Fevre

Put my car up on jack stands to try and figure out what all the rumbling was about:

http://forums.corvetteforum.com/zerothread?id=399174

and I find the back right tire seems to have a catch in it. I started the car and put it in gear and that tire looks like it is going over a small bump every revolution. Rotated it to see how often it caught/bumped and it happens in the same place each time around. Also makes a squeeking sound that seems to be coming from the u-joints. Any ideas to what could be wrong? U-joint, wheel bearing,....? Any ideas as to how to further diagnose?

Thanks

Chris

sb69coupe

If you're trying to rotate the tires with them hanging down, it won't work. The u-joints on the half shafts will bind, which sounds exactly like what you're describing. Raise the wheels to the proper ride height and you should be able to rotate them without hitting this problem.

Shannon

SmokedTires

Chris with the car up in the air, this is common with our cars to see the wheel move up & down while rotating (caused by the u-joints binding when the halfshafts are angled with the car up) .

I haven't read your semptoms(sp?) yet, being that I was disgusted with the fact the sooooo many Corvette owners wouldn't help out a brother in need :nonod: .

SmokedTires

Reading your other post, if you can wiggle the driveshaft by hand, then this would be the first area to examine :yesnod: . You could take the tranny to someone to have it rebuilt if it is a bearing, or go with a new 5speed. IMO, an O/D tranny is right up there for one of the best updates done with our ole cars ;) .

GaryS

As others have stated, you should never run the engine with the wheels off of the ground. The suspension was not designed to work with that angle. VERY BAD stuff can happen.

I would say that with the suspension off of the ground, you need to start testing things out. It would be nice if you knew if this was speed related, transmission related, or engine related. Since you don't, start out by checking out the u-joints, the half shafts and the driveshaft. The other posts have told you how to check out the driveshaft, but you can also check out the half shafts by grasping the tire at the 6 and 12 o'clock position. Try tipping the tire in and out at the top and bottom. You should get minimal movement. Too much movement and then you will need an assistant to watch the half shaft where it enters the differential to see if you have excessive play.

Gary

PRNDL

Glad you guys mentioned this! I have never had occasion to try to run the vette (in gear) while up on stands, but if there was some reason to try it I never woud have thought it could be bad for the car. Now I know, without having to learn the hard way!! :lol: MJ

LiveandLetDrive

I would be interested to know what needs to be done to correct the excessive play in the halfshafts you mentioned. I tried to get a 4corner alignment but they said that there was too much of that top to bottom type play in the wheel to do it. Among other things :)

-Chris

Desertdawg

Did you check your muffler bearings yet????? :jester

Desertdawg

Please ignore the above post. Dry Arizona humor at work.


Move along nothing else to see here......

Fevre

No but I did check the fizzer valve, it's all ball bearing now a days ya know. :jester

Funny thing is that I am only getting it on one side and can detect no signs of binding. I have ran it once before on stands to work on a speedo problem and did not experience any of these symptoms. Was planning to replace all my u-joints and rebuild the front and rears suspension but would like to figure out what the problem is so I don't miss fixing it.

GaryS

Chris, in my limited experience with half shaft end play, I have noticed that the end of the half shafts will wear and be eroded away. There is a gent nearby who rebuilds differentials for Corvettes for a living and I have watched him take several apart. The end of the half shaft that goes into the differential is held in with a large C clip. Often this clip falls off and allows the half shaft to move in and out. Other times I have seen it where the entire end of the half shaft is eaten or worn away. :eek: The bottom 1/4" was missing and there wasn't anything for the C clip to grab onto, so it was at the bottom of the case. My 66 had excessive play and when we pulled it apart, there was minor erosion but nothing excessive. A rebuild of the differential was in order since it was out and open. After the rebuild, the system was tight and up to specs. A new clutch pack took care of the excessive play. Btw, for those that drive their Corvettes a lot, there is a new half shaft that has hardened ends. It will not be worn away by use. Something to consider.
Gary

TedH

Replace "half shaft" with "Side yoke" in above post and I think we have the core problem in your differential; combined with worn u-joints. You may also want to have your rear bearing assemblies rebuilt while you are at it (if they haven't been rebuilt yet). Van Steel in Clearwater, FL specialize in the rear diff, half-shafts and bearing assemblies.

Fevre

Thanks Gary

I was planning on tearing the diff down just to see what cond it is in. I know it is leaking some but I check the diff fluid last night and it was still pretty much full. Looks like I have a big winter project ahead of me with putting in a 5 speed, rebuild the diff and susp so everyone shuld expect lots of ?'s.

Scooter70

Chris,
If you're going to have your rear end rebuilt this winter, maybe we could get a volume discount. I'm searching for someone in the area to do mine right now. After the Cruise to Hell, I think it'll be just about time for me to start the winter projects.

Fevre

I got so much I want/need to do I don't know where to start. :crazy: I am probably going to do the diff myself but that is open to change. My valve stems are leaking like crazy, I get a cloud of smoke on start . Read you are having a similar problem. I think I am just going to yank my engine and trans this weekend and start measuring up what I got to do to get the 5-speed in. Maybe we can swap out some labor. :)