The Stovebolt Site Forums The Shop Area Driveline Does A T5 Behind A 235 in an AD Need A Tansmission X-Member?

Lots of searching and a lot of differing opinion. Let's see some more? A member would be easy enough to weld up but is it necessary?

What year truck?

From 1954 onwards a transmission cross-member was not needed, unless it was a Hydra-Matic transmission (much heavier than a T5). The rear motor mount frame cross-member changed in 1954.

I used the factory crossmember with the T-5 in my 46 as it was just about in the right place, moved it back just a few inches.

I used the factory cross member on my 37, also. The transmission mount itself hit right middle of the cross member at it's stock location with just enough room for the mounting (shock absorbing) pad.

Hope you appreciate this reply, it's the fourth time I've had to
retype it since the site keeps requiring me to log in multiple
times, which is getting real old and I may just have to go the
way of Virgil Cain if it keeps up.
Assuming you haven't further re-engineered your 'AD', the six
cylinder engine is supported by a somewhat ridged three point
mount. The larger trucks that came standard with the four speed
transmissions didn't have a rear cross member. The 150lb. SM420
just hung from the four bolts attaching it to the clutch housing.
Your typical T5 is about half the weight at somewhere close to
75lbs, so you figure it out.
The main reason the 3100 had the crossmember was for an anchor
point for the support it gave to the front of the torque tube.

Denny Graham
Sandwich, IL

I got educated on this back in 2008 here on The Stovebolt: https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=451242&page=1

What I learned was from an engineering and stress consideration you ideally only want 2 support locations on the engine / transmission assembly. (front and bell housing -or- front and transmission)

If the engine already has the front and bell housing supports then the transmission should not have the support.

If you are of the opinion that the transmission needs to have a support you should eliminate the bell housing support location.

I did not install a transmission cross member on my '65 C10 that runs a M-21 Muncie 4-speed car transmission and have had no problems with it.

I always put a crossmember with a mount under the rear of a T-5. That skinny aluminum trans should not be hanging out with out support. The factory had 4 braces on them.

Not a truck, but my 55 210 Chevy has a Muncie 4 speed with no cross member. I'm pulling about 485 HP and about the same numbers in torque, and I've been beating the crap out out of it for years.
No problems.

Brian

And here there are more conflicting opinions!

I cut up and reboxed the stock trans member last night just in case I need it. It fits only a few inches form the stock location with the T5.

Crossmember

You can see the stock T5 rusty mount hanging in the box I cut for it. Just need to find a way to extend the bolt from it out the bottom hole.

Just my 2 cents, looking at your picture, it seems you already have supports at the bellhousing and maybe one at the front of the engine.
You got to have some movement for torque. Seems adding a support at the tranny could cause it to take the load and crack the case.
Probably better without one.
Note the 2-point comment in the above post.
The vehicle that tranny was in, probably only had one support on each side of the engine, therefore the tranny mount created the 2-point system.

I think you and John are correct. I fabbed that member last night before I read anything here and just to see how it fit.

But the T5 mount is rubber w/ 2 contact points on the T5 and then just one to the x-member. I certainly seems designed to allow for some play and movement.