?
The mounts for 2WD and 4WD models often have different part numbers and are not always interchangeable. Always verify that the part you are ordering is correct for your specific drivetrain configuration before purchasing.
Can a bad transmission mount cause other problems?
Yes. If left unfixed, the excess movement can damage U-joints, driveshaft components, engine mounts, and even cause the cooling fan to hit the fan shroud. Replacing it promptly is a small repair that can prevent much larger ones.
Technical Specifications
OEM Part Numbers: 15767858
The mount consists of a steel frame with a molded rubber insert designed to bolt to the transmission and the frame's crossmember. Different parts are often used for 2WD and 4WD models.
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.
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