Attempting to diagnose this for a friend before it is purchased. When I accelerate, I hear a squeeking sound from under the car, possibly back by the rear end or the drive shaft. If I coast, no squeek. It seems to do it in all gears (although I cannot really hear it when I am going faster because the ground noise and car noise). The squeek is quiet pronounced and gets more steady as I go faster until I cannot hear it. I looked underneath but cannot tell much there.

Check all the rubber bushings and differential front mount for deterioration. My quess would be that the front diff. mount is shot and allows the diff. to rotate up into the retaining strap!

This has happened to me twice before. Mainly happens on sealed for life universal joints, (no grease nipple) but can happen to any uni joint.

Is the squeak present only driving forward or in reverse as well?

If it is only in one direction check all the uni joints but the drive shaft uni's are the usuall suspect.

Hope this helps.

Alan.

Never heard it going backwards, although I do get an interesting noise when braking and using the clutch as well. The car has a good 'thump' when you engage the clutch unless you baby the clutch (read between the lines - no drag racing. Damn.).

Perhaps a trip to Tulsa driveline is in order? Will a professional be able to tell anything?

Or should I reserve a Saturday afternoon, five friends, a keg of beer, and alot swearing?

Can anyone recommend a good u-joint for my Z?

Definately sounds like the uni joint, but as 240ZX says check the diff mount as well.

Before you drive too much further get underneath and check the drive shaft.

On the first occasion it happened to me it was the front joint that let go completely and because the driveshaft was still connected by the rear uni the front fell to the road, bounced straight back up again and thru the floor. Not a pretty sight, either were my pants when I $^!# myself.

Alan.

You creat a lovely picture there. Thanks. I needed a laugh.

Just out of curiousity, anyone know how much something like this will cost to replace?

U joint is the first choice.Then I would check all rear and front rubber bushings.Remember the right rear is the torque wheel.That power shifts things more than we realize.I assume you are not thin enough to look under the car without jacking it up.That changes everything when you do.Myself,If a visual inspection failed I would spray wd/silcone whatever on all misc. moving areas a little at a time until I had a change. .Go Fish!!

If the sqeek is related to speed , in that it increases as you gain speed , It's a u-joint . When they get to this point they must be replaced , lubeing them wont hilp. As to cost I have no idea as to labor charge but you can get cheep joints for about $15. each or $23. for the best ones. If you spring for the better ones you will never need to do them again. They are not hard to change and you have 6 all total two on the drive shaft and the rest on the rear axels ( half shafts) . dipper:classic: