85W140 / Gear whine trouble shooting
#1
Member
Thread Starter
Join Date: Jan 2002
Posts: 188
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1990 Firebird Formula
Engine: LT1
Transmission: T56
Axle/Gears: 3.42
85W140 / Gear whine troubleshooting
I recently installed an `02 rear end in my car. I was told it had 12k on it.
When I filled up the diff I used the Coastal 85w140 and posi additive from Autozone. Is this stuff bad news to use in a 10 bolt?
I am getting a bit of gear whine (compared to the old rear end), and I am wondering if this can be part of the cause.
Of course I am having other issue with the car that may also be culprut, the main one being that the new rear end installed seems to be offset about an inch the passengar side.
I'm thinking the old rearend was also offset and I didn't notice. Being that the 4th gen rearend is 3" wider, its a bit more pronounced.
I also installed a new LS1 driveshaft and new u-joints at the same time, but highly doubt any relation there.
The only other thing I can think of that may also be making the noise more noticable is that I went with Spohn LCAs with the poly bushings.
Any thoughts?
When I filled up the diff I used the Coastal 85w140 and posi additive from Autozone. Is this stuff bad news to use in a 10 bolt?
I am getting a bit of gear whine (compared to the old rear end), and I am wondering if this can be part of the cause.
Of course I am having other issue with the car that may also be culprut, the main one being that the new rear end installed seems to be offset about an inch the passengar side.
I'm thinking the old rearend was also offset and I didn't notice. Being that the 4th gen rearend is 3" wider, its a bit more pronounced.
I also installed a new LS1 driveshaft and new u-joints at the same time, but highly doubt any relation there.
The only other thing I can think of that may also be making the noise more noticable is that I went with Spohn LCAs with the poly bushings.
Any thoughts?
Last edited by RaGe; 04-05-2004 at 02:32 PM.
#5
Member
Thread Starter
Join Date: Jan 2002
Posts: 188
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1990 Firebird Formula
Engine: LT1
Transmission: T56
Axle/Gears: 3.42
Since your car with sagging springs sits just like your friends car with lowering springs, do either of you have any kind of rear end noise possibly from the driveshaft being at an odd angle?
I am down to 1 of 4 things here... 1- The diff fluid I used is too thick and making the rear end noisy, 2- the Rear end is so misaligned that the driveshaft pinion angle is making the noise, 3- My tires suck *** and I just don't remember them making noise before, 4- This rear end I bought is junk.
Lets hope its something simple!
The noise seems most pronounced between 30-50mph... and if I play with the throttle I can hear a little more noise like almost a rattling from the rear end.
Maybe I am just nuts and the polly bushings made everything a little louder!
I am down to 1 of 4 things here... 1- The diff fluid I used is too thick and making the rear end noisy, 2- the Rear end is so misaligned that the driveshaft pinion angle is making the noise, 3- My tires suck *** and I just don't remember them making noise before, 4- This rear end I bought is junk.
Lets hope its something simple!
The noise seems most pronounced between 30-50mph... and if I play with the throttle I can hear a little more noise like almost a rattling from the rear end.
Maybe I am just nuts and the polly bushings made everything a little louder!
#7
Supreme Member
iTrader: (2)
Join Date: Feb 2002
Location: Nashville TN
Posts: 1,141
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1989 Trans Am
Engine: 355 HSR
Transmission: Pro-Built 700r4 w/ 3400 converter
Axle/Gears: 10 bolt w/ 3.42 gears
You are not getting whine b/c the diff fluid is too thick. If anythign that would help b/c it would be a thicker layer of protection between the metal to metal contact, which is where the whine would come from.
It could be that the pinion angle is messed up, but I really dont' think that would cause that big of an issue. What kind of life did that rear end have? If it was beat on at the track w/ slicks, then they is probably considerable wear on those teeth, and they will howl some. Question is this... Is it a bad whine, or just something that is annoying you? Gears whine. Its part of the game. If its something that is extremely loud, or accompanies w/ a vibration, then you may have a problem. Could it be that you are being overly cautious b/c you you did the install and don't want any problems???
It could be that the pinion angle is messed up, but I really dont' think that would cause that big of an issue. What kind of life did that rear end have? If it was beat on at the track w/ slicks, then they is probably considerable wear on those teeth, and they will howl some. Question is this... Is it a bad whine, or just something that is annoying you? Gears whine. Its part of the game. If its something that is extremely loud, or accompanies w/ a vibration, then you may have a problem. Could it be that you are being overly cautious b/c you you did the install and don't want any problems???
Trending Topics
#8
Member
Thread Starter
Join Date: Jan 2002
Posts: 188
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1990 Firebird Formula
Engine: LT1
Transmission: T56
Axle/Gears: 3.42
You are not getting whine b/c the diff fluid is too thick. If anythign that would help b/c it would be a thicker layer of protection between the metal to metal contact, which is where the whine would come from. It could be that the pinion angle is messed up, but I really dont' think that would cause that big of an issue. What kind of life did that rear end have? If it was beat on at the track w/ slicks, then they is probably considerable wear on those teeth, and they will howl some. Question is this... Is it a bad whine, or just something that is annoying you? Gears whine. Its part of the game. If its something that is extremely loud, or accompanies w/ a vibration, then you may have a problem. Could it be that you are being overly cautious b/c you you did the install and don't want any problems???
The wine isn't bad, just annoys me. I have heard much louder rear ends than this one, and yes I am definatly being overly cautious.
Maybe I just need a louder exhaust!
Thread
Thread Starter
Forum
Replies
Last Post
UltRoadWarrior9
Transmissions and Drivetrain
3
09-02-2015 08:24 PM