[Z06] Changing Z06 diff oil
Thread Starter
Le Mans Master
Joined: May 2005
Posts: 6,366
Likes: 249
From: Fort Lauderdale, Florida
Changing Z06 diff oil
I couldn't find any info. I'm wondering what others have used to replace the differential oil and additives if necessary. I'm thinking of changing it tomorrow once I decide.
Race Director
Joined: Apr 2004
Posts: 16,135
Likes: 5
From: Newberry FL
Cruise-In VIII Veteran
St. Jude Donor '07
Team Owner
Joined: Dec 2008
Posts: 35,874
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From: Honolulu HI
Should be lots of threads on this as well as trans fluid. Royal Purple or Amsoil 75-90, and still add the GM limited slip additive even though they both say you don't need to. Just a little added insurance.
Tech Contributor
Joined: Jan 2004
Posts: 20,030
Likes: 289
From: Wylie TX --> Less is More, except under the hood !
I wrote a procedure on my web site.
http://mysite.verizon.net/res0aae8/webpage.html
Scroll to the bottom for the link to various C5 stuff I wrote.
Toque
http://mysite.verizon.net/res0aae8/webpage.html
Scroll to the bottom for the link to various C5 stuff I wrote.
Toque
Last edited by Toque; Jul 11, 2011 at 07:43 PM.
Racer
Joined: Apr 2011
Posts: 349
Likes: 0
From: central NJ
oh and i also bought amsoil.
Tech Contributor
Joined: Jan 2004
Posts: 20,030
Likes: 289
From: Wylie TX --> Less is More, except under the hood !
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
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From: King George VA
Toque's writeup is very helpful.
For a direct link to the fluid AMSOIL recommends and I use in mine:
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
AMSOIL Slip-Lock Differential Additive (Product Code ADATB)
AMSOIL Hand Pump (Product Code G2039)
Note that the Severe Gear 75w90 comes with friction modifier already in it and for most C5/C5 Z06 diffs adding extra additive is not normally needed to prevent diff chatter. I don't use extra additive in mine. Some, such as Toque, chose to add extra additive. Won't hurt the diff to add extra additive and this may turn out to be a decision of convenience. My normal advice is not to add the extra additive with the fill. If the diff does chatter, then add a few ounces of the additive. The Slip Lock comes in a tube with a long nozzle and it would be easy to open the diff fill plug and squirt in a few ounces of the Slip Lock to a full diff without having to drain and replace your fluid.
For a direct link to the fluid AMSOIL recommends and I use in mine:
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
AMSOIL Slip-Lock Differential Additive (Product Code ADATB)
AMSOIL Hand Pump (Product Code G2039)
Note that the Severe Gear 75w90 comes with friction modifier already in it and for most C5/C5 Z06 diffs adding extra additive is not normally needed to prevent diff chatter. I don't use extra additive in mine. Some, such as Toque, chose to add extra additive. Won't hurt the diff to add extra additive and this may turn out to be a decision of convenience. My normal advice is not to add the extra additive with the fill. If the diff does chatter, then add a few ounces of the additive. The Slip Lock comes in a tube with a long nozzle and it would be easy to open the diff fill plug and squirt in a few ounces of the Slip Lock to a full diff without having to drain and replace your fluid.
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Racer
Joined: Apr 2011
Posts: 349
Likes: 0
From: central NJ
i just changed mine today. pretty straight forward, leveling the car was the biggest problem for me did it as best as i could. again, many thanks to toque for his great walk-through!
holy crap does that old rear diff fluid smell terrible... uaaaargh.
holy crap does that old rear diff fluid smell terrible... uaaaargh.
Thread Starter
Le Mans Master
Joined: May 2005
Posts: 6,366
Likes: 249
From: Fort Lauderdale, Florida
I was all set to use the GM fluid. At the last minute I spoke to an engineer at Royal Purple and asked some info on their fluid. I wound up using the RP Maxgear 75-90. It needs no additional additive. I know everyone will think I must be on drugs but the diff seems quieter and smoother running, even though I didn't notice any noise before. It still seems quieter like no gear hum at all. I don't know exactly how long since the last fill but mine was a little stinky coming out too.
Le Mans Master
Joined: Jul 2009
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From: Los Angeles California
Instructor
Joined: May 2009
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From: Europe
Can you post a picture? The diff drain plug on my car does not have a built in washer/gasket (like the engine plug has). It's just a flat surface, hence my question about the washer. I know the diff oil was changed before I changed it and I'm pretty sure the plug is the OEM one.
Edit: Plug is idential to the one in Toque's guide. The washer on my car was a separate one.
Edit: Plug is idential to the one in Toque's guide. The washer on my car was a separate one.
Last edited by C5_Z06; Jul 22, 2011 at 04:05 PM.
Thread Starter
Le Mans Master
Joined: May 2005
Posts: 6,366
Likes: 249
From: Fort Lauderdale, Florida
Can you post a picture? The diff drain plug on my car does not have a built in washer/gasket (like the engine plug has). It's just a flat surface, hence my question about the washer. I know the diff oil was changed before I changed it and I'm pretty sure the plug is the OEM one.
Edit: Plug is idential to the one in Toque's guide. The washer on my car was a separate one.
Edit: Plug is idential to the one in Toque's guide. The washer on my car was a separate one.
