My manual for my 02 GMC states to only use r/e diff lube meeting GM Specification #9986115. My question is does Schaeffer's #267 lube meet this GM spec?
Bob?
Butch 02 Sierra Denali
Bob?
Butch 02 Sierra Denali
GM r/e lube specifications
- Thread starter Butch 02 Sierra Denali
- Start date
- Status
I don't think anybody here knows... This very question was asked below.
I for one--probably others-- looked it up at the Schaeffer's website. There was no mention of that particular spec... so... ??
I for one--probably others-- looked it up at the Schaeffer's website. There was no mention of that particular spec... so... ??
that same spec # is in my 2002 Camaro owners manual and was in my 1999 Camaro manual. I've tried to find out what it actually is and have had no luck. My guess is all the spec says is a gear oil meeting GL-5 specification, and maybe containing EP additives to protect the gears. What else could it be? I don't think there's much more than that to the differential gears and I'd bet just about every gear oil today that's GL-5 rated and between 75w-140 weight meets that spec.
Butch,
I can't answer your question about the Schafer's but I believe your Denali comes from the factory with Synthetic 75w90 GL5 Axel Lube and 9986115 is GM's spec for this lube.
I just bought some Mobil 1 75w90 Synthetic (6.99/Quart) for my 2003 2500HD Silverado and I understand the GM lube is about $25/quart at the dealer.
The following is some relevant info that was posted on another Forum I read
(my apologies if this is not allowed here).
"Here is some info Eaton sent me in the past:
GM introduced the new body style in 1998. At the same time they upgraded
the differential and changed to a synthetic lube. The G80 is specifically designed to give ultimate performance with this lube, and the lube contains special additives that help reduce slip stick that occurs between the clutches. the GM synthetic lube typically runs about 100+ degrees cooler than mineral base lube, which is better if you do allot of towing or heavy hauling. I would recommend that you stay with the GM synthetic, not Mobil 1. If you don't tow or haul you could use the pre 1998 mineral lube without
degrading performance of the differential. this would be a cheaper option but require more lube changes. " "Axle tolerances of the 1/2 ton trucks are very tight. The recommended procedure was to change lube after 500 miles of heavy towing, which would is considered a break in period. This breaking period generates high heat conditions in the axle which was found to degrade the synthetic beyond the point of mineral lube. After the 500 mile lube change, the axle is broke in and does not generate the high heat. If you use GM synthetic after the break-in period, it can be considered "lube for life", although some say to change it at 40,000 - 50,000 mile intervals." "If you don't tow, don't worry about the oil change as it a waste of money." "If your truck is pre 1998 or the old style, it comes with mineral lube. IN that case you need to stay with mineral because the seals are designed to work with it. If you changed from mineral to synthetic you'll cause your seals to swell and eventually leak. It's ok to go from synthetic to mineral because you won't cause swelling. many of your stop leak chemicals effect seals in this manner, resulting in a short term fix but a long term problem."
Back in November, I received the following:
"From Mr. Ralph Holmquist of Eaton, the maker of the locking differential:
"The maintenance schedule for the rear axle was developed by American Axle & Manufacturing and GM truck based on multiple tests. The Eaton locker does not require additional maintenance nor does it add heat to the lube. The lube will darken due to the carbon wear on the clutch surfaces, much the same as a disc brake pad & rotor. This does not damage axle components such as seals or bearings. However, a new axle can produce excessive temperatures (plus 350 degrees F) due to the ring & pinion breaking in that will break the lube additives down. Avoid high loads, trailer towing and high speed extended driving during the initial break in of the vehicle. After the break in period axle temps will level at a much lower figure. Lube changes are a good idea because the additives are replenished and contaminates such as casting sand are eliminated. The axle is filled at the factory with a synthetic 75w90 GL5 rating made by Texaco under part # 2276. The GM service # is 12378261. This is the only lube we have done extensive testing with to insure locker compatibility. The only negative to using one of these other lubes is an increased potential for clutch chatter. This really doesn't hurt anything and can be corrected by changing the lube. I noticed in the latest GM owners manual the term "or equivalent" when referring to the lube specification. Look for a GL5 rating on the bottle to make sure the ring & pinion, seals & bearings are protected. Limited slip additive is not needed." The following information outlines the type of rear axle lubrication utilized in GM Truck axles.
I. Fluid Type
II. The 1500, 2500 and 3500 GMT 800 Trucks utilize SAE 75W-90 Synthetic Axle Lubricant. The GM part number is 12378261 and the specification is 9986115.
¨ Note: the recommended lube for HD trailer towing is a 75W-140 Synthetic Gear lube, part number12346140.
III. Inspection/Change Frequency
¨ The 1500 and 2500 GM Trucks recommend rear axle fluid level checks every 7500 miles. Fluid should be added as needed.¨ Under heavy duty trailer towing conditions the lube should be changed after the first 500 miles of towing. This is due to the extreme heat generated on break-in of the hypoid gear set."
[ February 13, 2003, 11:45 AM: Message edited by: Bill Plock ]
I can't answer your question about the Schafer's but I believe your Denali comes from the factory with Synthetic 75w90 GL5 Axel Lube and 9986115 is GM's spec for this lube.
I just bought some Mobil 1 75w90 Synthetic (6.99/Quart) for my 2003 2500HD Silverado and I understand the GM lube is about $25/quart at the dealer.
The following is some relevant info that was posted on another Forum I read
(my apologies if this is not allowed here).
"Here is some info Eaton sent me in the past:
GM introduced the new body style in 1998. At the same time they upgraded
the differential and changed to a synthetic lube. The G80 is specifically designed to give ultimate performance with this lube, and the lube contains special additives that help reduce slip stick that occurs between the clutches. the GM synthetic lube typically runs about 100+ degrees cooler than mineral base lube, which is better if you do allot of towing or heavy hauling. I would recommend that you stay with the GM synthetic, not Mobil 1. If you don't tow or haul you could use the pre 1998 mineral lube without
degrading performance of the differential. this would be a cheaper option but require more lube changes. " "Axle tolerances of the 1/2 ton trucks are very tight. The recommended procedure was to change lube after 500 miles of heavy towing, which would is considered a break in period. This breaking period generates high heat conditions in the axle which was found to degrade the synthetic beyond the point of mineral lube. After the 500 mile lube change, the axle is broke in and does not generate the high heat. If you use GM synthetic after the break-in period, it can be considered "lube for life", although some say to change it at 40,000 - 50,000 mile intervals." "If you don't tow, don't worry about the oil change as it a waste of money." "If your truck is pre 1998 or the old style, it comes with mineral lube. IN that case you need to stay with mineral because the seals are designed to work with it. If you changed from mineral to synthetic you'll cause your seals to swell and eventually leak. It's ok to go from synthetic to mineral because you won't cause swelling. many of your stop leak chemicals effect seals in this manner, resulting in a short term fix but a long term problem."
Back in November, I received the following:
"From Mr. Ralph Holmquist of Eaton, the maker of the locking differential:
"The maintenance schedule for the rear axle was developed by American Axle & Manufacturing and GM truck based on multiple tests. The Eaton locker does not require additional maintenance nor does it add heat to the lube. The lube will darken due to the carbon wear on the clutch surfaces, much the same as a disc brake pad & rotor. This does not damage axle components such as seals or bearings. However, a new axle can produce excessive temperatures (plus 350 degrees F) due to the ring & pinion breaking in that will break the lube additives down. Avoid high loads, trailer towing and high speed extended driving during the initial break in of the vehicle. After the break in period axle temps will level at a much lower figure. Lube changes are a good idea because the additives are replenished and contaminates such as casting sand are eliminated. The axle is filled at the factory with a synthetic 75w90 GL5 rating made by Texaco under part # 2276. The GM service # is 12378261. This is the only lube we have done extensive testing with to insure locker compatibility. The only negative to using one of these other lubes is an increased potential for clutch chatter. This really doesn't hurt anything and can be corrected by changing the lube. I noticed in the latest GM owners manual the term "or equivalent" when referring to the lube specification. Look for a GL5 rating on the bottle to make sure the ring & pinion, seals & bearings are protected. Limited slip additive is not needed." The following information outlines the type of rear axle lubrication utilized in GM Truck axles.
I. Fluid Type
II. The 1500, 2500 and 3500 GMT 800 Trucks utilize SAE 75W-90 Synthetic Axle Lubricant. The GM part number is 12378261 and the specification is 9986115.
¨ Note: the recommended lube for HD trailer towing is a 75W-140 Synthetic Gear lube, part number12346140.
III. Inspection/Change Frequency
¨ The 1500 and 2500 GM Trucks recommend rear axle fluid level checks every 7500 miles. Fluid should be added as needed.¨ Under heavy duty trailer towing conditions the lube should be changed after the first 500 miles of towing. This is due to the extreme heat generated on break-in of the hypoid gear set."
[ February 13, 2003, 11:45 AM: Message edited by: Bill Plock ]
I have a '00 Silverado and have also been unable to find specifics on that spec. I've used Mobil 1 w/o any problems. GM recommends you chnage the fluid every 50k miles or after 500 miles of heavy towing the first time. Just be sure and change it early the first time.
Thanks guys, I appreciate the help. Sounds like any GL-5 EP synthetic lube will do the trick, like the Schaeffer's #267 that I already put in. You'd think GM would let us in on the spec they require on the oil. At least we know that you can go and buy the Texaco lube for 1/3 the price of the GM part #. Someone told me the the GM cost $28. a quart!
If anyone does actually get a defination of that #9986115 Spec, let us all know!
Butch 02 Sierra Denali
If anyone does actually get a defination of that #9986115 Spec, let us all know!
Butch 02 Sierra Denali
I have a 2001 Burb with a G80 locker and got the same response from Eaton that gave Bill Plock. They confirmed that their G80's come from the factory with Texaco Syn 75-90 oil# 2276. However, when I went to the Havoline/Texaco website, could not find that product #. I did however find a product called Texaco Synstar GL 75-90. I attempted to post the link below.
Texaco Syn-Star® GL 75W-90
The big question is, is this the same stuff or a different formulation?
What do people think of this gear oil. I have 5 gallons that was given to me.
My manual and Eaton both promote synthetic gear oil over mineral base. But, I think that the Schaeffer 267 would work well too.
[ April 17, 2003, 04:33 PM: Message edited by: BOBISTHEOILGUY ]
Texaco Syn-Star® GL 75W-90
The big question is, is this the same stuff or a different formulation?
What do people think of this gear oil. I have 5 gallons that was given to me.
My manual and Eaton both promote synthetic gear oil over mineral base. But, I think that the Schaeffer 267 would work well too.
[ April 17, 2003, 04:33 PM: Message edited by: BOBISTHEOILGUY ]
OK, if you want to use a Full Synthetic gear oil in that unit, schaeffers 741 will be the one to use. It is an approved lubricant for Eaton. It will also most likely need the frictional additive used in addition with it.
The 267 will also work but is not a Full Synthetic. In some cases you may have to also add some frictional additive, depending on the application. The way to determine if you need this is if you experience any pop,chatter or moaning sounds when in a turn.
The 267 will also work but is not a Full Synthetic. In some cases you may have to also add some frictional additive, depending on the application. The way to determine if you need this is if you experience any pop,chatter or moaning sounds when in a turn.
- Status
