mobil gear lube

[sm]

Hello everyone this is my first post and just want to say that i really enjoy this forum and lots of good info here.
1998 GMC Sierra 4X4
I`m going to change both the front and rear diff. lubes.
For the front i`m thinking of Mobilube SHC 75w-90.
For the rear diff it has the G80 option and i need to think about the LS. Am i correct that the SHC is not the best for this diff with the limited slip?
I found 2 different mobil 1 75w-90 gear lubes.
Here are the links for you to look.
http://www.mobil.com/USA-English/Lubes/PDS/GLXXENPVLMOMobil1_75W-90_SyntheticGearLubricant.asp
and...
http://www.mobil.com/USA-English/Lubes/PDS/GLXXENPVLMOMobil1SyntheticGearLubricant.asp

So what i`m asking is there a difference between the 2??? The specs seem to be identical.
I am also dealing with the local Esso dealer so i should be able to get all of this stuff there.
Thanks in advance for your advice!
stephen

 

[heyjay]

The first link is the "updated" Mobil 1 Gear Oil 75W-90, which is essentially the same as the "old" Mobil 1 Gear Oil.

You should not have to use any additional additives running Mobil 1 Gear Oil in your G80 rear axle.

I made the mistake of filling with Exxon SGO 75W-90, a commercial gear lube similar to Mobil MobilLube SHC 75W-90. The G80 in my 2000 GMC stopped working, though with patient flushing on an approved gear lube and lots of LS additives, it came back to life.

You will find the MobilLube SHC 75W-90 will improve the engagement of your front axle in very cold weather.

Jerry

 

[Doug Hillary]

Hi,
in Australia the following applies;

Mobil SHC 75w-90 GL5 is unsuitable in LSDs

Mobil 1 75w-90 GL5 IS suitable for LSDs

These are both excellent and cost effective lubricants that I use in extended drains out to 1 million+ kms

I hope this helps

Regards

 

[wtd]

I use Mobil 1 75W-90 gear lube in the front and rear differential on my 98 chevy 4x4 with no problems and have been using it for the last 40,000 miles. I also have the G80 rearend.

Wayne

 

[heyjay]

Doug thanks for the post. Outside of North America Mobil refers to both gear oils as "SHC 75W-90" so it can be a bit confusing. One is intended for HD truck axles and extended drains/warranty, the other for consumer use.

To avoid confusion on the issue, let's go over the two products. Here in North America you can buy:

Mobil MobilLube SHC 75W-90: This is a commercial synthetic GL-5 gear oil intended for extended warranty and extended drains in HD truck axles you find in Kenworth, Peterbilt, Mack, etc. It meets the Eaton Dana E500 specs, the Mack specs, and the Navistar specs. Do NOT use it in a light-duty truck with a limited slip unit.

Mobil 1 Gear Oil 75W-90: This is a consumer synthetic GL-5 gear oil intended for passenger cars and light duty trucks. It contains the proper additives to work fine in most limited slip applications without needing extra additives. This product is not intended for, and should not be used in, HD commercial truck axle applications.

The GM light truck axles with the G80 option code "locker" is actually the original GovLok: there are clutch plates inside that are actuated by the flyweight governor sensor that engages a cam to drive the plates together. So the oil must contain proper LS additives.

You should be fine running Mobil 1 Gear Oil 75W-90 in your G80 axle. It's also fine to use in your front axle too.

Did you already purchase the Mobil MobilLube SHC 75W-90? As far as I know, the smallest container you can buy it in is a 20 litre pail. That could be a bit awkward to keep around just for your front end: you could service the front axle every fall and the pail would last 10 years!

If you're looking for a cheaper alternative to your front axle, and you want the low temp performance, ask your Esso dealer about Esso Gear Oil GX Extra 75W-90. This is a partial synthetic GL-6 rated gear oil designed for HD applications in cold temps. Much cheaper than the Mobil MobilLube SHC 75W-90. Do not use it in your G80 though.

Jerry

 

[sm]

Thanks Jerry for your breakdown about these 2 products.
I have not purchased the gear lube yet but i was in talking with the guys at the Esso shop and i saw the 4L jugs of Mobilube SHC 75-90 there. If it was only available in 20L pails i would not be buying it!! I want to pick up the Mobil 1 and the SHC soon to change in April (hopefully no snow left!!!)
I`m also going to try the XD3-extra 0-30 next winter..looks like a good product

 

[S2000driver]

quote:

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Originally posted by heyjay:

Mobil 1 Gear Oil 75W-90: This is a consumer synthetic GL-5 gear oil intended for passenger cars and light duty trucks. It contains the proper additives to work fine in most limited slip applications without needing extra additives.
Jerry

---

Thanks Jerry for chiming in with such a thorough answer.

I just bought a case of 12 quarts of M1 75W90 GL-5, and I was getting nervous maybe I got the wrong product for a Torsen-2 rear diff! I was going to go down to the basement and look all over the bottles for SHC

 

[RavenTai]

quote:

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Originally posted by S2000driver:

quote:

---

Originally posted by heyjay:

Mobil 1 Gear Oil 75W-90: This is a consumer synthetic GL-5 gear oil intended for passenger cars and light duty trucks. It contains the proper additives to work fine in most limited slip applications without needing extra additives.
Jerry

---

Thanks Jerry for chiming in with such a thorough answer.

I just bought a case of 12 quarts of M1 75W90 GL-5, and I was getting nervous maybe I got the wrong product for a Torsen-2 rear diff! I was going to go down to the basement and look all over the bottles for SHC

---

not sure what torsen-2 is but a torsen (tourque sensing) diff is an all gear solution no clucthes so no limited slip addative needed

 

[heyjay]

quote:

---

Originally posted by sm:
Thanks Jerry for your breakdown about these 2 products.
I have not purchased the gear lube yet but i was in talking with the guys at the Esso shop and i saw the 4L jugs of Mobilube SHC 75-90 there. If it was only available in 20L pails i would not be buying it!! I want to pick up the Mobil 1 and the SHC soon to change in April (hopefully no snow left!!!)
I`m also going to try the XD3-extra 0-30 next winter..looks like a good product

---

Did you say 4 litre jugs?? That would be a LOT handier for the consumer! You can even buy one of those little oil pump contraptions to fit into the bottle and quickly service your front end.

Geez, my local Esso dealer only stocks it in 20 litre pails, drums, and can order in totes. I'll have to ask him about the 4 litre jugs, as a few local folks have been put off wanting to use MobilLube SHC in the front axle of their GM trucks since they have to buy a 20 litre pail.

Jerry