GM Truck Club Forum banner
1 - 4 of 4 Posts

· Registered
Joined
·
6,957 Posts
Changed the fluid in the rear differential. The amount of fluid that I removed was ~2.25 quarts, and the fluid I put back in was ~3.25 quarts. I put fluid in until it ran out the fill plug. I wonder why the difference?

Used Mobil 1 75W-90 gear oil.
the 10.5 takes 3.25QT / 9.5 2.7QT .. now on filling with the vehicle LEVEL in warm weather fill to just below the fill hole. in cold weather fill to 1/2in below the fill hole. this fluid when hot expands.

since you drained out A QT less then you must have a leak. check the fluid every oil change for level and fluid color.
 

· Registered
Joined
·
6,957 Posts
Could be as simple as the position of the asymmetrical center section...turn it one way and it will displace more volume than if its turned 90*. Depending on its position when it was last filled...

A leak on a differential should show up pretty readily. Even an ounce will make a complete mess underneath a truck; let alone a quart.
there is a vent tube hose if it got very the fluid may have come out of it as another possible cause or maybe it was never filled to the proper level this can occur if the vehicle was not on level surface.
 

· Registered
Joined
·
6,957 Posts
Before this thread gets too far off topic:

I would like the opinion of some of the forum members as do they think that filling G80 8.6" differential on a 2013 SIlverado up to the fill plug is bad, good, does not matter?

Thanks.
I never seen a diff go bad from too much fluid. some say the seals could get damaged from pressure build up.

I know that if the vehicle is not level you can put 4.5 QTS in it . or put in 1 qt too little. if the front end is high you can overfill very easy.
 

· Registered
Joined
·
6,957 Posts
I was under the impression that differentials have some kind of venting system on them so too much pressure cannot happen.
the venting hose can over time get plugged up. when I had my frame crossmember replaced they crushed this hose / did not route it properly. I caught this the next day when I dropped the fuel tank and rustproofed the frame and the crossmembers. even with the diff being properly filled had I not caught this I would have had seal damage/leaks. this fluid expands alot when heating under use.

my front diff was factory filled too high and it was coming out the over flow .
 
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top