T5 trans swap question

[dhamilton62]

So for anyone that's done the T5 swap in their C10, did you guys fab up a rear support for the tail housing on the trans? I heard from some that if you have two mounting points on the bell housing already than a rear support isn't needed. I ran it without for a test drive and all the gears felt great until I went on the freeway in 5th and on de-acceleration, and coasting in 5th there was excessive vibration and noise until I put a load back on the truck. Could that be a caused from not having the tail supported from a frame brace? Thanks everyone.

[Wrenchbender Ret]

I have done several & always put a crossmember support on the rear of the trans. I could not stand to see that long skinny aluminum trans hanging out there by itself. I do not believe it will cause a vibration problem though. I have a vibration problem on the 56 pickup I have now with the T-5. I have been working on it for 6 months trying to figure what is causeing it.

[HumphreyMurdoch]

I put a T-5 in my Plymouth and my '62 and both are hanging out in the breeze without another crossmember. I haven't had any issues or vibration problems and they've been in for 6 years in my Plymouth and just one year in my truck but I'm not hot rodding or side stepping the clutch either. Just driving like an old geezer.

It wouldnt hurt to add one, I've thought about it.

Speedway sells universal crossmember with about any amount drop you'd need.

[Lugnutz65]

I'm in the middle of a T5 installation in my 1965 C10. So my thoughts are oriented torwards my setup with a cast iron bell and a bell cross member.

People debate whether having bell housing mounts AND T5 tail housing mounts is a good idea or not. To me, the engine torque will cause some movement of the bell. The rubber bell mounts allow for this movement. The T5 case and tail housing must be able to move as a unit with any bell movement. The S10 T5 tail housing bushing has a 2 hole mount and the rubber mounts to the frame with only 1 bolt so it will allow minor rotation caused by torque. As long as the tail housing is NOT more rigid than the bell, then having both should be OK. Just my opinion but necessarily fact.

I don't have a cross member installed in the photo, but I have all the pieces set aside to fabricate one. Just not time for it yet.

I have no criticism for folks who run the T5 without it. If someone has seen a failure (with or without) I sure hope they speak up.

[brokenspoke]

What pilot bushing did you use? The T-5 is metric and can cause a vibration if you used the original bushing

[wildearp]

I was wondering how people crack bell housings........

You have plenty of room for a rear support and it would take less than an hour to put one in. I have never seen someone run a trans unsupported.

[dhamilton62]

Originally Posted by brokenspoke

What pilot bushing did you use? The T-5 is metric and can cause a vibration if you used the original bushing

I believe I used the original bushing as it looked fine, but hearing what you said sounds about right. Do you think that would cause the trans and truck to shake more as the speed increases? I'm not sure it's RPM related as the truck is fine 1st-4th in a higher RPM, but just shakes in 5th and only when I let off the gas either coasting or going down a hill. Also thanks everyone for all your input and help and this weekend I'm fabbing up a trans crossmember!

[4mulaSvaliant]

One more thing to keep in mind. (I started to get hung up on the pilot bushing issues as well recently)

If you have a late model motor (I happen to) then the pilot bushing already in the motor may very well be the correct metric 15mm bushing / bearing for the T5.
I started looking for the bushing in the Astro Van clutch set I bought and there was NO bushing or bearing to be had. I started to look and locate one and realized I have an 86-ish 350 and it likely had the correct bushing. I mic'ed it out before installing and sure enough I had the correct bushing already.

[Lugnutz65]

Keep in mind that a Camaro T5 pilot bushing might be different than an S10 pilot bushing.

[gigolo258]

My 65 C10 had a Muncie M20 installed by the original owner in 1968 with no crossmember and hauled a camper every summer for years and drove it daily from new until he parked it in 1992 with no transmission problems at all.With that being said I still like the idea of a crossmember on Muncie and T5 installs.

[dieseldude4bt]

That T5 weighs nothing compaired to the 4speed that used to be there and it didn't need a crosmember why would the T5?

[Lugnutz65]

Originally Posted by dieseldude4bt

That T5 weighs nothing compaired to the 4speed that used to be there and it didn't need a crosmember why would the T5?

The factory transmissions were all cast iron and the T5 is aluminum. I think the "worry" is that the case or the ears will stress fracture. That's why I hope someone will volunteer info if they ever had a failure either with or without a cross member.

[dieseldude4bt]

It is less likely to fail by holding it's self up than it was originally holding it's self and the back of the engine.
But that's just my opinion.

[CRGRS 66]

TTT
I am interested to hear more opinion on this subject. I have a Camaro T5 with S10 tail shaft, and had no intention of adding a third mounting point for the engine/bell/trans assembly. I had read that the third mounting point could create opposing stresses. I also figured that the original 3 speed that weighed considerably more did not need any support, so why would the T5? I have no intention of driving mine like a teenager, but if the third xmember is needed, now is the time for me to deal with that as the cab is off right now.

[CRGRS 66]

Originally Posted by dieseldude4bt

It is less likely to fail by holding it's self up than it was originally holding it's self and the back of the engine.
But that's just my opinion.

Of course I didn't read this post all that carfully before I made my previous post.

Did the Camaros and S10's just have the engine mounts and the rear trans mount? If so, I have to agree with this opinion.

[Jim53066]

So far no one has answered the OP's question about the vibration issue he has.

I would think that if the vibration is only in one gear, (overdrive) like his is, it would be a bearing inside the transmission, or possibly ya drive shaft out of sinc or a U-joint?

If the lack of a cross member was the issue, I would think it would do it in all the gears.

Jim

[tlorber]

I had a T5 behind a 235 on my '54 and never had issues. However that is a low torque motor as compared with an SBC or a LS motor. I think it really matters what you have in front of the tranny.

[C-10cutty]

Originally Posted by dhamilton62

So for anyone that's done the T5 swap in their C10, did you guys fab up a rear support for the tail housing on the trans? I heard from some that if you have two mounting points on the bell housing already than a rear support isn't needed. I ran it without for a test drive and all the gears felt great until I went on the freeway in 5th and on de-acceleration, and coasting in 5th there was excessive vibration and noise until I put a load back on the truck. Could that be a caused from not having the tail supported from a frame brace? Thanks everyone.

I'm not running a support for the T-5 behind my 235 and it runs smoothly through all gears. Did you have the tranny gone through before mounting? I had mine freshened up before use. Keep us updated.

[4mulaSvaliant]

I would agree with Jim.
Unfortunately, you are going to just get a bunch of opinions rather than fact necessarily.
If I were to weigh in with thought to this, Id say it was either specifically 5th gear that gives you trouble, or the other instances I have had vibration on deceleration is from u-joint issues, or excessive slack in the rear dif gears.

I can attest to multiple mounts not being the best scenario. It is a fairly general rule in designing driven systems I.E. engine/trans, and what I commonly design around Motor/compressor, that too many points of mounting will cause stress points that are not needed. That is of course also based on the over all length and spread of the feet and the overall weight and stresses applied.

I recently did this swap (in the last few weeks) and have yet to drive my truck with it in, so I cant attest to any results. I also went with a single pc drive shaft and it may change the game a bit too.

Id guess at either u-joints, rear dif wear, pinion bearing, or possible 5th gear issues.
As for U-joints, either bad u-joints, mis-alignment of the yokes, or possibly the drive shaft needs to be re-balanced.

[Palf70Step]

Is anyone running something like this without the bellsousing mounts, just side engine mounts and tranny mount?

[Scot_Douglas]

Originally Posted by Palf70Step

Is anyone running something like this without the bellsousing mounts, just side engine mounts and tranny mount?

Yep! Certainly did, and with no problems (well - other than breaking the trans internally with too much HP).

[4mulaSvaliant]

Oh damn.... with the Vette rear too! Nice!!!

[CRGRS 66]

Originally Posted by dhamilton62

So for anyone that's done the T5 swap in their C10, did you guys fab up a rear support for the tail housing on the trans? I heard from some that if you have two mounting points on the bell housing already than a rear support isn't needed. I ran it without for a test drive and all the gears felt great until I went on the freeway in 5th and on de-acceleration, and coasting in 5th there was excessive vibration and noise until I put a load back on the truck. Could that be a caused from not having the tail supported from a frame brace? Thanks everyone.

If your drive shaft U joints are not new, you may want to start there. Is your truck lowered? Pinion angle may be the issue as it is only at highway speeds. Drive shaft out of balance could be an issue, did you shorten it yourself, or have it done at a shop?

[Scot_Douglas]

Originally Posted by 4mulaSvaliant

Oh damn.... with the Vette rear too! Nice!!!

I wish!
it's a T-bird SC 8.8" IRS

[4mulaSvaliant]

Very cool regardless! Sorry to hi-jack the thread. Ill hush now. Hahahaha