New tire sound(s)

[Pomorza]

Yes, I am talking about the half shafts. Didn't even think about the actual drive shaft, although that could also cause some thumping. Since you have new U-joints there, that should be just fine.

I thought of a test that you could do to see if you have enough slop in the rear end to cause excessive movement. With the car in gear and the parking brake set, you and a buddy get behind the Z and start pushing it in a rocking motion. While the car is rocking, you should not see any front to back movement on the rear wheels relative to the fender openings. Then try the same trick with the parking brake off. With the car in gear, you should still have a lot of resistance to the rocking motion. If you hear clunking, it is likely your half shaft U-joints.

Apparently the rims were not the problem. I did do the test you asked with the parking brake on and off. With it on the car did not move period. When you take it off it would move but there was no sounds at all that I could tell.

Any other ideas mates? I took it to my other mechanic to get an alignment and asked him to take a look at the suspension to see if he can figure it out.

[Zed Head]

Apparently the rims were not the problem. I did do the test you asked with the parking brake on and off. With it on the car did not move period. When you take it off it would move but there was no sounds at all that I could tell.

Any other ideas mates? I took it to my other mechanic to get an alignment and asked him to take a look at the suspension to see if he can figure it out.

It might help you if you try to separate the drivetrain issues, from the suspension, brakes and wheels, as far as you can. Even if it's just down to fine details of the noise. You said decelerate originally and then later you said decelerate and brake. It's not clear if you're using engine braking, brakes or a combination of both.

If you decelerate just using the transmission and engine braking, is the noise different than using just the brakes with the clutch in or transmission in neutral?

With just brakes you're only loading the wheels and suspension. With engine braking only, you're loading the half-shafts and driveshaft, along with the wheels and suspension.

You might even try stopping hard using just the parking brake, to put more load on the rear wheels.

It might give a few more clues.

[Pomorza]

It might help you if you try to separate the drivetrain issues, from the suspension, brakes and wheels, as far as you can. Even if it's just down to fine details of the noise. You said decelerate originally and then later you said decelerate and brake. It's not clear if you're using engine braking, brakes or a combination of both.

If you decelerate just using the transmission and engine braking, is the noise different than using just the brakes with the clutch in or transmission in neutral?

With just brakes you're only loading the wheels and suspension. With engine braking only, you're loading the half-shafts and driveshaft, along with the wheels and suspension.

You might even try stopping hard using just the parking brake, to put more load on the rear wheels.

It might give a few more clues.

The noise does not differ from the method of driving I have. I put it in neutral, or keep in gear or hit the brakes the noise remains constant. When I drive and do not put load on the rear end (that is I'm no accelerating) the noise is there very loud. When I put a load on it it diminishes in volume but it's still there but harder to hear.

Jan

[Pomorza]

A bit of an update and I hope you all can help here:

I took the Z to my other mechanic to get the alignment done. In the process he found that there is movement in the rear right wheel (the one that makes the noise) and advised me that the bearing is bad. (loose). He reconfirmed that the rear struts are worn to bits and they need replacement.

Secondly we found that the rear end wheels have a 5/8" toe in on both sides. As these are non adjustable does anyone know what could cause them to do this? I took two pictures so you all can see what I'm dealing with.

On a side note, the front tires also had toe in of 5degrees (roughly) on both sides. That was fixed but the rears are still a bit odd.

Any help would be great

Jan

[Zed Head]

A bit of an update and I hope you all can help here:

I took the Z to my other mechanic to get the alignment done. In the process he found that there is movement in the rear right wheel (the one that makes the noise) and advised me that the bearing is bad. (loose). He reconfirmed that the rear struts are worn to bits and they need replacement.

Secondly we found that the rear end wheels have a 5/8" toe in on both sides. As these are non adjustable does anyone know what could cause them to do this? I took two pictures so you all can see what I'm dealing with.

On a side note, the front tires also had toe in of 5degrees (roughly) on both sides. That was fixed but the rears are still a bit odd.

Any help would be great

Jan

Getting closer! I was going to say bearing. Seriously. Anyway...

Your transverse link bushings determine the alignment of the rear wheels (assuming that their mounting points to the body are not misaligned). Are they worn? There are two inner, where the wide part of the link attaches to the frame, and two outer, where it attaches to the strut/bearing housing (the cast iron piece) via the spindle pin. If the inner ones are worn, I've heard (read) that you can get quite a bit of movement of the whole assembly. I think that it would give toe-out under braking, toe-in under acceleration.

There is an account out there from someone about being able to move the whole wheel assembly by hand because the bushings were shot.

There is also talk of poorly drilled bearing housings, from the factory.

I still have my stock bushings though, and my rear alignment seems pretty good, so can't offer much more.

[Pomorza]

Well if the transverse link are the rather large A looking parts of the rear suspension(that hold the wheels to the frame) then I don't think the word "worn" gives justice to what I have left. On all eight I have maybe an inch or two of "bushings" left. These "bushings" are broken, cracked and torn all over. Could having bad rear bushing really cause 5/8ths of an inch of toe in?

To be more specific, pretty much all the rear bushings on my car are shot. The mustache bar bushings are gone so when I shift I get the dreaded "thud". The drivers side strut is leaking oil.

Hope that sheds light on my Z. Its not exactly "perfect" but what can I expect for a care that wasn't really taken care of properly.

Jan

[Zed Head]

Well if the transverse link are the rather large A looking parts of the rear suspension(that hold the wheels to the frame) then I don't think the word "worn" gives justice to what I have left. On all eight I have maybe an inch or two of "bushings" left. These "bushings" are broken, cracked and torn all over. Could having bad rear bushing really cause 5/8ths of an inch of toe in?

To be more specific, pretty much all the rear bushings on my car are shot. The mustache bar bushings are gone so when I shift I get the dreaded "thud". The drivers side strut is leaking oil.

Hope that sheds light on my Z. Its not exactly "perfect" but what can I expect for a care that wasn't really taken care of properly.

Jan

Yes, the transverse link is the A shaped piece. Also called a control arm by many.

If I remember correctly,the guy who had the worn bushings found them because he had a noise from the rear end. If yours are as bad as you describe, they could also be a part of your "thud thud" sound. If your mechanic is not familiar with the these suspensions he might even be mistaking bushing movement for wheel bearing wear.

Each rear wheel assembly is held on to the car by three contact points with the body. The top of the strut and the two inner bushings. They take up all of the turning, braking and accelerating loads.

You really need good bushings to have a good solid car.

[Pomorza]

Yes, the transverse link is the A shaped piece. Also called a control arm by many.

If I remember correctly,the guy who had the worn bushings found them because he had a noise from the rear end. If yours are as bad as you describe, they could also be a part of your "thud thud" sound. If your mechanic is not familiar with the these suspensions he might even be mistaking bushing movement for wheel bearing wear.

Each rear wheel assembly is held on to the car by three contact points with the body. The top of the strut and the two inner bushings. They take up all of the turning, braking and accelerating loads.

You really need good bushings to have a good solid car.

If the noise I'm getting isn't from the bearing, wouldn't I get it on both sides and not just one if the bushings are all worn out? The exact phrase I was told was that rear right tire has movement (that is when it is in the air he can move it around by pulling and pushing on it).

Jan

[Zed Head]

If the noise I'm getting isn't from the bearing, wouldn't I get it on both sides and not just one if the bushings are all worn out? The exact phrase I was told was that rear right tire has movement (that is when it is in the air he can move it around by pulling and pushing on it).

Jan

No offense intended, but I would find someone who knows these cars and let them crawl under it and look around. I know a little about cars and most mechanical things and I spent quite a while under my car after I got it thinking "What the heck is that and how does it work?" and "Is that all that holds the rear wheels on?" and "It's just a big chunk of rubber!" as I searched for my own "clunk" (it was the diff mount and a bad half-shaft u-joint and loose moustache bar bushings).

You can't really tell by looking alone, that the bushings are bad. You have to torque parts around while someone looks (or vice versa). My diff mount looked like it had new rubber, but it was half split and worthless.

Yours should be fairly easy since you have visible wheel movement. Just watch the link mounts while someone moves the wheel. Watch the joint at the spindle pin also. As far as one side to the other, they might not have worn evenly.

[Pomorza]

No offense intended, but I would find someone who knows these cars and let them crawl under it and look around. I know a little about cars and most mechanical things and I spent quite a while under my car after I got it thinking "What the heck is that and how does it work?" and "Is that all that holds the rear wheels on?" and "It's just a big chunk of rubber!" as I searched for my own "clunk" (it was the diff mount and a bad half-shaft u-joint and loose moustache bar bushings).

You can't really tell by looking alone, that the bushings are bad. You have to torque parts around while someone looks (or vice versa). My diff mount looked like it had new rubber, but it was half split and worthless.

Yours should be fairly easy since you have visible wheel movement. Just watch the link mounts while someone moves the wheel. Watch the joint at the spindle pin also. As far as one side to the other, they might not have worn evenly.

I'm going to take it up to some Z expert(s) to ask their opinion. I've heard from a number of sources that bad bushing can cause that type of issue though.

Thanks

Jan

[Samuel]

Hi,

Nice to see the thread which is good from my and others point also and can be important also

car ECU