So I'm closing in on my slim jim to 700r4 conversion and getting time to order the driveshaft. I have what I think is the stock driveshaft that has the smaller tube w/larger tube driveshaft with the smaller tube insulated with rubber while slid inside the larger tube.

The new trans setup is very close in length. I think it would only need to be shortened about an inch.

I don't know a whole lot about this type of driveshaft. Was this a way to absorb vibrations? For the first 7 days I felt some vibration, had the tires balanced, and that helped a lot. But still felt a little in the rear. Thought maybe the driveshaft was out of balance, then the trans went out, thus the swap.

Would it be wise to ditch this stock driveshaft? It's not really a money issue, just don't want to cause problems from something I don't have info about (i.e. these rubber insulated driveshafts).

Also, I wanted opinions from here, not from the shop whom of course would want to sell me a whole new shaft.
thanks in advance.
Update!!!! Further in this post I bought a used aluminum factory S-10 driveshaft to have shortened. IT IS NOT T6 ALUMINUM and could not be welded by the local driveshaft shop. If you want to try this alternative, you'd probably have to hunt for a stock shaft thats the exact length....and good luck on that...

 

Why trust a 40 plus yr old part. I had a heavy duty 3" made with a new yolk and it cost less than $300 shipped from PST. JKaz

 

I agree with JKaz. You can have a new driveshaft manufactured reasonably. No need to get super high quality if you aren't going to race the car. Just have a shop manufacture you a decent quality replacement that will fit the new transmission.

 

Look at it this way.....would you want to drive on 40 year old rubber tires? I sure wouldn't.

 

I found a driveshaft maker on ebay with 100% positive reviews that will make an aluminum driveshaft for $325. A new one locally with everything here was $289 though that may have been with new name brand u joints, yoke etc etc. So out the door maybe a little over $400 for the aluminum...why not....

It's too bad the two piece carbon fiber driveshaft I got from acura didn't fit. But it has some odd ends that wouldn't have worked. I'm not sure carbon fiber would be good for a street vehicle anyhow.

 

I wouldn't want a carbon fiber drive shaft. I am sure it would cost and arm and a leg and most street driven cars aren't counting pounds that precisley.

 

Carbon fiber is easily damaged by an impact from a rock, banging it while installing, etc. It is intended for racing, period. Aluminum will fatigue over time, although aluminum driveshafts have been used by OEM's. Overall, steel is the best choice for most of us, and the longer it is, the bigger the desired diameter. At "critical speed" meaning rpm, any shaft will whip like a jump rope. Check out www.markwilliams.com tech section for more info. Another good source for driveshafts custom made for your car is www.quickperformance.com

 

I wasn't serious about the carbon fiber thing really.

What I ended up doing:
Bought a used aluminum S-10 driveshaft that already had a 4L60E yoke, u joint felt good. Shop will shorten it. Driveshaft=$135(tax included)+$85 shorten + u joint ($25?)...not bad, Aluminum driveshaft for $245 out the door. New Steel was $289.

Anyhow, I'm still in the process of finishing up the conversion. This time next week i should be cruis'n.

 

Be sure to use the u joint with externally coated cups so they won't have galvanic corrosion with the aluminum yoke.

 

I was unable to have the stock shaft shortened. It was not the standard T6 aluminum so they ended up selling me a fresh made one that was only about $40 more than steel. I noted in my first posting of this thread I was unable to shorten a factory driveshaft.