Rear differential level on 2024 3500 L8T

[64BAwagon]

I searched for the discussion from a while back where we discussed the level of gear oil in our new trucks. Personally I added a full qt to bring my diff to the level prescribed by GM in their service instructions on this model (min of .4" or 10mm from bottom of fill hole) 

I wanted to share my experience further since I just completed servicing the rear diff on my truck. It now has about 5200 miles on it with around 3000 of those miles pulling a 5th wheel and cargo weighing around 13k. 

I removed the cover and wiped out the bottom of the housing. I then cleaned the cover and wiped the sludge off of the magnet (seemed typical for a new truck) 

It then took exactly 4 qts of fluid to fill the diff to the correct level. I even went so far as to drain the remaining fluid from the jugs and then put the last 16 oz or so in with a fluid hand pump I have. Very little was wasted. 

I just wanted to share the quantity info since it had been discussed before. I tried to find the old thread but couldnt along with the service document I know I save but I couldnt find either one. 

 

Scott

[64BAwagon]

I did find the last image from the document and it shows the approximate volume of the diff and lists it at 3.18 qts. 

This seems to contradict what it actually takes to fill that diff to the level GM indicates and would explain why many of us needed to add almost a qt to bring the new trucks up to the GM specified level. 

I do know that American axle and GM were made aware of this discrepancy. Where it went from there is unknown. I doubt without any documentation from dealer service depts it likely got blown off as an American axle issue since they are filled by AA at the end of their production. 

Edited April 11 by 64BAwagon

[Capt Bob]

I also put in a quart in the rear pumpkin using my pump.

Put less than a pint in the front diff.