Guide to the 1987-1991 Jeep Wrangler YJ Automatic Transmission Mount
Stop drivetrain clunks and excessive vibrations by choosing the right transmission mount for your YJ.
- A clunking noise on acceleration is the most common sign of a failed mount on a YJ.
- Choose a polyurethane mount (Prothane, Daystar) for durability and off-road use, but expect more cabin vibration.
- Choose a standard rubber mount (Anchor, DEA) for a smoother, stock-like ride on a daily driver.
- Always inspect your engine mounts when replacing the transmission mount, as they wear out together.
Is Your YJ's Transmission Mount Failing?
The transmission mount on the YJ Wrangler is a simple part, but it takes a lot of abuse. Over time, the rubber can crack, collapse, or completely separate from the metal plates. This is especially common on Jeeps that see off-road use or have been exposed to oil and heat for many years. When it fails, you'll definitely notice it.
Key Symptoms of a Bad Mount:
- Clunking or Banging Noises: The most common sign is a loud "clunk" or "bonk" sound when you accelerate, brake hard, or shift between Drive and Reverse. This is the sound of the transmission physically moving and hitting the skid plate or frame.
- Excessive Vibration: If you feel new or worsening vibrations in the cabin, especially while idling or accelerating, the mount's rubber may no longer be absorbing the drivetrain's vibrations.
- Shifter Movement: You might see the transfer case shifter handle move excessively when you get on and off the gas. This is a direct sign that the entire transmission and transfer case assembly is rocking back and forth.
A Completely Failed Mount
In severe cases, the mount can break in two pieces. When this happens, the transmission is no longer properly supported, which can put extreme stress on your engine mounts, driveshafts, and exhaust system. It's a failure you'll want to address immediately.
Choosing the Right Aftermarket Mount: Rubber vs. Polyurethane
For the YJ Wrangler, you have two main choices for aftermarket mounts: standard rubber (OEM-style) and polyurethane (poly). Neither is universally "better"; the right choice depends on how you use your Jeep.
Standard Rubber Mounts
These are designed to be direct replacements for the factory mount. They provide the best vibration isolation, resulting in a smoother, quieter ride that's closer to stock. For a daily driver or a Jeep that sees only light off-roading, a quality rubber mount is often the best choice.
- Brands like Anchor, DEA, and Pioneer offer affordable OEM-style rubber mounts. Forum discussions suggest that while they are a budget-friendly option, their longevity can sometimes be a concern compared to OEM or performance brands.
Polyurethane (Poly) Mounts
Polyurethane is a much stiffer material than rubber. This makes it far more durable and resistant to oil, heat, and grime. Poly mounts are excellent for off-road and performance applications because they significantly reduce drivetrain movement, providing a more connected feel. The main trade-off is a noticeable increase in vibrations felt inside the Jeep.
- Brands like Prothane, Daystar, and Rugged Ridge are popular choices for polyurethane upgrades. They are built to handle the extra stress of larger tires and heavy off-road use.
Pro Tip: Inspect Your Engine Mounts
When you replace your transmission mount, it's the perfect time to inspect your engine mounts. If the transmission mount has failed, it has likely put extra stress on the engine mounts, and they may be worn or broken as well. Replacing them at the same time can save you from doing a similar job twice.
Aftermarket Transmission Mount Cost (1987-1991 Jeep Wrangler YJ)
| Part Type | Typical Price Range | Notes |
|---|---|---|
| Aftermarket Rubber Mount (e.g., Anchor, DEA) | $18 - $25 | Best for stock-like ride quality and daily driving. |
| Aftermarket Polyurethane Mount (e.g., Prothane, Daystar) | $25 - $35 | Best for durability, off-roading, and performance. Expect more vibration. |
Frequently Asked Questions (FAQ)
Is it hard to replace a YJ transmission mount?
No, it's a relatively straightforward job for a DIY mechanic. The process involves supporting the transmission with a jack, unbolting and removing the transmission skid plate, unbolting the old mount from the transmission, and then installing the new one. The most common difficulty is dealing with rusted bolts on the skid plate.
Do I need special tools to replace the mount?
You'll need basic hand tools like a socket set and wrenches (typically 13mm and 15mm sizes), a floor jack, and jack stands. An impact wrench can be very helpful for removing stubborn skid plate bolts.
My Jeep is lifted. Does that change anything?
If your Jeep has a suspension lift, you might already have a transfer case drop kit installed, which uses spacers between the frame and the skid plate. This doesn't change the mount replacement process, but it's something to be aware of when you're removing and reinstalling the skid plate. A bad mount can worsen existing driveline vibrations on a lifted Jeep.
Are there any recalls for the 1987-1991 Wrangler transmission mount?
No, searches of the NHTSA database did not find any recalls or technical service bulletins (TSBs) specifically related to the transmission mount for the 1987-1991 Jeep Wrangler YJ. Recalls found were for different model years or different transmission components.
Technical Specifications
OEM Part Numbers: 52002542 52002625 52019386
The mount bolts to the transmission housing and the central skid plate, supporting the rear of the powertrain. It consists of a rubber or polyurethane block vulcanized to metal mounting plates.
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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.
- Jeep Wrangler:
- 🛍️ Shop This Part
- Is Your YJ's Transmission Mount Failing?
- Key Symptoms of a Bad Mount:
- A Completely Failed Mount
- Choosing the Right Aftermarket Mount: Rubber vs. Polyurethane
- Standard Rubber Mounts
- Polyurethane (Poly) Mounts
- Pro Tip: Inspect Your Engine Mounts
- Aftermarket Transmission Mount Cost (1987-1991 Jeep Wrangler YJ)
- Frequently Asked Questions (FAQ)
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