I converted my 65 over from a c-4 to a early 90's T5 a couple of years ago. I retained the orginal c-4 drive shaft and yoke. The car barely was driven when I decided to tear it down to the skin and go for a more complete restomoding. Now things are going back together with 5.0 and 9 inch rear end that had I built up for me. I went ahead and stuck that old c4 driveshaft and yoke back in and it all buckles up nicely. There is still about an inch of play. I was snooping around the web last night looking for a backup light pigtail for the T5 when I came across this from the Sacramento Mustang web site under T5 conversion.

The T5 does require a different yoke. Some of the original yokes will fit into the tail shaft. As tempting as it is, don't use it. The older yokes do share the same spline however the T5 yoke is shorter and does not extend so deep into the tail housing. The longer yoke can damage the tail bushing by restricting the flow of oil down the shaft.

My question is are they just trying to sell the shorter yoke or do you really need it? I looked around more and found some guys are even cutting some of old yokes down. What say ye experts of the T5 swap?

 

Bumping this thread because I need to know too. Perhaps someone could give us the proper length of the yoke for a T5 and how much should be sticking out.

From what I understand we need about 1 inch of yoke extending clear of the seal to allow for suspension movement. I do not know a minimum or maximum of yoke inside the seal.

 

Pretty sure that's a load of horse crap...the outside diameter is the same for both shafts.

The bushing has flutes and pockets (looks like a golf ball with rifling down it) to allow oil to collect and flow through the bushing.

If you could slide the c4 yoke into the bushing by hand without cussing or breaking a sweat then it will be fine oil supply wise.

Yeah the t5 yoke is shorter but that will NOT effect oil flow to the bushing.

-Gun

 

As for end play past the end of the tailshaft I am still undecided as to how precise it must be. let just say this: if you have a oil-seal with the dust cover the yoke should just about touch the end of the dust cover. As in actually rubbing on the dustcover or 1/32" inch away from it would be the very best possible outcome.

I'm going to say you may run the risk of high-speed vibration if the yoke does not just slightly touch the end of the dust cover.

If you have a non dustcover oil seal then shoot for 0.90" clearance between end of tailshaft and the very end of the yoke tube.

-Gun

 

I was involves in trying out the first T5 adapters (before they were released to the public), and the trans was installed with the 67 OEM slip yoke already on the car. This was in the early 90's. The car was sold last year, with that slip yoke still in there.

 

I have one of the long yokes in my T5 and it is fine. The spline count is the same and the seal has no gaps. If you take a T5 apart the only thing you would hit with a really long yoke would be the speedo gear and that is WAY away the end of the tail shaft end.

 

I performed the same conversion on my 65' (from a C4 to a T5) and retained the C4 slip yoke. No problems here at all.....

 

Having .750 to 1.000 inches of free play is more important than which yoke you use.
Here are pics of the 2 types of slip yokes so everyone can see the differences.

 

Oh yeah might as well mention now that even if the t5 yoke was the solution to everyone's problem it's not going to fit your drive shaft

You need to either throw away your original DS and get a nice 3" tube with 1310 style U joints to fit the t5 yoke

OR

get the adapter U joint setup that allows you to run the old DS with the new t5 style yoke..........

-Gun

 

I used the Street or Track aluminum DS with the a 1310 to 1330 U-joint.
It is vibration free up to 90. Have not gone faster than that...
More info here:
http://chris66dad.tripod.com/id34.html

Good Luck and Be safe