Hello all

I'm in need of some help with my 1976 280z. I went for a fairly long drive today (~25miles or so) to the local u-pull it junkyard and the store to pick up groceries. When I got in my car all was find but when I put it in gear and started backing up I get a fairly loud squeeking noise that sounds like it is coming from the rear. It grows louder and faster with the speed of the car. As the car nears 50 the rear begins to "roar" is the best way to put it.

My u-joints are not in very good shape at all so could it be them? Half-shafts?

Advise is welcome

Thanks

Jan

Sounds like bad bearing in the diff from lack of oil? Maybe?

Dave

lack of oil? Really I poured in gear oil until it started pouring out of the pour hole. Maybe I need to add more?

**EDITED*** for my Jumping the gun, These words really need facial expressions to know when attitude is or isn't apparent.

I apologize,

Dave

Edited November 15, 200915 yr by Zs-ondabrain

Whoa Dave. There was no ill wishes in those remarks. I didn't mean for it to sound smartassish* if it did. I'm sorry. I'm just a bit confused on how low fluid could cause a squeeking sound.

I'll look into the low fluid later this weekend.

Jan

Well in that case, I apologize.

By your description of it turning into a "Roar" at higher speeds, sounds exactly like my 510 did when I ran it low on gear oil. In which case, I burnt a bearing and it was absolutely Horrable at higher speeds.

My best suggestion would be to jack it up from the diff, and physically turn the wheels, one side at a time and listen for the sound. Could be brake shoes, U-Joints, bearings in the diff or stub axles on the strut assemblies, etc, etc.

If you can't turn if fast enough to get the sound pinpointed. maybe have a driver start the car and slowly let out the clutch while it's in the air, you can get a better idea of where it's coming from while outside the car. The driver can immediately hit the brakes if an issue arrives (jack slipage etc.

Dave

Dave I took your advise, kind of and took the car for a short drive and did some investigating. This is what I found. The squeek noise I'm talking about is coming from the rear of the car (behind my head when I'm driving) and occurs at slow speeds. Once I reach about 10 to 15 mph the sound "goes away" but there is a sound of sorts still there. (What I mean is the loud squeek goes away and is replaced by another sound due to high revolutions).

The noise does not occur (NOT) in reverse. I drove nearly 100 yards in reverse at all speeds and not a single sound. When I press the clutch pedal the sound goes away. So I'm leaning on saying that it is load related. (as with load its there but without its not).

Here are things to keep in mind. My u-joints are toast (according to my mechanic) and the transmission mount is in pretty bad shape last time I looked at it.

Thanks

Jan

Could easily be a dry u-joint on the drive shaft or in the axles. Could also be a bad bearing. Any way of safely putting the car in the air (jack stands, etc) and then listen or have someone listen for location? No issues with the brake or park brake? (hung up shoe or metal contact can make noise, especially forward and not backwards). Even with a diff full of oil, a bad pinion bearing can roar as well.

Let us know. I am curious.

Leonard

Hey guys

Took my car to the mechanic today. Found out that both (yes both) of my rear drums brake cylinders are leaking and have contaminated the brakes themselves. Would that explain the sqeaking noise? I would think it would but I've never had a car with drums before so please advise.

Jan

Ok here is a bit of an update. This past weekend I was changing the oil in my Z. While doing that I lifted the rear of the Z up and rotated both wheels very slowly. The right rear drum brake is rubbing quite a bit. The right one not as much.

Would sticking breaks make a solid squeaking noise? Could it be one of the half-shaft u joints dying?

Thanks

Jan

Based on your latest diagnosis, it appears that the leaking cylinders are the culprits. Pull the drums and inspect for odd-looking wear. Also closely inspect the shoes, springs, etc. to insure everything is still where it should be. A FSM is of great importance, so get one if you don't have one.

I don't think half-shaft u-joints would squeak, but rather would make more of a rumbling or grinding sound.

Frank

Thanks guys for the help. Could a brake related noise be load related? The noise never occurs when I release the gas pedal or press in the clutch. It really annoys me right now.

Thanks

Jan