So i broke the crossmember bushing recently and am going to replace all my tranny mounts this weekend. Crossmember+2 y blocks. So I got my new cross member in and was just inspecting it and such.

Then Noticed that there were air holes in the bushing where the rubber wasn't completely solid all the way around. Then I remember from my Honda days use to fill these holes with either RTV silicone Window Weld or epoxy to stiffen the mount and reduce wheel hop.

So I was thinking that it should work the same on any mount that has generally the same design. I've seen the mazdaspeed 3 guys do it to their stock motor mounts also.

But now my question is, will it be okay for the transmission cross member to be completely solid or does it need some room to flex?

For those who are unsure of what im talking about refer to this link.
http://www.mazdas247.com/forum/showthread.php?t=72087

any any added vibrations is not really a factor for me. as long as it helps reduce flex in the drivetrain

 

Good idea, but I dunno if any of that sticks to the existing rubber?
I would love to just fill that **** with polyurethane!
This goes the same for the rear diff upper mounts, since they are the same design too...


-Ted

 

I do that on my T2, but I have not driving it yet.

 

I heard theres a metal to rubber epoxy Im gonna stop by a local hardware store to look for it. and you use either a paper plate or some tape to hold the filler that you are using in place until it dries.

 

how about filling it with hot glue?

 

Its possible. but Im not sure about how good it would hold up to the elements. remember this is on a car so its gonna have to dirt, rain etc. And sometimes glue will harden up like glass and break.

But as long as you don't use anything to crazy like jb weld where it ends up like steel. Because I'm sure it needs a little bit of flex.

When I had my integra I found window sealer to give the best result. It withstood the elements, held up well, no cracking, and eliminated almost if not all the wheel hop. However the vibrations did increase but I didn't mind. But im still young and performance>comfort.

For a mod that was free I can't complain, just as good as paying 50 bucks motor mount inserts.

 

Window sealer?
Got a brand?
How about a pic of a link?
Sounds like silicone (RTV)?

I guess this would work a LOT better if the parts are new, huh.
My trans mount is SOAKED right now, so I doubt anything will stick to it.
I guess I'll order a new mount and mod that one before I put it in.
My trans bucks like a bitch in the cowgirl position on acceleration! :P


-Ted

 

Maybe a hockey puck or two could be shaved down to fit in there in place of the stock bushing to salvage old crossmembers.

 

If your going that far, just chuck up some urethane stock in a lathe.

 

I'm pretty sure that urethane is too soft to mill, it has to be moulded to its final shape. Things like Delrin can be milled because they're hard with almost no give at all. Besides, who has access to sticks of plastic and a lathe? Lots of people have access to hockey pucks and knives.

 

There are alot of sources for round stock (UHMW, Urethane, Delrin) online. A foot of UHMW rod stock is <$20. The urethane is kinda hard to work with depending on its hardness; the UHMW is very easy.
I drill the center and press in the pipe that the bolts will slide through. Then I chuck up the pipe in my haggard-*** mini lathe and go to town. It seems to minimize distortion enough to get a clean cut.

 

window weld from 3m is a pretty good one. Find it at most local hardware stores.

Yea and using it on a brand new mount would be the best to allow the material to bond to the rubber. Unless you can clean up your mount really good.

 

I used on mine window weld.