Drive shaft '91 L-98
 

Anyone pulled the drive shaft on an L-98? I want to replace the U-joints. I know I need to drop the back half of the exhaust. Manual says to remove the driveline support also. Is it really necessary?

I think you will have to remove that driveline support otherwise you wouldn't be able to move the diff back enough to get the shaft out. I chose not to change my drive shaft u joints during my overhaul, because, these stay in a straight line and don't flex very much at all so the wear would be very minimal. I did however change my half shaft u joints and put in brute force forged steel joints.

The driveline support (C-beam) will have to be moved over but not completley removed. This means removing all of the bolts (could possibly leave 1 on the tranny end) and pushing it to one side to get the shaft out.

You do not have to move the diff - the shaft will safely slide into the tranny far enough to get everything apart. Putting the C-beam back is a real PITA but it will eventually go into place with enough messing around.

:iagree:

Thanks
 

Thanks guys. I already replaced the half shaft joints. One of them was in really bad shape. That cleared up a vibration I'd had for a while. Don't feel anything in the propeller shaft U-joints but I already bought them so I'm going to replace them anyway. Didn't think you needed to move the diff. the slip joint on the tranny should handle that ok. Does on most vehicles anyway. I was just hoping I'd be able to do it without disconnecting the support. I've heard other guys describe it the same way (PITA) you did.

Any comments on the sealer the manual recommends applying to the mating surfaces? If you used one what did you use?

I didn't use any sealer last time I took mine apart but most people seem to favor some type of RTV sealant.

No!!! You don't have to remove or even touch the drive line support! Remove the rear u-joint bolts, slide the drive shaft slightly forward, and then you can move the back of the drive shaft to the driver's side. Then just slide it out the back.

It's easy, no need to make a big job out of it by removing the driveline support also.

:iagree:

Thanks Mr6spd! I was hoping someone would say that. I didn't take the straps off and try it but it looks like the thing should do exactly what you suggest. I'll give it a shot this week end. Mine is a 6 speed also.

sealer on the bolts?
 

sealer on the bolts? what does it do? why is it needed?

Not exactly sure what it's for but the Chevy manual says put it on.

Manual states to apply a bead of sealer around the top and bottom mating surfaces on both the transmission and axle and also to the cavity around the bolts. My guess its purpose is a vibration insulation and to prevent noises such as the clunk sound when the system flexes. With that said, I have not used it because it’s such a tight fit getting that thing back in there that I figured most of the sealant would be pushed out anyway. I have had that clunking noise and had to re-torque the bolts. :crazy:

Here here :cheers: :iagree: