Vibrating Driveshaft Question
 

Hi All,

I'm in a bit of a pickle. I've got a non turbo car with a turbo II tranny and a non turbo rear end. the drive shaft is vibrating at about 60 mph - which I've read is probably a bad u-joint.

The problem is that I have no idea what I need to replace given the hybrid nature of everything. How do I know if I have a turbo II or N/A drive shaft? I assume it is the N/A shaft with a T2 u joint. So in my head I should just need a new Ujoint like Ive seen posted in other threads: Rockford Driveline (part # 430-10A) for about $30.

Yes? Thanks in advance.

most of those are t2 shafts with a NA connector at the transmission so my best guess would be t2 u-joints

Just so I understand: You're saying I probably have a t2 shaft with a NA connector at my T2 tranny? Why wouldn't someone use a t2 u joint there? Is this common?

Not the most common of swaps, but definitely a viable alternative to a full turbo drivetrain swap. Mazdatrix sells a T2 trans to NA diff driveshaft. It's the last one on their list. They also list the replacement u-joint.
http://www.mazdatrix.com/g9.htm

Seems more likely they're using the Mazdatrix shaft instead of finding another driveshaft that happened to fit.

Check to see if your u-joints are replaceable. Hell, first of all, make sure your u-joints are actually bad. Then see if they're replaceable. If they are, take the bad one out and measure it up.

Look at the bottom of the first page here:
http://rockforddriveline.com/Staked-In_U-Joints.pdf

Measure the 2 measurements, then go to a driveshaft shop to see what they can get for you. You might find it's a common size.

So a little development.

I can measure that the ujoint ear is about .002 of an inch out of round from dis-assembly of the factory U joint. The "A" tab from your diagram above. With this discovery it that something a drive shaft shop can handle or am I looking for a new turbo II drive shaft?

Also - the rear is connected to the diff via a machined plate. Since the bolt pattern was larger on the turbo II drive shaft a machinist move the bolt holes in and I've verified that is balanced.

Lastly, I have access to the rest of the blown turbo II car that this tranny came out of. Should I just go take the whole rear assembly and get a new turbo2 shaft and call it a day?

Yes, the TII rear end w/ axles is a stout improvement over the NA cars. If the driveshaft is bolted to the differential using a machined plate, the driveshaft is 99.9% likely to be a TII driveshaft. So if you want, contact a driveshaft shop or search the internet for a place selling the 430-11 u-joint to replace yours. It's actually very easy to replace them, you just need a dremel and some basic hand tools.

I'd replace the u-joints and have the driveshaft balanced. I wouldn't suspect that .002" is enough to really affect the balance.

first time that i did a turbo swap i did used a turbo 2 driveshaft and a na rear end with no problems,the driveshaft is centered on the rear end flange the same way a brake rotor is center on a hub(no way 2 mess it up)then i drill the holes use the stock bolts and 7 years down the road 500hp pull still running strong and it has never vibrated at all.

Excellent, thanks!

I may just grab the read end with a replacement axle and call it a day. The .002 is noticeable but that as close as I can get it from .08 that it was before. And it isn't the U-Joint that is out of spec, but the actual "teeth" that connect to the U-Joint - make sense?

Teeth?

I think it's picture-posting time :)

Sorry, my memory card in my phone quit working. I'll make a diagram, in PAINT!

https://farm9.staticflickr.com/8026/...03239a6d_c.jpg

I'm going out on a limb here, but I really do think that's fine. I can't see any issue with such a small change in the yoke ears. I have changed out hundreds of u-joints before and have had to seriously beat on the yoke to get some out.

Go ahead and grab one of these and replace the u-joint, then swap in the rest of the TII drivetrain. If the machined plate is off, it'll cause a vibration. The easiest way to fix that issue is installing the diff and halfshafts from the TII.

Aren't all TII differentials limited slip too?

Cool, I think that's the direction I'm going to go too.

And yeah, so far as I know all TII's are LSD.

See! There you go, it's a winning situation all around :)

i know this is dead but i thought the turbo2 shafts have the na conector at the hogs head not the trans?

or some asshat dremeled out the holes to mount the TII driveshaft to the n/a differential nose, causing an imbalance.

sorry, i know human nature all too well.