The Stovebolt Site Forums The Shop Area Paint and Body Shop Front fender to cab gaskets?

I purchased a set of gaskets for the front fenders where they bolt to the cab. They are very thick rubber and seem to be causing the fenders to bend out at the top a little bit, and deform the flange on the fenders as well... is this normal? Should those gaskets be something thin like paper?

I’ve been traveling for a month but am headed home this week to try to deal with this. Any input appreciated. Thank you.

How does the fender fit without the gaskets? The gaskets are anti-squeak, so they need to be somewhat thick. How thick are they?

Without seeing the issue, it’s tough to diagnose the problem but I do have a couple of ideas.

If when mounting the fender, if you have to bend the back or front of the fender back or forward to get some holes to align, it may cause the flange to bend in or out.

If the fender is replacement, you may need to tweak it a bit by either enlarging some holes or bending the flange to to get a better fit.

The holes line up, it’s just that the gasket is so thick that tightening the hardware causes the flanges to compress only near the holes, deforming the flange on the fender᠁.the Parker is rubber and probably 1/8 thick. I have no idea what the factory put in there, only that the assembly manual shows a gasket there. I feel like it should be paper, just like the other fender to inner fender gaskets᠁

I installed the molded gaskets I purchased from Chevs of the 40's and they were very close to the same thickness as the rubber gaskets that were between the fenders and cab when I removed the fenders. I had a similar problem but maybe not as severe as you describe. I used larger diameter washers to help spread the load and it seemed to work out ok. I might suggest that you back off the torque so as to not compress the rubber as much.

You could always use Nylock type of nuts so you can control how tight you want the assemblies.

If you are talking about where the rear of the front fender bolts to the side cowl, that is supposed to be beaded fender welting. It comes in a long roll, enough for both fenders, and comes with no holes in it. Am I missing something about the question asked?

52Carl, you've made an interesting point. The FAM provides a part number 3685575 in Section 11, sheet 9 for the 3100, 3600, 3800, 4000- 6000 models. That number superceded to 609725 which is what you said, 2 1/4" x 100 foot roll , one bead. Chev's of the 40"s sells a part number 609725 which appears to be "molded " as it is the shape of the fender to cowl joint and has holes at the correct spacing and size. Its about 1/8 thick but has no "bead". It sure sounds like what I've purchased is not the same as what GM used and may be thicker than its supposed to be. Can you estimate about how thick it should be? Thanks for getting into this discussion. Your input could be a big help to Norcal Dave and me.

The beaded fender welting is just under 1/16" thick where it goes between the sheet metal. The bead is 1/4" in diameter. Plenty big to hide any gaps in this inherently problematic area. In my opinion, this welting design was used in this area for that very reason.

A whole lot of folks don't like beaded welting. That's been discussed here plenty. If you want to make yourself some excellent anti-squeak gaskets, go to a plumbing supply store and purchase a foot of 1/16 shower pan liner...very tough stuff. It will be 6 feet wide and that's more than enough. Make templates from old file folders and use those to cut your pieces. Paint them black if you wish, but in the AD truck it isn't necessary. They'll last about 1 week past the end of time. Good luck.

Thanks 52Carl and Jon G , looks like the gaskets I installed are the "wrong stuff". Wish I'd dug into the material specs a bit more before I purchased and installed those. Thanks to you both for your input. Hmmm, how hard could it be to loosed those fenders and replace them? Right?