75W-140 gear oil
Thread Starter
Drifting
Joined: Dec 2012
Posts: 1,717
Likes: 28
From: O'Fallon IL
75W-140 gear oil
Folks,
I'm experiencing the famous rear end chatter on my 08. I researched some and found that there's a tsb (below) on that. It basically calls for replacing the fluid with the latest GM 75W-90 fluid. Now, I have 3 quarts sitting in my garage of Royal Purple 75W-140 that I was planning to use on my previous build. Do you guys think that this will be too much(thick) to run? I don't want to ruin the rear end. Thanks in advance.
Date: 01-09-2008
TSB: #07-04-20-002A
Document ID# 2048181
2005 - 2008 Chevrolet Corvette
Subject: Rear Axle Clunk and/or Chatter Type Noise on Turns
(Drain/Refill Rear Differential Fluid) #07-04-20-002A - (01/09/2008)
I'm experiencing the famous rear end chatter on my 08. I researched some and found that there's a tsb (below) on that. It basically calls for replacing the fluid with the latest GM 75W-90 fluid. Now, I have 3 quarts sitting in my garage of Royal Purple 75W-140 that I was planning to use on my previous build. Do you guys think that this will be too much(thick) to run? I don't want to ruin the rear end. Thanks in advance.
Date: 01-09-2008
TSB: #07-04-20-002A
Document ID# 2048181
2005 - 2008 Chevrolet Corvette
Subject: Rear Axle Clunk and/or Chatter Type Noise on Turns
(Drain/Refill Rear Differential Fluid) #07-04-20-002A - (01/09/2008)
SUBVETTE
Joined: Jul 2006
Posts: 3,841
Likes: 93
From: San Diego CA
I don't think you will ruin your differential by using your existing Royal Purple, but if it was me I'd use the recommended GM Dextron LS Gear Oil 75W-90 (which contains the limited slip friction modifier) because I know that it works to cure the chatter. Took care of my chatter as soon as I put it in. (Part #88862624)
Thread Starter
Drifting
Joined: Dec 2012
Posts: 1,717
Likes: 28
From: O'Fallon IL
I don't think you will ruin your differential by using your existing Royal Purple, but if it was me I'd use the recommended GM Dextron LS Gear Oil 75W-90 (which contains the limited slip friction modifier) because I know that it works to cure the chatter. Took care of my chatter as soon as I put it in. (Part #88862624)
Le Mans Master
Joined: Jan 2005
Posts: 5,611
Likes: 5
From: Thousand Oaks California
Folks,
I'm experiencing the famous rear end chatter on my 08. I researched some and found that there's a tsb (below) on that. It basically calls for replacing the fluid with the latest GM 75W-90 fluid. Now, I have 3 quarts sitting in my garage of Royal Purple 75W-140 that I was planning to use on my previous build. Do you guys think that this will be too much(thick) to run? I don't want to ruin the rear end. Thanks in advance.
Date: 01-09-2008
TSB: #07-04-20-002A
Document ID# 2048181
2005 - 2008 Chevrolet Corvette
Subject: Rear Axle Clunk and/or Chatter Type Noise on Turns
(Drain/Refill Rear Differential Fluid) #07-04-20-002A - (01/09/2008)
I'm experiencing the famous rear end chatter on my 08. I researched some and found that there's a tsb (below) on that. It basically calls for replacing the fluid with the latest GM 75W-90 fluid. Now, I have 3 quarts sitting in my garage of Royal Purple 75W-140 that I was planning to use on my previous build. Do you guys think that this will be too much(thick) to run? I don't want to ruin the rear end. Thanks in advance.
Date: 01-09-2008
TSB: #07-04-20-002A
Document ID# 2048181
2005 - 2008 Chevrolet Corvette
Subject: Rear Axle Clunk and/or Chatter Type Noise on Turns
(Drain/Refill Rear Differential Fluid) #07-04-20-002A - (01/09/2008)
I would not use 75W-140 in the Corvette. 75W-140 is more suited for something like the Silverado.
I also had the "stick-slip" condition in my differential. The GM Dexron LS (75w-90) fixed this condition.
Melting Slicks
Joined: Dec 2006
Posts: 2,694
Likes: 106
You need to buy 3 man. My GS, with fluid cooler, took almost all 3. And remember to start the car in the air (car must be level) and run it in 2nd gear at 15 mph for a minute. Then shut engine off, and top off differential again. If your car doesn't have a cooler, it should still take over 2 quarts, if you drained it properly (car level). Good luck.
Thread Starter
Drifting
Joined: Dec 2012
Posts: 1,717
Likes: 28
From: O'Fallon IL
You need to buy 3 man. My GS, with fluid cooler, took almost all 3. And remember to start the car in the air (car must be level) and run it in 2nd gear at 15 mph for a minute. Then shut engine off, and top off differential again. If your car doesn't have a cooler, it should still take over 2 quarts, if you drained it properly (car level). Good luck.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
5 Best & 5 Worst Corvette Daily Drivers
Joe Kucinski
The Headlights of Every Corvette Generation Explained
Joe Kucinski
5 Best & 5 Most Overrated Corvette Track Packages of All Time!
Joe Kucinski
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
Thread Starter
Drifting
Joined: Dec 2012
Posts: 1,717
Likes: 28
From: O'Fallon IL
Drifting
Joined: Apr 2006
Posts: 1,276
Likes: 5
From: Ambler Pa.
Folks,
I'm experiencing the famous rear end chatter on my 08. I researched some and found that there's a tsb (below) on that. It basically calls for replacing the fluid with the latest GM 75W-90 fluid. Now, I have 3 quarts sitting in my garage of Royal Purple 75W-140 that I was planning to use on my previous build. Do you guys think that this will be too much(thick) to run? I don't want to ruin the rear end. Thanks in advance.
Date: 01-09-2008
TSB: #07-04-20-002A
Document ID# 2048181
2005 - 2008 Chevrolet Corvette
Subject: Rear Axle Clunk and/or Chatter Type Noise on Turns
(Drain/Refill Rear Differential Fluid) #07-04-20-002A - (01/09/2008)
I'm experiencing the famous rear end chatter on my 08. I researched some and found that there's a tsb (below) on that. It basically calls for replacing the fluid with the latest GM 75W-90 fluid. Now, I have 3 quarts sitting in my garage of Royal Purple 75W-140 that I was planning to use on my previous build. Do you guys think that this will be too much(thick) to run? I don't want to ruin the rear end. Thanks in advance.
Date: 01-09-2008
TSB: #07-04-20-002A
Document ID# 2048181
2005 - 2008 Chevrolet Corvette
Subject: Rear Axle Clunk and/or Chatter Type Noise on Turns
(Drain/Refill Rear Differential Fluid) #07-04-20-002A - (01/09/2008)
SUBVETTE
Joined: Jul 2006
Posts: 3,841
Likes: 93
From: San Diego CA
Team Owner
Joined: Sep 2000
Posts: 25,029
Likes: 2,719
From: Far NW 'burbs of Chicago
St. Jude Donor '13
On our 2009, I had the diff and A6 fluids changed around 7k. At 50k, I had them changed again and sent samples to Blackstone Labs. They said that both the fluids and the tranny & dif were in excellent condition, suggested I go a little longer next time.
Melting Slicks
Joined: Dec 2006
Posts: 2,694
Likes: 106
Forgot to comment my diff fluid was absolutely filthy at less than 2K miles. I thought it was black/dark. But when I poured the new fluid, it was basically clear (yellowy clear). Probably contaminated with all kinds of assembly crap, plus break-in metal dust. Not a bad idea to change it at least once initially IMO.
Race Director
Joined: Oct 2005
Posts: 14,999
Likes: 200
From: Bay Area Ca.
As a interesting side note my DTE built differential calls for 75-140 Redline fluid every year minimally.
They do make some changes concerning oil delivery and clutch pack material changes as well as other upgrades with half shafts and some cryo treatment with the ring and pinion gears. I'm not sure how much effect these build changes have regarding the need for heavy oil.
Maybe they just want to keep the gears quite and the heavy oil helps...
They do make some changes concerning oil delivery and clutch pack material changes as well as other upgrades with half shafts and some cryo treatment with the ring and pinion gears. I'm not sure how much effect these build changes have regarding the need for heavy oil.
Maybe they just want to keep the gears quite and the heavy oil helps...
Thread Starter
Drifting
Joined: Dec 2012
Posts: 1,717
Likes: 28
From: O'Fallon IL
As a interesting side note my DTE built differential calls for 75-140 Redline fluid every year minimally.
They do make some changes concerning oil delivery and clutch pack material changes as well as other upgrades with half shafts and some cryo treatment with the ring and pinion gears. I'm not sure how much effect these build changes have regarding the need for heavy oil.
Maybe they just want to keep the gears quite and the heavy oil helps...
They do make some changes concerning oil delivery and clutch pack material changes as well as other upgrades with half shafts and some cryo treatment with the ring and pinion gears. I'm not sure how much effect these build changes have regarding the need for heavy oil.
Maybe they just want to keep the gears quite and the heavy oil helps...
Race Director
Joined: Sep 2000
Posts: 11,146
Likes: 1,913
From: Missouri City, TX
It will take somewhat less than 2 qts on a drain and refill basis for the standard non-cooled differential. I know that for a fact as I have already done my 07 vert several years ago. 2.11 qts would be the amount for a disassembly/overhaul job, i.e., completely dry sump.
Thread Starter
Drifting
Joined: Dec 2012
Posts: 1,717
Likes: 28
From: O'Fallon IL
Good to know since I was already questioning myselfbif 2 quarts would be enough. Thanks.
Melting Slicks
Joined: Dec 2006
Posts: 2,694
Likes: 106
My car is a '12 GS dry-sump (might be different from a base/vert; I don't know), and I can tell you it took more than 2 before messing with the cooler. Just buy 3, and keep the rest for next fluid change. Otherwise don't let it drain overnight, because you'd be short. And I didn't do anything special: drained the differential with car perfectly level. If you raise the front, you can actually drain a bit more. After doing the cooler, it was almost 3 qts. And I poured the fluid with a clear tube over the rear right wheel, so almost zero waste (just a few drops when it was full). If you have a pump, and a diff. cooler, 3 would be barely enough since it can't suck a bottle completely dry. Good luck.
SUBVETTE
Joined: Jul 2006
Posts: 3,841
Likes: 93
From: San Diego CA
You definitely need to buy 3 bottles if you use a transfer pump, as I did. The pump will retain some after you are done plus if you are like me you are bound to spill a little. I ended up with anout 2/3 of a bottle left over.