radiator support shim

[Bill Stephens]

I've seen in earlier discussion threads that both the sides and bottoms of a radiator support for a c3 (1969) small block can be shimmed. I think that the bottom of mine needs to be shimmed, but I can't find shims for the bottom mounting bolts at any of the regular vendors. They all only seem to sell shims for the sides, which are too small to fit the bottom bolts.

I believe that the bottoms need to be shimmed because the fan shroud sits too low and pinches the lower radiator hose. The previous owner cut a piece out of the shroud to accommodate the hose, but I've got a new shroud and want it to fit correctly. I don't know what happened to the old shims. They weren't there when I took it apart.

Thanks for your help.

[Jack H.]

Re: radiator support shim

Sometimes the catalog houses don't list parts that are still off-the-shelf from Chevy. Have you tried Mr. Goodwrench for PN 3952926 (it may be replaced by a functionally equivalte PN today) to see if the radiator support to frame shims are still available?

[Jim T.]

Re: radiator support shim

Might find some usable shims at body shop supply facilities or try NAPA, they could have catalogs you could see the pictures of shims and order them.

[Chuck S.]

Re: radiator support shim

Bill, the AIM shows shims at the radiator support bottom mounting bolts and between the inner fenders and the radiator support. The bottom shims are PN 3952926; according to the parts book, this shim is applicable to 69-72, and probably years following as well.

Actually, I don't think that shimming the bottom of the radiator support is going to fix your problem...if you raise the support, I believe you raise the shroud, BUT, the radiator is raised as well; nothing is gained.

Shimming the RH side of the radiator support would help my problem a lot, namely the fit of the hood to the front headlight panel and the fender sides...Without that, it seems I can get the hood to fit in some of the places, some of the time, but not all the places, all of the time. The AIM also shows shims under the hood hinges, but my car didn't have any, and there's no where to lower the hood at the hinge point if needed.

I have not found the bottom radiator support shims in reproduction, and I doubt they are available from GM (Maybe Joe can help us on this.) My car also had NO shims at the bottom OR the sides, and based on what I see on other cars, I don't think they were used much on the assembly line, if at all. that may explain why there are no reproductions available.

I have considered trying the earlier C2 shims, but first I'm going to see if there is enough slop in the frame extension horn on the right side to raise the cross member enough to fix my fit problems.

[Joe L.]

Re: radiator support shim

Bill------

Well, I can't find them in Dr. Rebuild's catalog WHICH THOROUGHLY AMAZES ME. They do show the C1 radiator support shims which, although similar in configuration, are not the same. However, Paragon does show them in their catalog. It's their item #8904. One buck, each.

[Bill Stephens]

Thanks everyone NM *NM*

[Bill Stephens]

Re: radiator support shim

Thanks Chuck. I do want to raise the entire assembly, shroud, radiator, and support. The lower hose is pinched between the shroud and frame. Raising the shroud, radiator, and support relative to the frame will do it I think. Good luck with yours.

[Chuck S.]

Re: radiator support shim

Well, cool, there they are at Paragon...those guys just keep introducing new products.

Hey Doc!...Better watch out; those foot steps behind you are getting closer! Ohhhhh, that's right!...The Doc is already sitting on the beach sipping ice tea! (Only kidding you, Doc...sitting on the beach IS GUUUD!)

[Joe L.]

Re: radiator support shim

Jack------

Yes, GM #3952926 were the shims originally used in PRODUCTION and once available in SERVICE. Unfortunately, SERVICE availability ended in July, 1985 when the GM #3952926 was discontinued without supercession.

[Chuck S.]

Re: radiator support shim

My mistake, I didn't remember the earlier thread correctly.

I would still try the frame extension horn first. I have a hunch there is some slop in the bolt holes...you may be able to get enough there to fix the problem. With either shims or the frame horn, you'll be raising the entire front end relative to the frame, so it may be advisable to back off the #1 and #2 body mounting bolts, and retorque them after you are satisfied with the adjustments. I would check the height of the front wheel opening to make sure it's close on both sides; you don't won't to leave the front end all whomper-jawed.

You'll need a hydraulic jack to raise that cross member because all the front end weight is on that cross member through the radiator support. Be advised: from my own experience, you may affect the hood fit...maybe for the better, if the right side of the cross member has always been abnormally low.

[Harmon C.]

Re: Thanks everyone NM

Bill

Be carefull jacking on the body because you could break the holes in the fiberglass holding any parts attached to the frame.

Lyle