TH400 Mount

I am removing my transmission for a rebuild and i noticed that the tranny mount is going to need to be replaced, it looks like it is split completely in half with a large section missing.

I am wondering where i can get the mount (TH400 in a 1969 Wildcat) and if there are any variations which one is best for a high power application.

thanks

 

On top of that ill add these questions:

Has anyone used Royal Purple Tranny Fluid? Is it worth it?

Also, has anyone gotten a replacement gear set for their transmission, i was looking at TCI's low gears for the TH400 (2.75 first, 1.57 second) and was wondering if anyone has an opinion either way, and if they think this gearset would work with 800 hp (just to be safe)

thanks

 

Buy a poly mount from Energy suspension.

 

Just use a good quality trans fluid, no autozone brand, walmart ect.

 

i second the poly mount
can get at summitracing
i ran that gearset in my 400 until i broke the trans case
when my driveshaft ripped in pieces(stocker)
real good launches and still have some top end
you wont need a really big rear gear and still get some mpg
should handle 800 hp but you might want to find out for sure

 

There are so many different kinds of mounts, i guess ill have to take mine off and measure it to see which one it is.

did you lose any top end with that gearset, it doesnt say the 3rd gear so im assuming its still 1:1.

thanks

 

yes 3rd is still 1:1
the poly mounts should be the same for most years you will just change the stud to bolt as the poly has 3 bolt holes

 

ok, thanks for the info.

 

Synthetic tran fluid is the only thing anyone should be using in an old valuable transmission like a turbo 400. Like modern motor oil modern trans fluid has been de-engineered as modern transmission run cooler so the new stuff is crap. Unless you are willing to change trans fluid every year then use synthetic. Worth every penny

 

how about royal purple?

(im pretty sure its synthetic?)

or Lucas?

thanks

 

Royal Purple is high quality. I have been using Mobil ! synthetic trans fluid for several years. Trans guy I know took my trans apart recently when I had it out just to check out and said it looked like new. Was rebuilt about 30K ago. Changing fluid every other year never hurts either.

 

Ok, sounds like a plan.

will be much easier once i get a deep pan with a drain plug also.

thanks

When i took my tranny out i didnt even have to unbolt the mount, it was seperated (big time).

So now i need to measure it up and get one that will replace it.

 

well, since my mount is seperated (picture of crossmember mounting part attached) i can only measure the bolt spacing, which is 4.25 wth 3/8" bolts.

The holes are diagonal though, all the mounts i can find are straight, so im thinking of buying one and drilling new holes in my crossmember.

The Gm style mount im looking at has that same width (for the transmission side), and straight crossmember mounts instead of horizontal, easy fix, but it is about 2" tall (1 and 15/16 inches).

Will this height pose any problems if installed in this car?

thanks

 

should be fine that should be stock highth
the holes in your crossmember should be slotted so unless something was bent you should be fine