Drain and replace differential fluid?
Thread Starter
Melting Slicks
Joined: Jun 2007
Posts: 2,655
Likes: 3
From: Castro Valley California
Drain and replace differential fluid?
Why would I "need" to replace my '05/C6 'Vette's differential fluid? It has just over 30.9K miles on the odometer. It is also an A4, fyi.
Thanks, in advance, to all inputs.
Thanks, in advance, to all inputs.
Melting Slicks
Joined: May 2004
Posts: 3,017
Likes: 2
There have been a couple of revisions to GM's diff fluid since 05..There is a TSB on rear differential clunk that the new fluid takes care of . I had my 08 changed a couple of weeks ago and it really quieted low speed noises that I was hearing.
Thread Starter
Melting Slicks
Joined: Jun 2007
Posts: 2,655
Likes: 3
From: Castro Valley California
This "rear differential clunk" you refer to, is this something that is a mechanical issue or just a "normal" sound the differential makes when shifting/meshing/etc.? I've noticed the "clunk" (some even might call it a "groan"?) on occasion, more often heard at very low speeds (under 30mph).
Safety Car
Joined: Jan 2006
Posts: 4,598
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From: Miami FL
2020 C6 of the Year Finalist - Unmodified
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16,'17,'18-'19-'20-'21-'22
You are indeed hearing the "Stick-Slip Friction" in the limited slip clutch components in your differential. If you have a 10mm allen socket and a set of socket wrenches it is pretty easy to change the differential fluid, and you will see an immediate benefit.
Not to mention getting rid of 30k miles of wear debris in the old fluid.
Not to mention getting rid of 30k miles of wear debris in the old fluid.
Pro
Joined: Nov 2006
Posts: 667
Likes: 0
From: Eagle River Alaska
Here is a link as to how to do a DIY fluid change out. 
I changed mine out at 10k. I used
- Amsoil Severe Gear Synthetic Extreme Pressure (EP) 75W90 Lubricant
(2qts)
- Amsoil Slip-Lock Differential Additive (8 oz)
Hope this helps
I changed mine out at 10k. I used
- Amsoil Severe Gear Synthetic Extreme Pressure (EP) 75W90 Lubricant
(2qts)
- Amsoil Slip-Lock Differential Additive (8 oz)
Hope this helps
Thread Starter
Melting Slicks
Joined: Jun 2007
Posts: 2,655
Likes: 3
From: Castro Valley California
Just as an fyi to all the CF-brothers (and sisters), I found this "new" GM-differential fluid with the additive already added to it (GM part# 88862624) for $22.24 per quart (need 2). This is "supposedly" specifically engineered for the Corvette. Though, many of the parts-guys I spoke to said they also "spec" this for their trucks too.
Be advised, there are some dealers out there that will sell you the "old" fluid (GM part# 89021677) AND the 4-oz. additive (GM part# 1052358) for almost double the above part #. I experienced some dealers had the new "all-inclusive" fluid, some did not. Pricing on the 2-products usually was around $35 per quart of the diff-fluid and 4-oz. additive (at around $11 per container - only need one container per application).
Be advised, there are some dealers out there that will sell you the "old" fluid (GM part# 89021677) AND the 4-oz. additive (GM part# 1052358) for almost double the above part #. I experienced some dealers had the new "all-inclusive" fluid, some did not. Pricing on the 2-products usually was around $35 per quart of the diff-fluid and 4-oz. additive (at around $11 per container - only need one container per application).
