C3 - Body Mount Replacement

[Jim Markevitch]

My 72 coupe needs new body mounts as three of the rear mounting bolts are broke.
I found an article in the December, 2001, issue of Vette magazine on how to do this WITHOUT removing the body.

The gist of it is, you jack the car up, remove the nuts and bolts on one side of the car, brace the body so it is stationary and lower the frame just enough to remove and install the new hardware. The weight of the car will separate the body and frame just enough to allow you install the new components.

My question is, has any one used this method to replace the frame mounts? It sounds tricky but if a person is careful it should work. It sure beats spending $3,500 to remove the body.

[Harmon C.]

Re: C3 - Body Mount Replacement

If you have three bolts broken then you will probably have other things. that need done to replace the mounts. Nut cages on the frame,#4 sheet metal and nut cage,and rusted out holes at #2-3 body sheet metal all may need fixed and you won't know till your past the point to turn back . The method you are talking about sounds like it would work but I think I would raise the body not drop the frame. Dropping the frame and having something slip would be bad. Whatever you do be safe.

[Bill B.]

Re: C3 - Body Mount Replacement

Jim, we are at the same point on my son's 72 convertible except we will be lifting body on his. As I recall, I believe we could have replaced the #4 mounts by jacking just enough to lift body or lower frame to be able to slip the new mount on. The #4 mount on ours had about a 1/2" spacer that once removed gave us a fair start. It seems that you would need a separation of at least 3/4" or 1" to be able to slip the new mount in. The real problem that I see is that you have a single rearward rivet which you will only be able to peen by cutting a small access hole in the back side of the wheelwell fiberglass and loosening your other body mounts enough so that you are not stressing other points. Even as a convertible without the roof support his car did not want to flex enough to move significantly. In our case the #3 mounts were a bear to loosen and we had to cut one of the bolt heads off as it was so rusted. The other #3 was pretty easy. Like all repairs, once you make the hugh effort to get to it the actual fix is a piece of cake.

I still have an extra new #4 mount if you need just one. I will have to check and see which side it is for if you are interested. The part came from corvette central. you can contact me at dpswmb@peoplepc.com bill Belton, Tx

[Bill B.]

Re: C3 - Body Mount Replacement

Lyle has an excellent point--you do reach a point of no returning as you probably will find additional forward problems--maybe not. For example, the nut cages, another body mount bolt that cannot be removed, other hidden nut cages that cannot be repaired without a significant lift (#3 on frame), rusted out sill extensions and sills--you get it, just keep moving forward! We even replaced his windshield frame and that kind of tip off should clue all in about other repairs. Might as well jump completely in the water just know that it will probably be uncomfortable for awhile. Best of Luck.