Stupid question, will 75w-90 gear oils that already have the LSD additive in them affect operation of the G80?? I assume the GM gear oil has no additive in it, but all the big name store oils have the additive. I was thinking of going with Redline and was wondering if their 75w-90NS would be better than their regular 75w-90. I realize the NS version is supposed to be for manual transmissions. I want the same oil for front and rear diffs.
Gear Oil for Silverado G80 Locker
- Thread starter Egghaus
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I think you'll be fine with those oils, just don't use the additive that you'd buy separately. I run Amsoil Long Life in the rear with my Detroit and it works perfectly.
I think you'll be fine with those oils, just don't use the additive that you'd buy separately. I run Amsoil Long Life in the rear with my Detroit and it works perfectly.
I would research the "NS" (NS for "no sulfur," I presume) because if it's for manual transmissions, it may be short some of the anti-wear additives needed for diffs. There is no trouble using 75W90 GL5 at both ends of the truck, unless it calls for a 75W140 in the rear (and even then, perhaps, depending on how hard you work the truck).
In general, there are oils (usually mineral) that have the LS additive and some oils that already have the correct friction characteristics for limited slips. You would NOT want to use the former in your G80 Eaton but there's no trouble using the latter.
In general, there are oils (usually mineral) that have the LS additive and some oils that already have the correct friction characteristics for limited slips. You would NOT want to use the former in your G80 Eaton but there's no trouble using the latter.
Originally Posted By: Egghaus
Stupid question, will 75w-90 gear oils that already have the LSD additive in them affect operation of the G80?? I assume the GM gear oil has no additive in it, but all the big name store oils have the additive. I was thinking of going with Redline and was wondering if their 75w-90NS would be better than their regular 75w-90. I realize the NS version is supposed to be for manual transmissions. I want the same oil for front and rear diffs.
You will be fine using a gear oil that has some LS additive in it in your G80. I ran RP MaxGear 75W-90( F&R actually )in 2 Silverados with the G80 and it performed just fine.
Stupid question, will 75w-90 gear oils that already have the LSD additive in them affect operation of the G80?? I assume the GM gear oil has no additive in it, but all the big name store oils have the additive. I was thinking of going with Redline and was wondering if their 75w-90NS would be better than their regular 75w-90. I realize the NS version is supposed to be for manual transmissions. I want the same oil for front and rear diffs.
You will be fine using a gear oil that has some LS additive in it in your G80. I ran RP MaxGear 75W-90( F&R actually )in 2 Silverados with the G80 and it performed just fine.
I find an article about the G80:
"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."
Here's another quote from a reputable source, which addresses the type of fluids, including minerals and synthetics:
"Automatic Locking Differential Lubricants. [Note from Michael Asmussen, Torque Control Products Division of Eaton Corp.] We recommend the following lubrications for our locking differentials:
1)Texaco 2276; Synthetic 75 W90; Gm Part # 9986115
2)Texaco 9622; Mineral based 80W90; GM Part # 9985290
3)Texaco 2080; Synthetic 75W140 (heavy duty applications); GM part # 9985991
Note - All of the above lubes are preblended with friction modifier. No additional modifiers are necessary or recommended. As far as other lubes are concerned, any standard GL 5 lube will work, but the units perform optimally with the three listed above.
"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."
Here's another quote from a reputable source, which addresses the type of fluids, including minerals and synthetics:
"Automatic Locking Differential Lubricants. [Note from Michael Asmussen, Torque Control Products Division of Eaton Corp.] We recommend the following lubrications for our locking differentials:
1)Texaco 2276; Synthetic 75 W90; Gm Part # 9986115
2)Texaco 9622; Mineral based 80W90; GM Part # 9985290
3)Texaco 2080; Synthetic 75W140 (heavy duty applications); GM part # 9985991
Note - All of the above lubes are preblended with friction modifier. No additional modifiers are necessary or recommended. As far as other lubes are concerned, any standard GL 5 lube will work, but the units perform optimally with the three listed above.
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I put redline 75w90 in my s10. It's just works fine. I email redline, and for the our locking diff the 75w90 (with Ns) it's the good oil. The article i post above just confirmed that.
Originally Posted By: NHHEMI
You will be fine using a gear oil that has some LS additive in it in your G80. I ran RP MaxGear 75W-90( F&R actually )in 2 Silverados with the G80 and it performed just fine.
It might actually be better. I started to get some chatter in my G-80 with Amsoil SVG, so I put in some GM additive, and the chatter stopped.
You will be fine using a gear oil that has some LS additive in it in your G80. I ran RP MaxGear 75W-90( F&R actually )in 2 Silverados with the G80 and it performed just fine.
It might actually be better. I started to get some chatter in my G-80 with Amsoil SVG, so I put in some GM additive, and the chatter stopped.
Originally Posted By: spaenaur
The axle is filled at the
factory with a synthetic 75w90 GL5 rating made by Texaco under part # 2276.
This is the only lube we have done extensive
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.
"Automatic Locking Differential Lubricants. [Note from Michael Asmussen, Torque Control Products Division of Eaton Corp.] We recommend the following lubrications for our locking differentials:
1)Texaco 2276; Synthetic 75 W90; Gm Part # 9986115
2)Texaco 9622; Mineral based 80W90; GM Part # 9985290
3)Texaco 2080; Synthetic 75W140 (heavy duty applications); GM part # 9985991
Note - All of the above lubes are preblended with friction modifier. No additional modifiers are necessary or recommended. As far as other lubes are concerned, any standard GL 5 lube will work, but the units perform optimally with the three listed above.
Thank you for posting that.
I think I will switch back to Factory oil when it is time to change
The axle is filled at the
factory with a synthetic 75w90 GL5 rating made by Texaco under part # 2276.
This is the only lube we have done extensive
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.
"Automatic Locking Differential Lubricants. [Note from Michael Asmussen, Torque Control Products Division of Eaton Corp.] We recommend the following lubrications for our locking differentials:
1)Texaco 2276; Synthetic 75 W90; Gm Part # 9986115
2)Texaco 9622; Mineral based 80W90; GM Part # 9985290
3)Texaco 2080; Synthetic 75W140 (heavy duty applications); GM part # 9985991
Note - All of the above lubes are preblended with friction modifier. No additional modifiers are necessary or recommended. As far as other lubes are concerned, any standard GL 5 lube will work, but the units perform optimally with the three listed above.
Thank you for posting that.
I think I will switch back to Factory oil when it is time to change
I've used Mobil 1 Gear lube for years in my vehicles. I've never had to add the GM additive - but I did on my 1987 Buick GN just for good measure. I've used M1 in that Buick, a Corvette and my trucks with no problems and they all have G80 diffs. I only started using Redline a few years ago. The Redline will be a much better fluid than the Mobil 1, but you can't go wrong either way. I'm a Mobil 1 and Redline guy.
Ok sounds good. It's a brand new truck so I want to change out the differentials around 1k miles to get the break in junk out.
FYI, the term "G80" is a RPO (Regular Production Option) number, not a type of traction aid. Over the past 30 years, it could be a plate type limited slip (Saginaw, Eaton) and cone clutch type limited slip (Borg warner/Auburn Gear) or the so-called "Gov-Lok," more correctly called the Eaton Locking Differential (it isn't really a true locker because it can be made to bias when it's ostensibly locked, but I digress). I believe GM has also started using the gear type AA (American Axle) limited slip as well in some recent applications.
In trucks, it's generally the Eaton "Locker" but S10s could have a plate type limited slip, as well as cars. The Eaton Locker doesn't need any special additive but the plate type limited slips may. As I said before, many synthetics have the friction characteristics necessary so as to not need a special additive.
By the way, Egghaus, you did not tell us what truck you have. Might have some bearing on "the case."
In trucks, it's generally the Eaton "Locker" but S10s could have a plate type limited slip, as well as cars. The Eaton Locker doesn't need any special additive but the plate type limited slips may. As I said before, many synthetics have the friction characteristics necessary so as to not need a special additive.
By the way, Egghaus, you did not tell us what truck you have. Might have some bearing on "the case."
Truck is a 2011 Silverado Z71 4X4 with the 9.5" 14-Bolt SF axle. It has a more robust Eaton locker than the 8.6" axle .
I changed out the factory GM oil in my diffs at 3K miles. Used Mobil 1 75W-90 Syn in both with no problems. I have an 08 Sierra with the 8.6" 10 bolt and G80 locker.
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