I installed an LT1 aluminum driveshaft in my 91 RS convertible with 700R4. I have had the old driveshaft off before for a speedo gear swap and put it back in with no drips.

Now that I have installed the LT1 DS, I have a small leak.

Is there a minor difference in tolerance between a steel OEM and the aluminum yoke on the LT1. The part came from a chevy dealer and appears to be physically identical to the one I pulled out.

Any advice is appreciated, and thanks in advance,

GCore45

 

Did you put some grease on the driveshaft before you stuck it into the tranny? Even that won't prevent damage to the seal if the seal is very old. Pop a new seal in the tranny and you should be fine.

 

I'll give it a try.
Thanks,
GC

 

You could also check for play between the driveshaft yoke and the tailshaft bushing. Depending on how many miles are on your '91, it could be worn from the OEM steel driveshaft. Are you replacing because of a vibraton? A bad driveshaft will wear out the tailshaft bushing which allows the yoke to move around more wearing out the seal as well causing a leak. Good luck.

 

I didn't think the yolks were aluminum too. There are two types of yolks, one has no hole in the end plug (near the driveshaft). The other type has a small hole in the plug but uses a collar and o-ring on the transmission output shaft right behind the speedo gear. A mismatch in these parts will cause a leak or a plug blowout.