Hello all.
I have a few questions about the rear end, trailing arms, berings, U-joints... etc.
First off, how many miles is recommended before the trailing arms need rebuilt or replaced (including the berings). Is there any "rule of thumb" or obvious indications that the berings or U-joints or other components are starting to go bad? My '76 seems to have a "slapping" noise during coast to acceration while driving straight. It sounds like the U-joints going bad but all the other components are probably orginal and could be the cause too. There is also a slight vibration between 45 and 55MPH which seems to be coming from the rear. I also have a squeaking noise while crusing (and I have no idea what is causing it.) I have changed the rear diff fluid and added the GM posi stuff and that seemed to help some with the vibration, but the other problems still exist.

Second, if I do decide to replace virtually all of the components (ie: rebuilt trailing arms, new U joints, berings, and radius rods) where is a good place to get it aligned? What type of questions should I ask at the auto garage about their experience with the very unique rear drive train of a Corvette?

Any input to this long winded post would be helpful.
Thanks in advance.
Dave K.

There is no real rule of thumb for this. It depends on how the car was driven, what type of conditions it was driven in, maintance, where it was stored, and sometimes just luck.

It sounds like you have a bad u-joint or two. All of you descriptions fit. I would check them first. Check all of them, drive shaft and halfshafts.

well..

I like to think of particularly iffy parts like a corvette rear suspension as a good use of the "if in doubt, throw it out" philospohy..

they do go out and get more expensive to fix the farther they go..

you need to bite the bullet and rebuild the rear suspension/differential before something very bad happens..if the spindle cracks and the wheel falls off at 70 mph youll wish you did..

unless your the first owner.. assume that at some point a 20 yr old got to beat on it.

Hi Dave
You did'nt mention how many miles your car has,but at 28
years old you can assume that everything is real tired.
I replaced every nut and bolt in my 78 rear suspension 3 years ago and could'nt be happer with the results!
I had good luck with Zip products in Virginia for stock
replacement parts and Vette Brakes in Florida for upgrade
parts. It/s not cheap to do it right,but if you spend the
time and money now you will never have to touch the rear
again and you can move on to other areas of the car!
Don't cheap out and have patience- you will be rewarded!
Steve
May The Force be with you!

Thanks for the advice. My Vette does have 118000 miles, and I was thinking of just replacing everything back there (except the diff). Yes, the cost is a little much, but it is peace of mind.

The question remains though, where do I get it aligned after the repairs? Not too many shops know how to properly align the rear end of a vintage Vette.

Well I know it is a good long drive for you but there are several specialty corvette dealers and restorers in chicago. D&M corvette comes to mind here. You can do some internet searches for a corvette specialty shop in your state if your afraid of bubba doing a job on your car. Thats all the cents I can throw in.(probably just two cents) P.S. I am 22 years old, and if your car had a guy like me for the last owner, you need to rebuild the whole Drivetrain and suspension. LOL

The Alignment Shop in Tallmadge Oh. It's a long drive, but I will stick my neck out and say there is no one better than Jerry Grimm. I have seen him and his crew do some amazing things. Including on many Corvettes.

Alignment: Had Car-X in St. Charles do mine. He's got about the best machine in the area and likes muscle cars. Only charged me 100 bucks, drives great, no problems. I don't believe you need a Corvette Specialist to do this.

Bearings: Grasp each rear wheel at 12 and 6, again at 3 and 9. Play at 12 and 6 only indicates worn strut bushings and/or differential yokes. The yokes should have no more then .050" play in and out. Play at 3 and 9 indicates bad wheel bearings.

U-joints: any play felt or observed while twisting in opposite directions indicate failed u-joints.

The other people that have replied are most likely correct though, Over 100,000 miles and all those years your rear suspension is certainly tired and should be completely gone through. I will emphasize my feelings on those differential yokes, excessive end play means certain disaster for the rear end, and really the entire rebuild. The yokes and the strut rods are the only thing that holds the wheels in correct vertical alignment. Here's a guy in Beloit that does excellent rear end work, and is very reasonable: http://corvetteperfection.com/corvetteperfection001.htm

Thanks for all the insight. I'm going to try to get the car through this summer and decide what I'm going to do in the fall. This way I'll have a head start on what I'm getting into as far as cost and labor.

Thanks again!

Dave K.

Hi Dave
When you rebuild your rear suspension don't ignore the diff it is a load bearing part of the IRS! Idealy there
would be a upper A arm in these cars to support the wheel load and just let the half shafts transmit torque to the rear wheels however the job of supporting the top half of the rear wheels is put on the half shafts and transmited through the stub axels to the pinion shaft.
This puts undue load on the stub axles and the spider gear pionion shaft! If you break an axle shaft your rear wheel will colapse!
I imagine that in about 61 when Zora was pushing for IRS ,management probably only agreed to it if he could do it cheap.
I hope someone from VBP is reading this.
Copyright 2004 Steve Hill