I had my driveshaft modified and shortened. It was a small block auto driveshaft which I had shortened, a heavy duty yoke attached and then balanced.

I hope I'm overlooking a simple installation trick or get a measurement from someone with a T5 in their car, because I can't figure out how to install thge driveshaft. There seems to be no way to get it up in the frame and slide the yoke in the end of the tranny. If I remove the yoke it might go out of balance and can it even be re-installed on the driveshaft while in the car?

I did a search and saw a post about a special yoke (by Keisler?)to make driveshaft removal and installation easier, should I consider this as well?

Thanks as allways for the input...

 

My T5 installation was quite simple enough. Initally I mounted the tranny to a bare engine block and installed it in the car to fabricate trans mounts. Once that was done, I was able to measure how much my driveshaft would need to be shortened. Come installation day, I attached the driveshaft to the rear end and then installed the trans, sliding the yoke spline of the driveshaft, into the trans. The bellhousing, clutch fork, and TO bearing was already installed on the trans. I used some wood blocks to support the bell housing. and had the trans mount bolts in but loose. Then I installed the engine. Now after everything is back together, servicing the driveshaft would be very difficult, as it would be in any C3.

 

You need to install the front U joint after the shaft is installed into the car.

First slightly enlarged the yoke cap holes so that the caps press into the yoke with just a little pressure.

Then install the yoke in the trans alone(without U joint installed)

Install the drive shaft in the car and press the caps into the yoke. I can do my caps with just slight taps with a small hammer. Make sure the retainer clips are in properly.

 

With the driveshaft installed, the yoke hits the tunnel on the passenger side. I had found a good thread on driveshaft installations, and will use a protractor triangle to measure the tranny, pinion and driveshaft angles.

If they are correct I guess I'll have to cut the tunnel to make clearance.

If they are not I guess I have a huge problem. The car had been hit, and allthough there was no frame repair, and the frame measures out, the motor mounts were never plumbed (and neither was the tranny mount because I have yet to permanently weld it in place as I wanted the drivshaft in before completing the welds)

Could the motor mount positions be off enough to skew the tranny angle and effect the fitment of the driveshaft in the tunnel? If so, do I need to use frame-straightening techniques to fix it?

I'm concerned as since starting the finishing work on this car nothing has fit, from S&P polished alternator brackets (two now not aligning properly), the lokar throttle cable and even the keystone front bumper.

This thing is fighting me all the way, will it ever run???

 

When I installed mine it was off to one side as well, I was not hitting the tunnel though? I loosened off the motor mounts and the tranny mount, with them all loose you can pull the tranny one way or the other. There is some play there. As far as installing the drive shaft with the body on you have to make sure that the front yoke is an easy fit so you can assemble it in place, as you can see there is not much room there. Mine is close to my Emergency brake cable / pulley, you may want to check that as well.

Good luck

 

Auto TH350 C3 drive shaft should have a take apart trans yoke, I bought one for my T5 install

 

Hello, I know this is an old post but, can you tell me what length you cut your driveshaft?

 

Considering that poster was last here in 2014, I doubt they will be answering your question.....

 

I’m hoping someone else knows, at least the thread gets renewed when someone comments. Hopefully another member will be able to help. Can’t seam to find out how much to cut this drive shaft to make this gm t5 work. If anyone sees this please chime in. Thanks!

 

You would have to have it installed then measure it. I think tremec has a video on how to measure. Or you could ask the company that is going to cut and balance it

 

That’s very helpful. I am going to do just that . Thanks! Does anyone who has done a t5 swap remember what the cut ended up being at the end? Just out of curiosity..

 

Hey Floridavetteguy,

I can measure my driveshaft length for you this evening. Car is up on stands while I'm rebuilding the motor. I did the T5 swap last year, but can't remember the exact length I had the driveshaft cut to. I believe it was cut 2.5" shorter (29.5" total maybe?). But I'll double check. What year is you car? My is an 80 with the Aluminum dana rear end. Not sure if there is a difference between the length of the rear end input between dana and the eaton, but there may be a little. So you definitely want to measure for yourself.

To install, you have to separate the yoke from the driveshaft. Which is easy for the auto cars because the ujoint is secured with straps not pressed. So install the driveshaft on the rear ujoint, slide the yoke all the way into the transmission, swing the driveshaft into place and pull the yoke out to mate up to it. If you don't have them, I also highly recommend getting the spicer u joint strap kits that have the the smaller 6 point hex. Makes installation (and later removal) MUCH easier.

Just make sure when you measure for the driveshaft length that you pull the yoke out of the transmission about an 1 inch to allow for movement under normal driving conditions. This allows allows the driveshaft to be installed.

Lastly, if you haven't done so already, figure out your speedo gears. Most of the T5's came with the blue drive gear. With my 3.08 rear, I needed a red drive gear because I couldn't get the right combo with the available driven gears. At the time I just wanted to the project to be done so left the blue drive gear and picked the closest driven gear, but my speedo was still over 10mph off. So while the motor was at the machine shop this winter I also pulled the T5 back on and swapped the drive gear in the tranny to red. So now everything should be good. But I wish I would have just taken the extra day to pull the tailshaft off and make the swap from the beginning.

 

dang trevor that is some seriously good info, my c3 is a ‘73, I’m going to have to take the measurements, bc my car is a 4 spd, I am assuming the measurements will be different from an auto. Thanks for the install tip too. I will have to change the gear for the Speedo, now that you told me that I won’t wait on that and will do it when the transmission gets here on Wednesday. Did you use a gm t5 or a Ford? I am using a gm mounted straight into the existing Muncie bell housing. Thanks!

 

I am doing the same on a 79 manual. I am intending to use my existing bell housing and clutch linkage. The yoke on my drive shaft has clamps so it is easy to remove. I thought I would measure the two gearboxes and however much longer the T5 is I would take of the drive shaft length. My only concern is the cross member, since my Vette was a stick shift the cross member is welded in. I have seen members ask if the T5 can be fitted without cutting the cross member but nobody ever gives a straight answer. I guess once I try to fit mine I will know.

 

what im finding Is that people were doing this over 10 years ago on these forums and a lot of people don’t remember exact measurements and specifics on things like the crossmember bracket. These are things that are made
on the spot. I’ve seen some threads where there are pictures of exact measurements but all the pics are taken down. A lot of pics are taken down here about t5 swaps. My inner conspiracy theorist thinks the Keisler and American powertrain folks have influence on this forum and are silencing swap info, but of course that’s silly and probably not the case. Just keep searching the forums and copying and pasting good info.A lot of what is being done seams like you have to come up with solutions on your own. These threads get refreshed when people like us search and quote them. Hopefully more folks chime in. This swap can seam daunting, I am at the stage where I bought everything and now I’m about to measure where driveshaft sits so I can put it back in the same spot. Lots more work to go.
since I’m a noob I cant really answer your questions either but maybe someone else will know the answer.

Threads can veer off too like I probably just did to you so: does anyone know if a crossmember absolutely has to be cut to install a t5 either mounted sideways or straight up? Is there anyway to avoid cutting the crossmember?
(I apologize if there already a thread for this)

 

I have a Mcleod Muscle car 5 speed which is a modified T5 and the shifter got jambed in between the floor and the crossmember while installing it with it attached to the motor. If you take the shifter out it may just clear. I was able to cut the crossmember out and weld on flanges without burning the car down but I have some new scars to prove I did it. While welding I draped an old burn resistant welding blacket over the crossmember but the blanket was resistant, not proof. Theres some major differences between the 2 trannys so I dont think I can help much

 

Alright, I was way off on the measurement I previously posted. My driveshaft measured 25 inches from center to center of the ujoints.

I used a GM T5 with the Camaro tilted bellhousing.

In terms of the crossmember being removable, I was very lucky to start with an auto. My gut tells it would be a huge PIA if not impossible to install the trans with the crossmember in place. I don't think you could move the transmission far enough back for the bellhousing to and input shaft to clear the pressure plate. But I can't say for sure.

 

I know this answer was done 5 year ago, but you still remeber how much you shortened the drive shaft? Did your method of measuring both transmissions work? I'm exactly doing the same as you.
I have a 1980 with manual transmission and swapping for a t5 wc from a camaro 1992, using my old bell housing.

That info will be super useful!

Some other questions, was it necessary to expand the shifter hole at the tunnel?
what about the speedo gear?

Thank you,
Adel

 

I am just swapping out my 4 speed in a 1979 to a 5 speed WC. The 5 speed is 2 3/8” longer than the 4 speed. I measured both from bell housing flange to rear face of the gearbox output shaft casting. I intend to have my drive shaft shortened by 2 3/8” to 2 1/2”. Not had it done yet but hopefully will be dropping it off next week. Does anyone disagree with this approach. Inputs welcome.
“ what about the speedo gear?“ I am informed that a 21 tooth is required for my car which has a 3.7:1 rear differential.

 

Go to www.tciauto.com , then to “Automatic Transmission Dimensions”. You’ll find Chevy trans down the list. I think you can make a decision based on that information of what length to remove from driveshaft length.