The Stovebolt Site Forums The Shop Area Driveline Driveshaft length.

I'm putting a T-5 out of a 92 S-10 into my 56 3100 half ton. Will probably use a 82 camaro 3:42 rear. Anybody else done this swap and know what length the driveshaft needs to be? The rear will be installed over the leaf springs. The T-5 is 27 inches from the front of the trans to the center line of the universal joint with about an inch of play on the yoke. Any responses welcome.

The best advice that I can give you is to install the transmission and rear end, then measure to see what length you will need the driveshaft to be.
There are too many variables for anyone to know the answer to your question.
What is the ratio for 5th gear for your T-5?
With a 3.42 rear end gear, you won't be spending much time in 5th gear.unless you are running 25 inch tires.
I would recommend 3.73 or 4.10 with stock height tires.

27 inches? You lost me on that one. Mine was 53.25" from a T5 to a 12 bolt Chevy from a 1969 pickup. I used DSI...http://www.driveshaftspecialist.com/ Really good guys to work with and they'll give you an Army/Navy/Marine discount if you qualify. An inch to inch and a half of play ought to be good.

The best advice is going to be to have a driveshaft made for you. This way you will get it made the right length, you'll get a new transmission yoke, and you'll get it balanced. There's a world of benefit to a balanced driveshaft and constant misery from an unbalanced one...at any speed over about 40 mph it can be really bad. Here's what I'd suggest about measuring:
1. have the truck completely assembled...bed, bed wood, gate, spare tire, everything.
2. do not have it jacked up...have it sitting on the garage floor or driveway.
3. set your pinion angle. This is important. Read about it if you're uncertain.
4. slide under and measure from the end of the T5 housing (not the seal but the area just outside the seal) to the flat part of the u-joint mount (which coincidentally will be the center line of the u-joint. This is the measurement the driveshaft shop will probably want you to give them.

Good luck.

The driveshaft maker will want the measurements from ujoint center to ujoint center. As Jon suggested get everything in place then take your measurements. I’m assuming it will be that way on a T5. 🛠

Make sure your truck is in the usual loaded condition, too.

Ed

I drew up the driveshaft maker the most perfectly clear diagram for my last build. I didn’t have a yoke (I figured they would want to choose the one for whatever joints they had) it was a normal gm 27 spline like TH350. So I couldn’t give them a u-joint center to center. But i did give them a illustration picture clearly stating from rear end flange to the tip of the output shaft was like 24”. So they made me a drive shaft that was like 2” too long. I asked the place how they thought a 26” or longer shaft would fit in between two fixed pieces 24” apart. They were like “uhhhh we can just shorten it”.

I ended up blowing it into pieces a year later anyways hahahaha. That was a loud bang.

Martin, when I was talking to various driveshaft companies, when I mentioned T5, none of them wanted to make a shaft without including the new yoke. DSI (the folks I used) said I could ship them my used yoke which they would inspect and use but unless I did that and they used a new u-joint and balanced the whole she-bang there was no guarantee on the shaft.

Roger that. I supplied a new yoke when I did the 700R4 in my ‘62. I drew a diagram with measurements and the driveshaft company said they wished every customer would do it that way. BTW, in my neck of the woods driveshafts are not overly expensive.🛠

Barnfind, at least it was too long and could be shortened. Lengthening is not an option.

Ed

It is an option, but not a cheap one. The yokes can be welded on a new piece of tubing, hopefully of the right length.

That is making a new one.

Ed

It may have self lengthened itself when it blew apart under the car hahaha. The passenger had a rather startled look on his face. Over 700ft lbs with a touch of wheel hop and the rear joint let loose and it actually opened up the ears on the shaft and proceeded to beat the floor and ground while i was probably still on the rev limiter laughing 😆

I used a driveshaft out of a late 90's gmc safari van,long wheel base. Used a cross over ujoint to fit it to diff out of a 4x4 78 suburban. Direct swap in,no fabrication needed. 54 3100 235 t5 trans.

Not the same truck, but for my '53 1/2 ton T5 swap I used a stock Astro Van shaft and an S10 yoke. Other than having it balanced and using a crossover U joint to fit my '61 Chevy rear end I made no modifications and it was a perfect fit.

thanks