Rotational Noise coming from Rear end...

[ryan97cobra]

I have my rear seats, insulation, and trunk lining stripped out for installation of a shock tower brace. On my drive to work this morning i noticed a loud rotational noise coming from the rear of the car that i have never heard before. It gets louder the faster i go, and if i put the windows down at 45 i could still hear it over the wind noise, but not by much. I had never heard this noise with rear seats and trunk lining installed back there. I have MM's LCAs with the spherical bushing at the axle mount and Steeda Aluminum Uppers. Is this noise something that is normal, and the only reason i can hear it is because my car is like a tin can right now? Is it something i should investigate?

I replaced my axle bearings and seals last summer and put in Royal Purple axle oil.

 

[Cookieman00x]

Im guessing its going to be your rear whining..

 

[98 svt]

Yup, sounds like gear whine.

How many miles since the gear swap?
Any fluid leak back there?

 

[ryan97cobra]

Yup, sounds like gear whine.

How many miles since the gear swap?
Any fluid leak back there?

I have no idea how long the 4.30s have been in there, i got the car with 120k and it has 141k now and id say they've been in since at least 100k. There is no fluid leak, the driver's side axle seal was leaking last summer that's why i replaced the seals and bearings.

It's not a whining noise like im used to hearing, my transmission whines some when accelerating not much but this just sounds like two metal things rotating against each other and as speed increases the rate at which they rub increases thus the increase in noise.

Ive never had a car with rear end gear whine, my lightning didnt make noise and my 86gt didn't make noise that i could hear but i never had the rear seats out or the trunk lining. I may just not know what that type of whine sounds like.

Either way is this something that needs to be dealt with soon?

 

[98 svt]

Well, it all depends on what's causing the noise.
If it's "just gear whine" than you are ok.
But if it's bad bearings or something, then yes, it needs to be fixed.

 

[Cookieman00x]

Depends on how bad it is. You could always take it to a local dyno shop and see if they can listen to the sound while its on the rollers to help you narrow down where it is comming from.

Did you add friction modifier when you replaced the fluid?

 

[ryan97cobra]

Depends on how bad it is. You could always take it to a local dyno shop and see if they can listen to the sound while its on the rollers to help you narrow down where it is comming from.

Did you add friction modifier when you replaced the fluid?

I used royal purple and was under the impression that i didnt need to add any.

Ill probably take the cover off the housing and inspect the carrier, and look for any metal shavings scratches etc, because when i had it off last summer everything looked very good.

Are you supposed to pack the bearings at the ends of the axle's or just cover them in gear oil?