Rear Noise - ZR-1 Net Registry Forums

vettn71 · 11-22-2009

When I took my 90 out this morning I noticed that at 50 mph or higher there seems to be a slight vibration and a low "rumble" type sound. Nothing very clear, more like an under tone to the tire noise. It doesn't change when the clutch is pushed in, and under 50 it doesn't seem to be evident. I checked the bearings by jacking the car up and moving the tire with my hands at 3 & 9 and then at 6 & 12, but didn't feel any movement. Tried moving the half shafts and driveshaft, but didn't feel any play there, either. Tires are almost new and haven't had any issues with them. Any ideas?

Jim

Jagdpanzer · 11-22-2009

Had a similar experience after putting on a new set of GY D3s couple of years back. Turned out to be the tire balancing. Had the everything road-force balanced on a Hunter GSP9700 machine http://www.gsp9700.com/
at a local tire shop and that solved it.

rhipsher · 11-22-2009

I've had the same damn thing I start to hear it from 68mph to 80mph. It's definitely speed related. It almost sounds like the tire roar of a big knobby tire on a 4X4. I thought it might be the drive shaft being out of balance. All my ujoints are brand new Splicers so I knew it wasn't them. And I got a four point alignment and that didn't take care of it. So I've just learned to live with it.

USAFPILOT · 11-22-2009

I was always told that a noise like that from the back of the car would be the rear end. I wonder?

rhipsher · 11-23-2009

Quote:

Originally Posted by USAFPILOT

I was always told that a noise like that from the back of the car would be the rear end. I wonder?

Yeah but which part of the rear end would make a noise like that. I've thought of everything. Rear gears maybe? Wheel bearings? Tire balance? drive shaft balance? I gave up along time ago trying to pinpoint that noise and the cause. I just can't afford to throw money at it by replacing everything that it could be. I'm waiting for somebody to chime in and say they had the same problem and found what the cause was. This is the first time I've ever seen a post addressing this. I thought I was the only one. It doesn't seem to affect the drive ability. It's just kind of annoying.

tomtom72 · 11-23-2009

You are sure that the fluid level is okay in the rear & trans? You don't think that this is a bad case of exhaust resonance, or something loose in the exhaust system? Or maybe the spare tire carrier is loose, or the jack is loose? The tires are okay, you didn't loose a weight off of a wheel or have a flat spot or a belt go bad?

I hate to say this but if it's not the rear hub bearings, and you are sure that all the u-joints are good on the 1/2 shafts and the drive shaft joints also.....then it only leaves the stub axles, carrier side bearings and pinion bearings.

Other than that I'm stumped. Usually a low pitch rumble is either the u-joint needles in the first stages of failure, or the rear bearings going south, usually the axle bearings make noise like that.

I wonder if those teflon washers used in the rear hubs could make this symptom if they wear excessively?

rhipsher · 11-23-2009

Quote:

Originally Posted by tomtom72

You are sure that the fluid level is okay in the rear & trans? You don't think that this is a bad case of exhaust resonance, or something loose in the exhaust system? Or maybe the spare tire carrier is loose, or the jack is loose? The tires are okay, you didn't loose a weight off of a wheel or have a flat spot or a belt go bad?

I hate to say this but if it's not the rear hub bearings, and you are sure that all the u-joints are good on the 1/2 shafts and the drive shaft joints also.....then it only leaves the stub axles, carrier side bearings and pinion bearings.

Other than that I'm stumped. Usually a low pitch rumble is either the u-joint needles in the first stages of failure, or the rear bearings going south, usually the axle bearings make noise like that.

I wonder if those teflon washers used in the rear hubs could make this symptom if they wear excessively?

I removed the spare and jack for wieght reduction. All the ujoints are brand new. Trans fluid is full. Not sure about the rear diff fluid. My wheel bearings have a little play in them but I don't think they would make a roaring noise. When I'm at 80mph I can put the car in neutral and as it coast down to around 68mph the roar pitch start to go down and gets quieter kinda like a single engine air plane dive bombing. It's tire rotation speed related not rpm related.

QB93Z · 11-23-2009

I don't know if this applies to your situation, but on the first long trip I took in my 1994 ZR-1 with new tires, when I got on the highway I got an unusual noise that I became convinced was the differential. It went on for a while and I amost abandoned our trip to return home for repairs. Then we exited from one interstate to another with a different road surface and the noise went away immediately. Since then I have noticed the noise on new asphalt surfaces. I guess my tires just don't like the texture of that stuff.

Jim

rhipsher · 11-23-2009

I guess some tire tread could be louder than others. The only other Z I've ever driven was Brads 92 and I drove it for two hours back to Houston and I didn't hear any noise at all. That car was nice and tight other than the sound of the corsa there were no other unusual noises. This sound is exclusive to the rear end and no where else. I think there are probably a good chunk of us that have an issue with our cars that has puzzled us for years that we'd love to to get resolved and this is mine. You can only look prod and poke so long before you just throw up your hands and just give up on it. One day I'll just take it to Corey and say fix it. And he will find it and fix the cause of that noise thats been bothering me all of these years in no time. I just have to get it over to him.

vettn71 · 11-24-2009

It's nice to know this isn't an isloated issue. The thing that bothers me most is that I've owned the car for a year and haven't noticed it before. Maybe my hearing perked up or something. I am running Sumitomos, but again, this seems to be a new noise. I thought about the differential, but there's no leaks or seepage. As far as the u-joints, they seem tight, but I haven't tried to watch and listen with the car up on jack stands. Maybe I can convince one of my sons to get under the car when it's runnign 60mph in fourth!

Jim

11-22-2009	#1
vettn71 Join Date: Oct 2008 Location: Colleyville, TX Posts: 272	Rear Noise When I took my 90 out this morning I noticed that at 50 mph or higher there seems to be a slight vibration and a low "rumble" type sound. Nothing very clear, more like an under tone to the tire noise. It doesn't change when the clutch is pushed in, and under 50 it doesn't seem to be evident. I checked the bearings by jacking the car up and moving the tire with my hands at 3 & 9 and then at 6 & 12, but didn't feel any movement. Tried moving the half shafts and driveshaft, but didn't feel any play there, either. Tires are almost new and haven't had any issues with them. Any ideas? Jim

11-22-2009	#2
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,646	Re: Rear Noise Had a similar experience after putting on a new set of GY D3s couple of years back. Turned out to be the tire balancing. Had the everything road-force balanced on a Hunter GSP9700 machine http://www.gsp9700.com/ at a local tire shop and that solved it.

11-22-2009	#3
rhipsher Join Date: Aug 2008 Location: Houston, TX Posts: 2,314	Re: Rear Noise I've had the same damn thing I start to hear it from 68mph to 80mph. It's definitely speed related. It almost sounds like the tire roar of a big knobby tire on a 4X4. I thought it might be the drive shaft being out of balance. All my ujoints are brand new Splicers so I knew it wasn't them. And I got a four point alignment and that didn't take care of it. So I've just learned to live with it.

11-22-2009	#4
USAFPILOT Join Date: Aug 2007 Location: Spring TX Posts: 1,341	Re: Rear Noise I was always told that a noise like that from the back of the car would be the rear end. I wonder?

11-23-2009	#6
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,609	Re: Rear Noise You are sure that the fluid level is okay in the rear & trans? You don't think that this is a bad case of exhaust resonance, or something loose in the exhaust system? Or maybe the spare tire carrier is loose, or the jack is loose? The tires are okay, you didn't loose a weight off of a wheel or have a flat spot or a belt go bad? I hate to say this but if it's not the rear hub bearings, and you are sure that all the u-joints are good on the 1/2 shafts and the drive shaft joints also.....then it only leaves the stub axles, carrier side bearings and pinion bearings. Other than that I'm stumped. Usually a low pitch rumble is either the u-joint needles in the first stages of failure, or the rear bearings going south, usually the axle bearings make noise like that. I wonder if those teflon washers used in the rear hubs could make this symptom if they wear excessively? __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member Last edited by tomtom72; 11-23-2009 at 10:35 AM. Reason: because I'm slow.

11-23-2009	#8
QB93Z Join Date: May 2007 Location: Westminster, Maryland Posts: 3,684	Re: Rear Noise I don't know if this applies to your situation, but on the first long trip I took in my 1994 ZR-1 with new tires, when I got on the highway I got an unusual noise that I became convinced was the differential. It went on for a while and I amost abandoned our trip to return home for repairs. Then we exited from one interstate to another with a different road surface and the noise went away immediately. Since then I have noticed the noise on new asphalt surfaces. I guess my tires just don't like the texture of that stuff. Jim

11-23-2009	#9
rhipsher Join Date: Aug 2008 Location: Houston, TX Posts: 2,314	Re: Rear Noise I guess some tire tread could be louder than others. The only other Z I've ever driven was Brads 92 and I drove it for two hours back to Houston and I didn't hear any noise at all. That car was nice and tight other than the sound of the corsa there were no other unusual noises. This sound is exclusive to the rear end and no where else. I think there are probably a good chunk of us that have an issue with our cars that has puzzled us for years that we'd love to to get resolved and this is mine. You can only look prod and poke so long before you just throw up your hands and just give up on it. One day I'll just take it to Corey and say fix it. And he will find it and fix the cause of that noise thats been bothering me all of these years in no time. I just have to get it over to him. Last edited by rhipsher; 11-23-2009 at 10:54 PM.

11-24-2009	#10
vettn71 Join Date: Oct 2008 Location: Colleyville, TX Posts: 272	Re: Rear Noise It's nice to know this isn't an isloated issue. The thing that bothers me most is that I've owned the car for a year and haven't noticed it before. Maybe my hearing perked up or something. I am running Sumitomos, but again, this seems to be a new noise. I thought about the differential, but there's no leaks or seepage. As far as the u-joints, they seem tight, but I haven't tried to watch and listen with the car up on jack stands. Maybe I can convince one of my sons to get under the car when it's runnign 60mph in fourth! Jim