1966-1977 Ford Bronco Engine Mount Replacement and Diagnosis Guide
Stop excessive engine vibration and clunking noises by choosing and installing the right new motor mounts for your classic Bronco.
- Symptoms include clunking noises, heavy vibration, and visible engine lifting when applying throttle.
- Always replace engine mounts in pairs to ensure even support and longevity.
- The job is DIY-friendly using a floor jack and a block of wood to support the engine.
- Standard aftermarket brands are affordable but may have questionable longevity; heavy-duty mounts offer more durability for off-road use.
Is Your Bronco's Engine Mount Failing?
After 50+ years, the original rubber in your Bronco's motor mounts has likely seen better days. Heat, oil, and the torque from the engine cause the rubber to crack and separate. When a mount fails, the engine can move and shake excessively, causing noise and potential damage to other parts.
Common Symptoms of a Bad Mount:
- Excessive Vibration: You might feel a strong vibration in the steering wheel or through the floor, especially when idling.
- Clunking or Thudding Noises: Loud clunks when you accelerate, decelerate, or shift gears are a classic sign. This is the sound of the engine lifting and dropping back into place.
- Visible Engine Movement: Have a helper put the Bronco in gear, hold the brakes firmly, and gently apply the gas. If you see the engine lift up significantly (more than an inch or two), a mount has likely failed. The driver's side mount often fails first due to engine torque.
- Fan Impact: In severe cases, the engine can lift enough for the cooling fan to hit the fan shroud, causing a racket and damaging both parts.
Visual Inspection is Key
Look at your mounts. If you can see the rubber is cracked, separating from the metal plates, or soaked in oil, it's time for a replacement. Even if only one is visibly broken, it's best practice to replace them in pairs as the other has been under extra strain.
Choosing the Right Aftermarket Engine Mount
Original Ford (OEM) mounts for this generation of Bronco are generally no longer available new. The market today consists of standard aftermarket replacements and heavy-duty or performance options.
Standard Replacement Brands (Good/Better)
Brands like Anchor, DEA, Westar, and Pioneer are widely available and very affordable. They are considered economy or standard-grade replacements. For a stock daily driver or a budget-conscious restoration, these can be a viable option. However, online forums show mixed reviews regarding their long-term durability and fitment, with some owners having to replace them again after only a few years. Some enthusiasts seek out New Old Stock (NOS) American-made Anchor mounts, believing their quality to be superior to modern versions.
Heavy-Duty & Performance Mounts (Best)
For Broncos used for off-roading or those with modified engines, heavy-duty mounts are a popular upgrade. These often use polyurethane instead of rubber and may feature a safer design with a through-bolt that prevents total separation even if the material fails. While much more durable, be aware that polyurethane is stiffer than rubber and will transmit more engine vibration into the cabin. Some heavy-duty mounts may also be slightly taller than stock, which can sometimes cause minor alignment issues.
For most owners, a quality standard replacement is sufficient. If you use your Bronco for heavy off-roading or have a high-torque engine, investing in heavy-duty mounts is cheap insurance against future failures.
Engine Mount Replacement Cost
Replacing engine mounts is a budget-friendly job, especially if you do it yourself. The parts are inexpensive, and the labor is straightforward for a professional mechanic.
| Item | Estimated Cost |
|---|---|
| New Aftermarket Mounts (Pair) | $15 - $110 |
| Shop Labor | $150 - $300 |
| Total Professional Replacement | $165 - $410 |
Frequently Asked Questions (FAQ)
Can I replace just one engine mount?
You can, but it is not recommended. Engine mounts wear out together. When one fails, the other has been subjected to extra stress and is likely weak as well. Replacing them in pairs ensures stability and saves you from doing the job again soon.
Is it hard to replace engine mounts on a 1966-1977 Bronco?
No, it is a relatively easy DIY job for someone with basic mechanic's tools. You need a good jack, jack stands, and a block of wood to support the engine. The process involves supporting the engine, unbolting the old mounts, lifting the engine slightly, and swapping in the new parts.
Do I need an engine hoist?
An engine hoist (cherry picker) is a great way to do the job, but it's not required. Most people use a floor jack with a piece of wood placed under the oil pan to spread the load and safely lift the engine just enough to get the mounts out.
What is the difference between V8 and 6-cylinder mounts?
The mounts for the inline-six (170ci/200ci) and the V8 (289ci/302ci) engines are different parts. Be sure to order the correct mounts for the engine in your specific Bronco.
My new mounts don't seem to line up perfectly. What should I do?
This can sometimes happen. Try leaving all bolts loose until both mounts are in place. You may also need to loosen the transmission crossmember bolts to allow the entire drivetrain to shift slightly for better alignment. Once everything is aligned, tighten all bolts to the manufacturer's specifications.
Technical Specifications
Mounts are specific to the engine type (inline-6 or V8). They consist of two steel plates bonded by rubber. Improved aftermarket designs may include a safety through-pin or be made of polyurethane.
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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.
- 🛍️ Shop This Part
- Is Your Bronco's Engine Mount Failing?
- Common Symptoms of a Bad Mount:
- Visual Inspection is Key
- Choosing the Right Aftermarket Engine Mount
- Standard Replacement Brands (Good/Better)
- Heavy-Duty & Performance Mounts (Best)
- Engine Mount Replacement Cost
- Frequently Asked Questions (FAQ)
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