Which differential gear oil to use?
Thread Starter
Melting Slicks
Joined: Oct 2001
Posts: 2,803
Likes: 0
From: Panama City Beach FL
Which differential gear oil to use?
I found Mobil1 SAE 75W-90 and Pennzoil Synthetic 75W-90 gear oil. Mobil1 sells for $9/qt, Pennzoil at $4/qt. Is there any differences between the two? Any experiences with using either one?
Melting Slicks
Joined: Aug 2001
Posts: 3,050
Likes: 124
From: Wichita KS
Re: Which differential gear oil to use? (luvinc5)
Corvette shop manual calls for: Rear Axle Limited Slip Differential SAE 75W-90 Synthetic Axle Lubricant, GM P/N 12378261 or equivalent meeting GM specification 9986115. With complete drain and refill add 114ml (4oz) of limited slip differential lubricant additive GM P/N 1052358 or equivalent.
Do your alternative oils meet the GM spec? The differential capacity is 1.7 quarts of lubricant plus 4 oz of limited slip additive. Not much price difference overall.
Do your alternative oils meet the GM spec? The differential capacity is 1.7 quarts of lubricant plus 4 oz of limited slip additive. Not much price difference overall.
Safety Car
Joined: Sep 2001
Posts: 4,411
Likes: 1
From: Wilmington NC
Re: Which differential gear oil to use? (luvinc5)
I found Mobil1 SAE 75W-90 and Pennzoil Synthetic 75W-90 gear oil. Mobil1 sells for $9/qt, Pennzoil at $4/qt. Is there any differences between the two? Any experiences with using either one?
http://www.myoilshop.com/SynGrOil.html
Le Mans Master
Joined: Oct 1999
Posts: 8,205
Likes: 40
From: Tucson AZ
Re: Which differential gear oil to use? (luvinc5)
Gm engineers spent a lot of time on this; theirs is the best for the Corvette. That being said, I have Amsoil in mine and will put it in the new car too. Goos stuff. If you use Mobil 1, which is fine, be sure to put in the LS additive too. :yesnod: :)
[Modified by carpe dm, 3:56 PM 6/2/2003]
[Modified by carpe dm, 3:56 PM 6/2/2003]
Thread Starter
Melting Slicks
Joined: Oct 2001
Posts: 2,803
Likes: 0
From: Panama City Beach FL
Re: Which differential gear oil to use? (mapman)
Corvette shop manual calls for: Rear Axle Limited Slip Differential SAE 75W-90 Synthetic Axle Lubricant, GM P/N 12378261 or equivalent meeting GM specification 9986115. With complete drain and refill add 114ml (4oz) of limited slip differential lubricant additive GM P/N 1052358 or equivalent.
Do your alternative oils meet the GM spec? The differential capacity is 1.7 quarts of lubricant plus 4 oz of limited slip additive. Not much price difference overall.
Do your alternative oils meet the GM spec? The differential capacity is 1.7 quarts of lubricant plus 4 oz of limited slip additive. Not much price difference overall.
Melting Slicks
Joined: Aug 2001
Posts: 3,050
Likes: 124
From: Wichita KS
Re: Which differential gear oil to use? (luvinc5)
.... I can't find any explicit statement on either bottles stating they meet GM specs. But are the GM specs exceeding the std specs for synthetic 75w90 gear oil?
If you are stuck in the Twilight Zone somewhere, I would use the correct weight lubricant from a name brand company and revert to known GM specification lubricants as soon as possible. However, most of us are not far from the local Chevy dealer, so getting the correct lubricant is not a problem.
Just not enough money to be saved using alternative oils, given the potential cost of repairs. Compared to the cost of the car, the correct lubricants are pretty cheap. Why do it?
Thread Starter
Melting Slicks
Joined: Oct 2001
Posts: 2,803
Likes: 0
From: Panama City Beach FL
Re: Which differential gear oil to use? (mapman)
If you are stuck in the Twilight Zone somewhere, I would use the correct weight lubricant from a name brand company and revert to known GM specification lubricants as soon as possible. However, most of us are not far from the local Chevy dealer, so getting the correct lubricant is not a problem.
Just not enough money to be saved using alternative oils, given the potential cost of repairs. Compared to the cost of the car, the correct lubricants are pretty cheap. Why do it?
Just not enough money to be saved using alternative oils, given the potential cost of repairs. Compared to the cost of the car, the correct lubricants are pretty cheap. Why do it?
Burning Brakes
Joined: Jul 2002
Posts: 938
Likes: 2
From: IL
Re: Which differential gear oil to use? (Richin Chicago)
I'll second Redline 75w90.
Gear oil change on the C5's is the easiest thing in the world. Perfect drain plug location and fill plug location isn't bad at all. Easy and can be done quickly. Kudos to GM on this one. It's only a shame that they screwed up the refill on the automatic transmissions! ;) Now there is a pain in the ol rear...
[Modified by H82BFST, 5:52 AM 6/3/2003]
Gear oil change on the C5's is the easiest thing in the world. Perfect drain plug location and fill plug location isn't bad at all. Easy and can be done quickly. Kudos to GM on this one. It's only a shame that they screwed up the refill on the automatic transmissions! ;) Now there is a pain in the ol rear...
[Modified by H82BFST, 5:52 AM 6/3/2003]
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Intermediate
Joined: Mar 2003
Posts: 48
Likes: 0
From: Denver colo
Re: Which differential gear oil to use? (H82BFST)
For hard running, Red Line Heavy Shock Proof oil has been doing an amazing job in Phil,s C5 Speed GT car. For the street where you run the car cold might not be as good? This lube has done amazing things in other roadracing diff.s for us also due to it's clinging and crush factors. Example: 1967 454 ci. 600 + H.P. and torque Corvette road race car with sticky Hosiers and great rear susspension tuning for BITE! (It didn't hold up without this lube.)
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Re: Which differential gear oil to use? (blktie8)
Using Amsoil here as well. I think if you check some of the oil related forums, you can do much better then the GM fluid. Mobil-1 has caused some issues with some people. Amsoil Series 2000 already has in the additive and so does Redline.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Re: Which differential gear oil to use? (luvinc5)
If you are looking for it to meet the specific part #, it is not stated, if you are looking for it to meet the GL-5 requirements and such, yes.
[Modified by vettenuts, 12:36 PM 6/3/2003]
[Modified by vettenuts, 12:36 PM 6/3/2003]
Le Mans Master
Joined: Nov 1999
Posts: 7,695
Likes: 51
From: Imperial Beach CA
Re: Which differential gear oil to use? (Bandit1)
Always amazes me that one would think that 6 years of success with a car went for nothing and someone out there decides that it's no good and knows better. It seems that with my luck I'm the one who gets stuck with that used car someday. :confused: :mad
Safety Car
Joined: Sep 2001
Posts: 4,411
Likes: 1
From: Wilmington NC
Re: Which differential gear oil to use? (jimman)
Always amazes me that one would think that 6 years of success with a car went for nothing and someone out there decides that it's no good and knows better. It seems that with my luck I'm the one who gets stuck with that used car someday. :confused: :mad
Thread Starter
Melting Slicks
Joined: Oct 2001
Posts: 2,803
Likes: 0
From: Panama City Beach FL
Re: Which differential gear oil to use? (Richin Chicago)
I would agree with Richin Chicago. Not all GM service recommendations/requirements are good....Dexcool comes to mind.
[Modified by luvinc5, 8:33 PM 6/3/2003]
[Modified by luvinc5, 8:33 PM 6/3/2003]
Melting Slicks
Joined: Mar 2001
Posts: 2,372
Likes: 51
From: New Milford CT
Re: Which differential gear oil to use? (luvinc5)
Hotrodding is the uniquely American black art and hobby of making factory automobiles better for our purposes and enjoyment.
Putting better than stock gear oil in the differential falls right in line with that. I use Redline.
Putting better than stock gear oil in the differential falls right in line with that. I use Redline.
Safety Car
Joined: Sep 2001
Posts: 4,411
Likes: 1
From: Wilmington NC
Re: Which differential gear oil to use? (luvinc5)
I would agree with Richin Chicago. Not all GM service recommendations/requirements are good....Dexcool comes to mind.
[Modified by luvinc5, 8:33 PM 6/3/2003]
[Modified by luvinc5, 8:33 PM 6/3/2003]
