Rear differential fluid change on 2500HD GMC Denali

Just a quick video of me changing rear diff fluid on my GMC 2500 HD. Dealership here wants almost $200 for this. I do it for about 50 in about 10 minutes. Truck has about 33k on it. 6-7k of towing and about 500 miles off pavement. Manufacturer doesn’t specify an interval to change it. I usually do between 30-40k depending on how much I tow with it, never had any problems (had the same truck in last body style) Thanks for watching.

[@wayawolf1967]

Im 57 years old and I still chuckle when I hear that sound. You know the one. If anyone else is around I say EWWWW that one was wet ! LOL

[@unclebucksprojects1537]

😂

[@kennethbullchild6660]

Thanks i had to put 4 quarts of gear oil in the rear diff on Ram 2500 thought maybe it was to much but it filled good,your video confirmed that I didn't overfill

[@wayawolf1967]

There is a limited slip additive that should go in first. Its up to $17 now as of 11/7/2023. Sounds wrong but if you dont use it you will have chatter , larger turning radius and a "floaty" feeling in your steering on straight roads. Many years of experience speaking here. Both back wheels are forcing the truck to pull evenly. One has to give up for turning or just driving in general. Without the limited slip additive the clutch pack in the rear end can not operate properly.

[@unclebucksprojects1537]

I usually get the Mobil 1 LS 75W. I was under the assumption that covered that. I could be wrong though, have been many times before.

[@steveleston1848]

dam you made that look easy wish my 04 express 3500 had a drain plug.or doe's it?

[@wgyoungblood]

You overfilled the diff. Filling it to the bottom of the threads is overfilled. If you read the service manual it gives the spec.
For all 6.6L Duramax Diesel 2500HD Series applications and all 3500 Series applications, the proper level is from 17 mm to 21 mm (0.6 in to 0.8 in) below the bottom of the fill plug hole, located on the rear axle. Add only enough fluid to reach the proper level.

[@nickrasmussen3247]

What are the consequences of an overfilled diff?

[@wgyoungblood]

Early axle seal failure

[@jasonmorales1846]

@@nickrasmussen3247 also air in the oil.Which is not good.

[@kennethbullchild6660]

Will filling it to plug hole hurt diff ?

[@1duramaxhd]

@@wgyoungblood not true on these trucks. There a quart under filled from factory for fuel mileage.

[@chrismowry8969]

FYI there not all the same, I have a 2016 gmc 2500hd base model and there is no fill plug on the diff cover

[@unclebucksprojects1537]

That’s very interesting. You would think it would be cheaper for GM to only make one for all LML’s rather than dealing with two part numbers.

[@chrismowry8969]

@@unclebucksprojects1537 I agree, they also put different size ring gear depending on model. Who'd of thought...

[@JackDrenalin]

Was there a need for limited slip additive

[@unclebucksprojects1537]

Not to my knowledge, but usually that’s one of the only synthetic ones I can find. Have never had an issue running it so I just stick to it.

[@Mattcandy123]

I just changed mine for first time 160,000km lol 80,000km or pulling

[@briantruck2284]

My 1991 don't have a drain plug , hand to remove diff cover

[@artiemcbride629]

What a goof ball

[@TheOneStoneAngell]

So why does Banks Power recommend 4 quarts of oil, 75W140.

[@unclebucksprojects1537]

I guess you would have to ask Banks. Should be 75W 90 or the special GM 75W 85 (P/N- 19300457) unless they have changed something.

[@TheOneStoneAngell]

@@unclebucksprojects1537 Follow up: I recently changed the oil in my 2017 Duramax that had been previously changed by my GMC dealership. I was curious how much oil they used..... I came out to be almost 4 quarts. Anyhow I used Amsoil 75w90 Severe Gear oil..... very nice having a drain plug.

[@GarrettRC5thscaler]

4:16 lolololololol

[@unclebucksprojects1537]

Garrett R.C. Hahah.