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Axle lube for 2500 series

CarMech1969

Full Member
Joined
Jul 1, 2016
Messages
498
Location
Scarborough, ON
Good day all  :wave:

What gear oil do you guys use for your Avalanche?
Owner's manual says to use 80W90 in the front diff, and 75W90 synthetic in the rear.
Do I need to be concerned about the GM specs (a.k.a. 'grape juice'), or will any good axle lubricant do the job?

Thanks for any testimonials that you may have  :B:

CarMech1969
 
I use Mobil 1 products all around in my EXT.

(y)
 
I went with synthetic both front and rear. Just watch for leaks in the front diff if you do it.
 
Thanks everyone for the feedback  :cool:

In other news - had Passlock issues since water got into the truck Sunday night from a bad storm, due to a leaky windshield.

Did a relearn, and it started and ran. Hope it doesn't get stuck somewhere.

CarMech1969
 
Today I replaced the axle oil in the axles.
I used 75w90 synthetic in the rear axle, and 80w90 in the front, as called for in the owner's manual.
Took about 2 3/4ish liters for the rear, and almost 2 liters for the front.
The front axle oil looked like it was never changed, was black as coal, and the magnet was holding a lot of debris.
The rear axle oil didn't look too bad. Looked like someone was there before, as the plugs had tool marks on them. That happens when you forget to scrape any rust or dirt out of the square hole before putting a ratchet on it.
So that's all sorted now  :p

Still having Passlock issues though. Since the damn rainstorm, which caused water to leak all over my steering column and dash, I have this 'Security' light that remains on even after the truck starts.  ???
It has an aftermarket remote start, with the associated rat's nest of unsoldered wiring. Not too pleased with finding that mess.

Anyhow...to be continued.

CarMech1969


 
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