View Full Version : TR2/3/3A TR3 Trans Cover gasket

04-30-2006, 10:52 AM
Hello, listers, I seem to recall a thread a while back, (which I can't find in search), about what to use in place of a gasket on TR3 trans covers. Something like insulation tape, open cell or closed cell? Looking at the Moss diagrams, nothing there either, although there is some kind of thick gaskety type material remaining in bits and pieces on my car.... Any BTDTs?

04-30-2006, 05:00 PM
Hi Kevin,

My local auto parts and hardware stores both carry all sorts of gasket materials. Why not just get a sheet of that and cut out a proper gasket? Take an old scrap from the gearbox as a sample, so you can get the proper type and thickness.

One way to make a gasket is to lay a sheet of the material on top of the trans (or whatever the gasket is being made to fit), tape it in place so it won't move, then tap all the edges lightly with a hammer. I use a nylon hammer for this. The tapping will at least make an impression of the gasket shape that will give you a guide with scissors, or, if the edges of the gearbox (or whatever) are sharp enough, the tapping might leave the sheet pretty well cut to shape already.

That just leaves the bolt holes. Years ago I bought a set of punches for this purpose and they work great. After the tapping process, you should have clear indications of all the bolt hole locations, too. An Xacto knife will work, too, but is fussier and takes longer.

It takes about as long to type this description as it would to make a gasket this way.

Once the gasket is made up, I like to use Hylomar to seal it up. The main reason for this is that the gearbox can be filled immediately and reinstalled, no waiting for sealer to cure and dry, prior to or after assembly. Another thing I really like about it is the nice, blue line it forms that helps visually shows that a good seal has been formed.

Unfortunately, Hylomar is now harder to find, since it's no longer being marketed in the U.S. by Permatex. But, I think they now have their own, similar product. Ask the folks at any auto parts store for a recommendation.

Note: I stay clear of RTV/silicone products and so-called "gasket makers" because any excess that accidentally squeezes out inside can chunk or flake off and get into the internals of the parts being assembled. This can block oil feeds and cause other problems.

Overall, with all types of gasket sealers many folks tend to use too much. Just a thin coat that's adequate to fill any flaws, scratches or impressions in the mating surfaces is all that's needed. Try to minimize squeeze-out.

Hope this helps.


04-30-2006, 08:12 PM
Thanks, Alan, for your always informative post! In the meantime, I wound up with 3/16 closed cell insulation. I chose it because it was closest to the bead of whatever sealing material was on there before. It worked great; I'm very happy with it, especially since it cost all of a $1.69 for a 10 foot roll at the local ACE hardware. Like you, I wanted to avoid silicone sealants; this worked out very well, in my experience. Thanks again!