Service note, rear suspension on a CMC built "roller" chassis

Last update: 6/26/08 Return to home page links

My car
had been occasionally making some loud crashing noises in the rear end (particularly the right side) as I let up and gave the car gas. One day I was working with the bolts in the forward end of the rear suspension links and found that the upper bolt was not clamping Heim joint tightly enough in the bracket.

The 3" long hardened bolts that CMC used to clamp the Heim joint links in the brackets on the rear suspension on my car are just a little too long. Many bolts that long aren't threaded the whole length.

When CMC stuck the bolts through the brackets holding the 2 spacers and the Heim joint the non-threaded part of the bolt was flush with the outside edge of the brackets. When they/I screwed the nut on it barely tightened all the pieces together as the nut came up onto the non-threaded portion of the bolts. In affect the Heim joints weren't fully clamped in place even though the nuts seemed tight enough.

As I was driving the car and gave the car gas and let up, the rear end linkage was crashing back and forth inside the brackets!

I made up four 1/4" thick "washers" from some aluminum stock, put them between the nut on the four brackets and torqued the bolts to 60 ft-lbs. No more of those noises from the rear end now!

I'd suggest that if you have a CMC car with the 3" long suspension bolts holding the rear linkage together that you check if the nuts have really tightened the pieces together properly.

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