Im going to be putting an S4 TII trans into my 85 gs. It has a gslse rear end. What driveshaft will i need? Or will I need a TII drive-shaft to go into the trans and then have to get a custom shaft made from both? thanks!

 

It needs to be a custom driveshaft with the T2 slip yoke on the front and the FB flange on the back, its also slightly shorter than a FB driveshaft, though not by much.

 

sweet thanks!

 

In my album you'll find the measurements/diagram for a driveshaft used with the TII tranny.

 

Actually all you need is the yolk from a second gen with an automatic. The yolk is the same as a TII but the u-joints are the same as the 84-91 NA 5-speed cars. You can get a replacement u-joint from Rockford Driveline (part # 430-10A) for about $30.

 

I've heard of this before - but never straight from someone who has done it. It has always been, "a friend of a friend did it this way, etc"

So let me get this straight as I want to archive this.
Please correct me if I am wrong. You solution sure sounds better than spending $400 on a custom drive-shaft as I did.

In your car - you have:

1) Turbo II Tranny (what series?)
2) Stock 83 Rear end
3) Stock 83 Driveshaft
4) Stock TII Front Yolk
5) Replacement u-joint from Rockford Driveline (part # 430-10A)
mounted on the front u-joint?

I thought some of the FB drive-shafts
had u-joints that were supposedly not serviceable/replaceable?

My mind is blanking out.

 

yes i would like to know this for sure as well thanks

 

From what I understand, the S1 and S2 (maybe just S2) has replaceable u-joints. Replaceable as in the "normal" way with those stupid spring clips that hold them in place. However, I have read many times on here by those who have done it that the S3 shafts CAN BE replaced but you have to PRESS OUT the OEM ones and then replace them with the ones mentioned. No idea if they need machining of a groove or not. I dont have a S3 drive shaft handy or I would look at it closer.

Edit: Should say that although I own an 83 I swapped in an 82 diff and drive shaft, which is why I cant look at one.

 

I'm assuming he will reply, but he's saying you need the front yoke from an Automatic FC (not the T2 yoke) and then you simply put that on a S3 driveshaft using the U-joint he specified.

I could have sworn the T2 swap driveshaft I am using is a hair shorter than a FB stock shaft, however it wasn't much... If this does actually work then I'm going on the hunt for a Auto yoke and keep it as a spare in case my custom driveshaft ever gives me trouble

Both S4 and S5 T2 transmissions are the same length and have the same output shaft spline size/count so that doesn't matter.

 

S1/S2 driveshafts are indeed rebuildable. I've done a few.

S3 driveshafts are NOY rebuildable. The U-joints are staked in place, and the area where the circlip would normally go is not machined to spec. I have had rebuilt S3 driveshafts and the U-joints were off-center enough that they vibrated terribly, even though they had been balanced after U-joint replacement. As an experiment, I took one, removed the circlips, chucked it in a lathe, and centered the U-joints - the mismatch was too far for a simple cleanup machining operation to handle - it was .060" off on one of the yokes!

Now, it is entirely possible that SOME S3 driveshafts have the tolerances stacked so that you can pop in a S1/S2 U-joint (it's the same part) and it will be centered enough to work well. Local drivshaft shops won't bother trying to rebuild one, though, they will just assemble a new one and charge you $500. But at least they use real U-joints, and decent sized tube, and not the tiny U-joints and soda straw driveshaft that will suffer a harmonic at about 85mph...

You also have to be VERY CAREFUL with pressing in the new U-joint cups. It's easy to wallow out a hole and have a cup that is less than a press fit.

 

The U-joints can be replaced in any driveshaft. If anyone would have taken the time to actually research Rockford Driveline, you would find that the replacements for the Staked in joints have the retainer clips on the inside. Anywho, the parts needed are:

1=83 1/2 - 85 large pinion flange driveshaft.
1=86-91 automatic driveshaft.
1=U-joint from Rockford Driveline-http://rockforddriveline.com/replacem.htm

Remove the yolks from both driveshafts. Use the automatic yolk on the first gen gen driveshaft with the new u-joint.

Simple enough?

 

Yes, the clips go on the inside. However, the yokes are not machined precisely for those clips. They did not need to be since they were not being used for locating the U-joints.

You may get lucky and have a driveshaft where they were machined reasonably centered and will give you no problems. The rebuilt driveshafts I had were not such beasts, the U-joints were not centered.

At 60mph the driveshaft is turning 4000rpm. You can feel .010" offset in a U-joint. Again, one of mine was off by .060", meaning the center was .060" different. Chuck it in the lathe and the difference between high and low spots was nearly .120".

The PROPER way to rebuild them would be to hold the U-joints centered and re-stake them, or invent some other way to hold them in place. Most people don't have the equipment for this. I don't anymore either. Fortunately, I can still find good used driveshafts for ~$50 or so, and I have one or two non-nonrebuildable driveshafts and diff yokes set aside for when that supply dries up.

Fortunately, I'm not going through one or two driveshafts a year anymore. Not using 4.78 gears anymore helps a lot. So does paying extremely close attention to pinion angle.

 

Im going to do exactly this... got both driveshafts and will be ordering u joint next paycheck (if i have enough after paying a ticket) Thanks!! hope this works as smoothly as you say

 

I currently have this set up in my car right now check my sig...

GSL-SE rear end with a 1995 kia sportage welded diff that has 4.78 gears rx7 rear mounted flange, measure to cut shaft, with 5.0 mustang yoke...Yes i said mustang yoke...mazda, kia and ford run inter changable parts thats why somebody bought somebody out i don't wtf happen but this **** works...

Also using the mustang yoke, it has refillable bleeder valves...

but yes there a few ways you can go about doing this...My shaft in the end ran me $300 cut and balanced and looking great..

Wackyracer, ultimatejay and few others are just a few to name that you could ask for help...but this set up is not to hard...

 

shouldn't need any cutting welding or balancing with what im doing.. will cost about 50 bucks... thats very cool tho!

 

GREAT info!

 

I'm doing the same exact thing you are doing. I talked to bad83 and should have my driveshaft done soon. Worrying about other things first.

 

orderd my u-joint today.. they guy at rockford driveline was a really nice guy on the phone.. should have the u joint monday... then making 2 shafts one!!!

 

im doing the same setup but have:

I have a 79 Sa, turbo II motor, Turbo II tranny (shortened the shifter location), 85 GSLSE rear end (flange drilled for both drive shafts) also have a respeed engine mount so I can move the motor up or back if needed. With this adjustment and by the shortened shifter location I should be able to keep the shifter in the same area with out cutting the body. Then to measure and have a custom shaft made even though I have a 79 stock shaft and a factory TII shaft that I could make into one.

 

So, I was about to order a u joint and then realized If I have the aftermarket driveshaft from mazdatrix with replaceable u joints and my driveshafts for 83-85 cars I can just re-use the u joint from my driveshaft. All I need is the yolk.

 

I agree with everything said above. 7's aren't the only cars with the nylon staked u-joints either. Yes you can stuff an inside clip joint in, but they rarely center.

 

save your self the effort in the first place, it might be more $$$ up front, but will save you the money when the U joints go bad and when you break your diff (which a turbo car will, I know...)

buy a T2 drive shaft, have a shop put replacable U joints front and rear, have the shop also swap the rear flange on the driveshaft for one that matches the FB 3rd member your planning on using, then have the shop make it custom length to fit your car.

benefits are
-replaceable U joints
-never have to open up a 3rd member or change backlash setting when you remove the flange to put your T2 flange on the FB diff

 

Isn't the FB third member flange going to utilize the smaller u-joint which we're trying to avoid anyway?

Does the GSL-SE rear use a large u-joint? Seems like that rear with the TII setup is the way to go without going ford or something of the likes.

 

gslse rear has a larger flange not sure if its a larger u joint i can check... i have 3 rear ends at home and both now three driveshafts...

 

My 13bt FB has:

GSL-SE Rear
S4 Turbo II Trans
GSL-SE D/S
GSL-SE Rear Flange
S4 Automatic Front Yoke
Rockford Driveline 430-10A U-Joints

Total cost: $30 for joints and $50 for balancing.

Holds my race car with slicks and Raceport w/ 15lbs of boost