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GM synthetic gear oil

pm26

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pm26 Senior Enthusiast

pm26

Posted
Posted

I just bought a quart of GM differential gear oil (75W90). The cost was over $ 21/quart, with the list price supposedly over $ 27! Are these guys out of their mind? Mobil1 and Redline synthetic gear oils are about $9/quart, and are just as good or better than this stuff. However, I just needed to add a little oil, so I did not want to mix brands.

 

I am only posting this so that if you replace your rear end oil and go your friendly GM dealer to buy 3 quarts, you do not faint when you hear what it costs.

 

Note: As I said, Mobil 1 or Redline are my first choices. At a reasonable price. What I did, I checked the differential oil level, and it was about 1.5 inches below the bottom edge of the filler hole (lower end of the factory spec). I added about 0.4 quarts of oil, which brought the level up to about 0.6 inches below the filler plug opening (upper limit of the factory spec. 0.6 to 1.6 inch range looks odd to me.

 

The GM part number for this oil is89021677(lubricant 8.800). The list price is $ 27.55 per quart, my price was $ 20.67/quart, or $21.91/quart with tax. The only more expensive gear oil I ever bought was Sea Doo oil for my jet ski jet pump housing. It was something like $ 10 for a 4 ounce bottle.

the blur Enthusiast

the blur

Posted
Posted

that's pretty exact measurments their. 0.6 " how exactly did you do that? with a veriner caliper ? or a micrometer?

mmmikkke Senior Enthusiast

mmmikkke

Posted
Posted

Maybe it's a metric conversion. That range would equal 1.5 to 4 cm. Seems a lot easier to swallow that way.

100R1 Enthusiast

100R1

Posted
Posted

Last I looked GM does not own any oil fields, refinerys or even a partnership in any.

 

The grape juice is done by someone else to GM's specifications and repackaged into a nice GM container. As long aqs you meet the MinimumGM requirements for the lube and supplied by any manufacture you will not have any problems.

 

With that said I favor Redline and Mobil 1 products

 

As far as measuring the amount of fluid in your diff.. Take a allen wrench and use that to check the level (more accurate than the old finger method). I have both Metric and good old American "inch" vaneer calipers I use to measure things like this.

 

I wish we would have grown up in the metric world, It's a lot easier than dicking around with fractions and decimals!

05Quadrasteer Enthusiast

05Quadrasteer

Posted
Posted

Becareful using other than GM oil in the rear differential. This may only be true with the Quadrasteer but every time other than the recommended GM oil was put into it the vehicle has problems. If you want to check out what I am talking about visit quadrasteerclub.com There is a whole discussion about the proper oil in the rear differential.

 

Have a nice day.

 

Bill

bigdogxx Enthusiast

bigdogxx

Posted
Posted
mobil 1 gear oil does not claim to meet the GM spec. So i bit the bullet and bought 3 qts.  It cost almost 70$ to put gas in it so whats another 70$. :D

 

 

 

 

That is a good point and very true, i blink and before i know it my gas tank has sucked 60+ dollars out of my wallet! :banghead: So 70 bucks for maintance of the rear end isnt really that pricey considering it will last a couple years atleast in my case before needing to change it out again.And really anything weather it be a ford,toyota,nissan,bmw,meredes ect ect there is always a mark up on anything dealer related this is no big surprise atleast not to me.

pm26 Senior Enthusiast

pm26

Posted
  • Author
Posted
mobil 1 gear oil does not claim to meet the GM spec. So i bit the bullet and bought 3 qts.  It cost almost 70$ to put gas in it so whats another 70$. :banghead:

 

 

 

 

 

Do you know what is different about this GM oil? I hope that do not have a different part number just for locking diferentials.

Bish Senior Enthusiast

Bish

Posted
Posted
You're crazy to pay that.  Get you some Mobil 1 and be done with it.

 

 

 

 

Agreed. Going on 165K with about 30K of towing (5000lbs). Nothing but Mobil 1 since first 500 miles of towing. Every time I clean and inspect, I wonder why I'm changing it since it looks so clean :chevy:

pm26 Senior Enthusiast

pm26

Posted
  • Author
Posted
You're crazy to pay that.  Get you some Mobil 1 and be done with it.

 

 

 

 

Agreed. Going on 165K with about 30K of towing (5000lbs). Nothing but Mobil 1 since first 500 miles of towing. Every time I clean and inspect, I wonder why I'm changing it since it looks so clean :chevy:

 

 

 

 

 

When did you start using mobil1 in your truck?(At what mileage)

Mighty HD Senior Enthusiast

Mighty HD

Posted
Posted

i changed everything but the trans/transfer case to mobil 1 @ 400 miles.

 

The rear end has been just fine. No way in hell I'm paying their price for oil. It has stayed much cleaner as well which leads me to believe less wear?

 

i've got 15k on it now....

Bish Senior Enthusiast

Bish

Posted
Posted
You're crazy to pay that.  Get you some Mobil 1 and be done with it.

 

 

 

 

Agreed. Going on 165K with about 30K of towing (5000lbs). Nothing but Mobil 1 since first 500 miles of towing. Every time I clean and inspect, I wonder why I'm changing it since it looks so clean :chevy:

 

 

 

 

 

When did you start using mobil1 in your truck?(At what mileage)

 

 

 

 

 

Changed out the stock fluid at about 5,000 miles after my first 500 miles of towing (as recommended). Changed it every 40-50K after that.

pm26 Senior Enthusiast

pm26

Posted
  • Author
Posted
As long as you put in pure synthetic 75W90 gear oil from a quality manufactuer you're ok.

 

 

 

 

So what is this talk about Mobil 1 not meeting the GM spec? Is this just hearsay? Does Redline oil meet the GM spec? Both Mobil1 and Redline fully synthetic 75W90 gear oil are priced about the same : about $ 9/quart

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