• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Synthetic Gear Oil And Regular Gear Oil Mixed

BIGR

BIGR

Lucky To Be Here
Messages
10,995
Reaction score
16,525
Location
Appalachian Mountains
Just wondering if mixing 75W-90 Synthetic Gear Oil and GM Gear Oil is going to cause any problems. Here is my ordeal. Due to the bad weather and me feeling like I have the flu I decided to fork out the money and let the dealer change my oil, oil filter and fuel filter. I had set up an appointment for today since I was not working. Earlier in the morning I had been at the tire place to get my new tires balanced again and the nice tire guy informed me that the left rear axle seal was leaking on my truck. I thanked him and since I was headed to the dealer at 11 AM I decided I would get it checked out. I went to the dealer and provided my own oil and filter. They were nice enough to do that and also changed my fuel filter (13217 miles on same). I also asked the service writer to get them to check the axle seal and if possible go ahead and fix it. The left rear seal was leaking and they took the extra time and fixed it for me. I noticed they did add 1 (I would assume 1 bottle of lube (grape juice) at $35.08). Since I had replaced the factory gear oil many miles ago with Shell 75W-90 Synthetic Gear Oil I am now thinking I have roughly 3 quarts of the Shell oil left plus the 1 quart of dealer supplied oil. My question to you guru's is how compatible will this combination be? Should I just run it and not worry about it or drain it out in the near future and replace with 75W-90 synthetic gear oil?
 
Just curious, did you pay for having the rear seal changed? Cause I just had mine changed on the pass. side along with the drivers side front hub and it was all covered under the 5yr/100,000 mile powertrain warranty.
 
I paid the following for it. Parts: $81.92 Labor: $126.00 for a total of $207.92

I wouldn't sure if the powertrain warranty would cover that, I guess the dealer didn't think so. I have to say that one service writer has helped me out in the past and I would think that if he thought he could get by with it he would have tried to cover it under warranty.
 
Yeah, the dealer I went to here in San Antonio, TX had some kind of cheat sheet I am trying to get that list everything that is covered in that powertrain warranty.
 
That would be some great info to have. I wonder sometimes if the dealer lets some of the warranty items slide by, since GM is in such a crunch. If nobody questions them about it being covered then they just charge you.
 
1) 2006 isn't covered on the 5yr/100k full powertrain warranty that was added in mid '07. That was only '07 & up. Only 5yr/100k for the diesel powertrain package and IIRC that doesn't include seals.
2)The grape juice synthetic will mix just fine with the Shell synthetic. As long as both are synthetic you are good.
 
According to the dealership I went to they replaced the rear seal and front hub assembly under that powertrain warranty.
 
But you have an '07 Steve. His is an '06 like mine. We didn't get the big warranty. Got it on the wife's Tahoe though.
 
A friend of mine has an 06 that is covered under the 100k 5 year warranty. I'm not sure but I think it depends on when you took delivery.
 
You must log in or register to reply here.
Back
Top