AD with T5 Requires Crossmember?

[Gippetto]

Need an opinion regarding weather you need to support the rear of a T5 tranny behind a near stock 235. I read a contraversy, don't remember where. about some saying you don't need one unless you plan to drag race or tow something. Others were more conservative and say it is necessary.
Any first hand experience out there?

[mr48chev]

I'd think that while you don't "need" one to bolt it in there it might be nice to have the support at the back of the trans. Not a total necessity but a bit of added support never hurts. I'd rig it so it was easily removable though. I've had to do both side of the road trans repairs and side of the road clutch repairs (actually parking lot) and being able to pull the trans easily was a lot of help.

That said I ran an aluminum case M-21 Muncie in my 48 for several years with no rear support and no problems.

[agnes the dog]

I had the same question a while back. I never really got a definitive answer, but the consensus was that it's better to have one than not. I really think that it's going to depend on how you set it up when you install it. I installed a Camaro T5 back in March and used the stock cast steel bellhousing. I had the Camaro (and a spare S-10) aluminum bellhousing too, but decided to use the stronger one. I put it in and decided that I couldn't wait to drive it before I made my cross member, so I drove it for a couple months without a cross member and had no problems at all. I got to feeling a little like I might be pressing my luck, so I went ahead and fabbed one and stuck it in. It was really easy once I figured out the 18* twist issue and it looks nice. With all that said, I wouldn't have trusted the aluminum bellhousings without a rear cross member. For me, having a cross member was just cheap insurance. I'm working on my post for how I made mine. Should be done today or tomorrow.

[dwcsr]

I would not use a rear mount. The frames flex so much it would put a lot of strain on the case and tail housing. A front mount, Bell mount and rear trans mount on a very flexible frame makes for a busted something for sure.

[Gippetto]

Thank's to all for the replies. I was leaning towards running without one thinking about what I would use to actually couple the trans mounting surface to the crossmember. It would need a rubber, complient mount and the question then would be how complient. You don't want to bind movement and put the loads on the case that you are trying to isolate. You would be chasing your tail, if you follow my thinking.

[mknittle]

I agree with Dave.
Maybe with a boxed frame and a single point mount would be OK. What do you think?

[agnes the dog]

Here's what mine looks like. I used the stock rubber mount.

[mechanixman]

Originally Posted by dwcsr

I would not use a rear mount. The frames flex so much it would put a lot of strain on the case and tail housing. A front mount, Bell mount and rear trans mount on a very flexible frame makes for a busted something for sure.

Now what if you only used the front mount and the rear trans mounts?

[dwcsr]

There may be a tremendous amount of strain in the mid section with no center support. 235's weight 600 lbs dressed with bell and clutch. I suppose it depends on what the T5 was in prior and what bell it has. But again there is no side mount on most AD 235's so it would flop over without the bell mount. Maybe if you used a rubber rear mount and not a real stiff aftermarket one it may have enough flex it compensate. The AD bell mount it nearly solid to the frame so it goes as that section of frame goes and not necessarily as the forward and rear sections go. I agree boxing would help. I know people have done it so maybe we can find one that's run it for a year or 3 and see what they say.

If the 235 has side mounts (58 and later did) then you could fab side mounts and do away with the front and center mount and use a rear mount. That would isolate the engine/trans from the frame flex.

[mknittle]

I forgot about the older engines not having side mounts. I have been working on a 250 that has them

Man it's always something Oh well back to a dodge 2x4 to 4x4 conversion

[magicoolbus]

I am planning on doing the t-5 swap very soon. I have accumulated everything I need except for time. I am currently running a 235 with a SM465. The 465 has provisions for a crossmember and I have been running without one for 15 years. I am also still running a two piece driveshaft as my truck is a long bed. (dunno if the short bed was 1 piece) I plan to swap to a one piece shaft when I make the swap.

[AZ59apacheguy]

Originally Posted by magicoolbus

I am planning on doing the t-5 swap very soon. I have accumulated everything I need except for time. I am currently running a 235 with a SM465. The 465 has provisions for a crossmember and I have been running without one for 15 years. I am also still running a two piece driveshaft as my truck is a long bed. (dunno if the short bed was 1 piece) I plan to swap to a one piece shaft when I make the swap.

I talked to the T5 just the other day. He said if you have a two piece driveline, or a long bed, that somekind of support should be considered. I'm not using any support or crossmember bar for my T5 in my '59 3100.

[Wrenchbender Ret]

The big heavy cast iron trans work fine without a rear mount but I sure wouldn't do that to that long thin aluminum one.

[mechanixman]

Originally Posted by dwcsr

There may be a tremendous amount of strain in the mid section with no center support. 235's weight 600 lbs dressed with bell and clutch. I suppose it depends on what the T5 was in prior and what bell it has.

I forgot to mention I'm running a 1968 327 sbc

[nvrdone]

I've been running a 327 & M21 in my truck for 35 + years. It's set up using the front side mounts into the frame with boxing plates from the front cross member to the rear spring mounts on the front spring. Then a single mount under the tail shaft of the trans, thus creating a 3 point triangle mount system. I do have the cross member under the bell housing. The only problem I had was popping the left motor mount due to lots of torque.
other than that, the design has worked well all these years.
I had a mechanic tell me that if I put mounts from the bell housing to the cross member, creating a 5 point system, something would break. I guess he was right.

[_Ogre]

i've driven out of the gravel pit many times with a ton of crushed stone in granny gear
never once worried about the trans breaking, the brakes yes, trans no
if your running stock front and bell housing mounts, i wouldn't worry about it
you'd probably add stress to the trans by using the stock mounts and adding a third mount