Synthetic Differential Oil

[butler]

Hi Bob,

I have been reading some of your posts. I'm not a great Carlisle fan myself. Too crowded and usually too hot. Also, everything is so overpriced.

Does Mobil 1 make a synthetic oil for the differential? I had a problem with mine making noise, so the dealer changed the fluid and put an additive in it. It stopped for a while, and I put about 1,000 miles on it and it seems like its coming back. Someone said to switch over to a better synthetic differential oil, and the additive that GM uses actually slows you down. I don't know if you know anything about rear ends or the type of grades that should be used or what after market brands other than GM's could be used. Or should I just change it again?

[Robert Pache]

Yes, Mobil makes a synthetic gear oil. It is Mobil 1 Synthetic Gear Lubricant and is a 75W-90 grade. I have seen it available at Pep Boys and it should be available at other auo stores. Mobil also makes Mobil 1 Synthetic ATF for anyone interested.

Bob

[DavisZR1]

Originally posted by Robert Pache
Yes, Mobil makes a synthetic gear oil. It is Mobil 1 Synthetic Gear Lubricant and is a 75W-90 grade. I have seen it available at Pep Boys and it should be available at other auo stores. Mobil also makes Mobil 1 Synthetic ATF for anyone interested.

Bob

Bob, how do you rate it in comparison to the GM synthetic?

[Robert Pache]

I cant really say because I have not looked at the GM oil and am not sure who the supplier is. However, I am confident that Mobil 1 gear oil is at least equal in performance and meets API GL-5 specifications. It is also Indy 500 certified and provides outstanding performance in the trans and differentials of our NASCAR teams , Car 2, Rusty Wallace and Car 12, Ryan Newman. It is also used in our IRL team cars. This oil should not be used in the C5 six speed, which requires an ATF.

Bob

[team-zr1]

Originally posted by Robert Pache
I This oil should not be used in the C5 six speed, which requires an ATF.

Bob

Why should the Mobil I syn ATF not be used in the MN6 6 speed trannie ?

I have been using it in my MN6 for about 1 year even doing high speed racing and have had no ill issues.
I swapped to Mobil ATF for it foams less then stock fluid which did heat up quicker and then dump put vent tube.

I have done my own trannie/transaxle cooler and no problems with either using Mobil I products in both.

[Robert Pache]

I am sorry that you may have misunderstood me. I do endorse the use of Mobil 1 Synthetic ATF in the C-5 Six speed. It is the Mobil 1 Synthetic 75W-90 gear oil that can not be used.

Bob

[butler]

Bob,

What does the factory use in the C5 six speed as gear oil? Synthetic or regular? If it does use regular does it hurt to change to synthetic, or visa versa? Thank you.

BTW...Welcome aboard TeamZR1. I love when you open the hood and see that LT5 engine. Very impressive. One of the greats!

[DavisZR1]

Yes welcome Team-zr1. We have a category for us ZR1er's here. Did you check it out? ZR1 Mark is another new member. :chevy:

[team-zr1]

Originally posted by butler
Bob,

What does the factory use in the C5 six speed as gear oil? Synthetic or regular? If it does use regular does it hurt to change to synthetic, or visa versa? Thank you.

BTW...Welcome aboard TeamZR1. I love when you open the hood and see that LT5 engine. Very impressive. One of the greats!

Thanks, The ZR-1 was the best Corvette I have owned since my first vette in 1974 and is a super open road race car.
The LT-5 is clearly the best engine I have seen in a common buy off the showroom floor car.

As I mentioned I am using in the C5 MN6 the Mobil 1 synthetic and being the whole *** end transmits heat onto each other, including the exchaust pipes and that the cases do not transfer heat very well, the stock fluid in high speed events like ORRs will heat up quickly, fluid foams and expands and then pukes out the vent tube at the top.

At one ORR maintaining speeds in excess of 150 MPH, the fluid for over 60 miles was venting out, onto exhaust pipes and I had a white plume of smoke the whole time.
Best case though it to install a good cooler which I have done to both trannie and transaxle.

The Mobil 1 does not foam as quickly and where the shifting is not good for the MN6 with the Mobil 1 the shifting got better.

[team-zr1]

Originally posted by DavisZR1
Yes welcome Team-zr1. We have a category for us ZR1er's here. Did you check it out? ZR1 Mark is another new member. :chevy:

Thanks, I got my first ZR-1 in 1994 and raced it until 2000.
At speeds in the 180s the extra weight the car has is a blessing and with a better oil cooler it sings well in the 7,000 RPM range.

If you think it is fast, I owned the Mobil 1 GM/Morrison ZR-1 snakeskinner which is 1,000 lbs less then a stock ZR-1 and with a Hewland trannie hauls *** like you would not believe.

I now racing a C5 and I can say the LT-5 is still the king of performance but deserved a better trannie the the ZF.

[Robert Pache]

Corvette uses a non synthetic Dexron III fluid. Mobil 1 synthetic ATF meets the Dexron III performance requirements and will ,of course, provide superior heat and were protection.

Bob

[butler]

Originally posted by Robert Pache
Corvette uses a non synthetic Dexron III fluid. Mobil 1 synthetic ATF meets the Dexron III performance requirements and will ,of course, provide superior heat and were protection.

Bob

Thanks Bob. I am going to change over to the synthetic in the tranny. I really appreciate your response to my question.:nod: