Has anyone changed the u joints on the axle drive shafts of an '82 or similar Vette? The reason I am considering swapping the joints is a thumping noise in the passenger side rear at ~ 20 mph. I put the car up on jacks and ran the car in gear. No noise...? New exhaust and nothing rubbing there, so I'm thinking u joints.
My Chilton's manual says to loosen the camber adjusting nut and rotate the cam so the high point faces inward, to push the control rod outward. I know I can mark it before I move it, but was concerned I might affect the wheel alignment if I tinker with the camber adjusting nut. Seems like there would be room to drop the shafts without moving the control arm. Any input from someone who has done it before would be appreciated.

 

When I did my 81 I had to loosen & remove the control arms to get the axle shafts out. I would have an alignement done on the rear once you have completed the job. Remember to mark right & left and which side goes toward the diff. Not a bad job

 

I took the shafts off of my '81 to paint them & managed it without disturbing anything else. I had the car up on axle stands at the rear so that both rear wheels were off the ground, loosened off the UJ straps (12 point 1/4" socket?), & then was able to turn the wheel to a position where the shaft could be removed. It was fiddly (especially getting it all back together), but at least I didn't have the hassle of getting an alignment done (or the worry of some animal adjusting it by bending the rod with a large hammer!). Maybe I was just lucky, but before following the manual and removing everything it's worth trying as it can save a lot of work/time. I also had a jack under the wheel so that I could raise it slightly if needed when getting the shaft in/out but can't remember if I had to use it or not.

 

the U-joints can be replace quite easily. I had a similar situation. I put the car in gear and heard a thump but the U-joints seemed fine. I changed them all and still a thump. It turned out to be a missing rubber bumper at the front of the diferential...or in that area. What was happening is the differential was jumping a bit and hitting the metal above. I replaced the bumper and thump went away.

Jim

 

I plan to replace my u-joints soon but the cap bolts require a 12 point "star" socket. Where did you guys pick one up?

 

I know Sears has them in their Craftsman stuff, but you have to buy a whole set. Those are Torx sockets. Auto Zone has them individually, and I see them also at Harbor Fake (Freight) for a few bucks. I ended up getting an impact set, and because of the thicker wall had to turn it down on a lathe a bit. Now it's custom fit for those hard to reach places on the halfshafts.

I didn't have to adjust my camber out any to remove the halfshafts. Some do and some don't have to. Hopefully you won't have to, but it's not a big deal. I lift the car using a 4 inch wide channel iron going across under the back of the car, cut to length to reach the shock mounts on each side (I use a jack in the center to get it up, then block it on either side under the channel). I do it on my lift with a jack tray, but have done it on the ground, also. Maybe lifting at that point helps relax things enough so I don't have to do any camber release. In any case, it's not super critical if you mark the cams first and put them back in the same spot when you are done. Sometimes they can be really frozen. No alignment should be necessary if they were correct in the first place. I have VBP adjustable strut rods, which I highly recommend over the stock setup. They are easy adjustments to change back and forth for street or autocross.

 

No offense, but it kind of bugs me when someone asks a question like this. Just about anything that can be done to these cars has been done by one or more forum members...especially when it comes to wear parts like u-joints. That said, welcome to the madhouse...before long, we'll have you doing a frame-off restoration with all sorts of crazy performance mods.

 

Actually, it probably doesn't hurt to ask any question. That's what the forum is for - abeit, yes it gets repetitive now and then. Sometimes the answers get buried away and its just easier to ask. Gives some of us who didn't see the old ones a chance to express our opinions (good or bad). And - Right you are - it won't be long and he'll be well into it with other great projects. Seems everyone has to do the u-joints at least once and first, then the fun begins.

Love the Blue, Ken.

 

Thanks for the info. I changed one broken u-joint using a 9 mm box end but one of my bolts on another u-joint was about to round off and I did not want to push it.

Your advice regarding marking the strut rods is right on. Adjustable strut rods are on the (very long) "to do" list.

 

I'll give it a try without moving the camber adjusting nut and see what happens. Thanks for the input guys.

 

Does anyone have a website link or a source of info (book) on replacing the U-Joints in a C3? Maybe a step by step with pictures?

 

If you buy the chassis service manual for your year of car, not the Chilton's, but the GM Service manual, it will tell you how to do this job.

 

any place that sells sockets. Its a pretty common socket. I have a home depot husky set hat has the 12 point sockets

 

Thanks for the info guys, I found what I was looking for on Google

http://www.corvettemagazine.com/2007...ft_u-joint.asp

http://www.corvettemagazine.com/2005...nt/u-joint.asp

 

Not what I said - I find the implication that a common job hasn't been done by anyone in the past to be rather odd. Just my humble opinion.

U-joints aren't hard - an old thread of mine has some excellent advice from Norval.

 

I got mine from NAPA.. You can by just the sockets you need....