R107 Engine Mounts: Symptoms and Replacement

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R107 engine mounts are rubber, and after decades of heat and oil they sag or split. Worn mounts make the car vibrate, clunk, and let the engine move enough to stress hoses and linkages.

Symptoms of collapsed mounts

• Vibration through the steering wheel and seats at idle, especially in Drive
• A clunk when shifting from Park to Drive or Reverse
• The engine rocking visibly when someone blips the throttle
• The fan close to or touching the shroud
• Exhaust contacting the body or subframe

How to check

1. Open the hood, set the parking brake firmly and hold the brake pedal.
2. With a helper watching, shift into Drive and give a brief, light throttle. Then into Reverse.
3. Watch the engine: a lift of more than a small amount on one side points to a failed mount.
4. Look at the mounts with a flashlight for cracks, separated rubber or oil soaking.

Do this carefully, with nobody in front of the car.

Engine shock absorbers too

Many R107s have small engine shock absorbers (dampers) at the front of the engine that control movement. When they fail, idle vibration and the clunk on shifting get worse. They are inexpensive and often overlooked; replace them with the mounts.

Parts

Buy a pair of engine mounts, the transmission mount, and the engine dampers for your model. Quality matters: very cheap mounts often transmit more vibration. Check the part numbers for your engine.

Replacement steps

1. Support the engine from below with a jack and a wood block under the oil pan, or from above with a support bar.
2. Remove the nuts on one mount, raise the engine slightly, and swap the mount.
3. Lower and tighten to spec, then do the other side.
4. Replace the transmission mount by supporting the transmission.
5. Fit new dampers.

Watch the fan, hoses and throttle linkage as you lift the engine.

Cost

Parts are moderate. Labor is usually a few hours at a shop. Combined with a flex disc and transmission mount, it often transforms how refined the car feels.

Quick answers

• Do mounts cause overheating? Indirectly: a sagging engine can push the fan against the shroud.
• How long do mounts last? There is no fixed interval; on a 40-year-old car with original mounts, assume they are tired.
• Can I replace them without a lift? Yes, with good stands, a floor jack, and patience; access to the nuts is the slow part.
• Will new mounts reduce the vibration in Drive? If the old ones were collapsed, the difference is usually immediate. If vibration remains, check idle speed, misfires and the flex disc.