W107 Subframe mounts

The Mercedes Benz 107 series uses a separate front subframe.   The engine and front suspension attach to the subframe, and then the subframe attaches to the body.   The subframe uses rubber mounts (very similar to motor mounts) to isolate noise, vibration and other harshness from the driver.    The subframe itself was basically lifted from the W114 series.    It wasn’t really up to the job with the larger and heavier engines of the 107 series and there was a recall to strengthen the lower control arm mounting points.

Over time, the W107 subframe mounts collapse in just the same way as motor mounts do.   This causes sloppy handling as well as vibration coming through the body of the car.   I have been chasing a grinding noise and feeling from the car on acceleration.   I recently changed the drive-shaft centre support, which didn’t help.    Later, when jacking up the car I noticed how collapsed the subframe mounts looked.

W107 Subframe mountsI wasn’t planning to do this work, but I did want to source the parts.    There are a few different suppliers for this part, but I had heard that the aftermarket mounts from the likes of Febi don’t hold up very long.   The genuine Mercedes mounts are still available, but with the rate parts are becoming No Longer Available (NLA) for the youngtimers, I figured it was worth getting the genuine parts while I could.   If the genuine parts went out of production or went to silly money, I would have taken Febi over Meyle.

You used to be able to buy a kit of all the parts needed.   For some reason Mercedes-Benz have discontinued that part number (115-330-18-75) even though all the parts are still available individually.   The aftermarket suppliers haven’t so if you buy aftermarket you can still just buy the kit.

Part #DescriptionQuantity
115-333-02-65Rubber Buffer4
912004-010102Lock Washer4
115-331-03-46Stop Buffer4
107-330-02-75Sub-Frame Rubber Mount4

Most of the cost is the actual W107 subframe mounts, two per side.   Those are the last item on the list with the 107 part number.   As can be seen in the photo, the new one looks a lot better.

W107 Subframe mountsAfter driving the car a few times, there is a noticeable improvement.   The last time I drove the car before the change, the handling was all over the place.   The new mounts have tightened that up and the grinding noise is gone.   I saw the old ones when they came out, and they were down to metal in a few places.  These photos are also the last before I cleaned out the wheel wells in my cars to show off the original paint underneath the years of grime.

The handling is still not perfect.   There is a decent amount of play in the steering at the centre position.   I had the steering box re-sealed but I don’t think the hard parts are available for right hand drive anymore.

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