2021 RWD Denali Differential Service recommendations...

[JasonHTX]

Is there a recommended service interval on the differential?

 

[wjburken]

Is there a recommended service interval on the differential?

I see that the manual for you vehicle doesn’t list the rear diff, but I’d recommend going with 40K-45K.

 

[Blackcar]

Is there a recommended service interval on the differential?

If you get in glove box in owner's manual there is a list of service intervals and a section of recommended fluids and parts numbers.

 

[JasonHTX]

If you get in glove box in owner's manual there is a list of service intervals and a section of recommended fluids and parts numbers.

Yeah, did that and double and triple checked -- doesn't mention a thing about differential. Have you read the manual?

 

[WalleyeMikeIII]

Yeah, did that and double and triple checked -- doesn't mention a thing about differential. Have you read the manual?

He’s right, not a single mention of fear diff maintenance in the maintenance schedule. I suggest around 45k, when you do the transmission fluid and filter.

 

[Blackcar]

If they changed the 2021 manual maybe but this is out of my 2017 owner's manual page 388. now they could have changed what fluid that is used is yours.

2017 GMC Yukon Owner's Manual PDF (Page 388 of 429)

ownersmanuals2.com

 

[wjburken]

If they changed the 2021 manual maybe but this is out of my 2017 owner's manual page 388. now they could have changed what fluid is used is yours.

2017 GMC Yukon Owner's Manual PDF (Page 388 of 429)

ownersmanuals2.com

As has been mentioned already, it is not in the manual for the 2021.

 

[Blackcar]

He’s right, not a single mention of fear diff maintenance in the maintenance schedule. I suggest around 45k, when you do the transmission fluid and filter.

I see that they are not wanting owner to work on vehicle after years of specifications being put in owner's manual crazy.

 

[WalleyeMikeIII]

I see that they are not wanting owner to work on vehicle after years of specifications being put in owner's manual crazy.

You can always buy the service manual, or subscribe to Alldata. It is tough these days, you need access to all the computers and calibrations (firmware for the various modules) in order to work on your ride.

Agree though, I find it really odd they don't have rear diff service, esp in the "Severe" service section. As I understand it though, there is not even a drain plug on the rear diff, so its a remove the cover, replace the gasket, clean it all out, and refill scenario.

I tow a lot (not real heavy, 4500lb boat), but about 25-30% of my miles. So I get the whole driveline on all my trucks done at the transmission service interval. My service manager says I may be a bit overzealous on the front and rear diff service, but he says the transfer case service is a must (not applicable for you, since you have 2WD), as there is onlly about 1.3 qt in the T-Case.

 

[WalleyeMikeIII]

As has been mentioned already, it is not in the manual for the 2021.

Even in the 2017 Manual, there is no specified service interval for the rear diff, only specifies what fluid to use...Honestly, I don't ever recall seeing rear diff service listed in the maintenance schedule for any of the light duty Full Size GM trucks I have owned, including the 2004 and 2013's.

 

[JasonHTX]

Thanks fellas. Great info and much appreciated!

 

[jforb]

Even in the 2017 Manual, there is no specified service interval for the rear diff, only specifies what fluid to use...Honestly, I don't ever recall seeing rear diff service listed in the maintenance schedule for any of the light duty Full Size GM trucks I have owned, including the 2004 and 2013's.

It's listed in the owners manual for my 1959 pickup....change it at first 1000 miles, then every 10,000 miles. As late as the late 1980s, they recommended frequent oil changes in the axles of 4x4s when used in severe service such as dusty or towing. Seems that they relaxed the requirements during the 1990s, when they switched to synthetic gear oil. The 1999 owners manual has no mention of changing.

 

[Stbentoak]

And for the record... what are the correct fluids and capacities for the 21+ models?

 

[jforb]

Per the Owner's Manual...."See your dealer".

I'd look in the service manual, but it doesn't seem to exist.

 

[Jonmurphy]

If you get in glove box in owner's manual there is a list of service intervals and a section of recommended fluids and parts numbers.

You need to cut the service recommendation in half at least especially when new change it at 10,000 miles make sure it has a magnetic plugged in it and then you can go for maybe another 20 or 30,000 miles that way at 300,000 miles You need to cut the service recommendation in half at least especially when new change it at 10,000 miles make sure it has a magnetic plugged in it and then you can go for maybe another 20 or 30,000 miles that way at 300,000 miles you are still being great

 

[WalleyeMikeIII]

You need to cut the service recommendation in half at least especially when new change it at 10,000 miles make sure it has a magnetic plugged in it and then you can go for maybe another 20 or 30,000 miles that way at 300,000 miles You need to cut the service recommendation in half at least especially when new change it at 10,000 miles make sure it has a magnetic plugged in it and then you can go for maybe another 20 or 30,000 miles that way at 300,000 miles you are still being great

Did you read the thread….already stated there is no stated service interval for the rear diff in the owners manual. Also, there is no drain plug on the rear diff, so a mag plug is not an option.

 

[clogan2]

FWIW, my brother's '03 2500 Silverado has never had tranny or diff fluid changed, now at nearly 350,000 miles. (He's wasn't big on maintenance). Shop told me at this stage, a transmission fluid change would likely result in a transmission failure.

 

[Pertzbro]

FWIW, my brother's '03 2500 Silverado has never had tranny or diff fluid changed, now at nearly 350,000 miles. (He's wasn't big on maintenance). Shop told me at this stage, a transmission fluid change would likely result in a transmission failure.

Yeah i wouldnt touch it until it blows. Then full rebuild.

 

[WalleyeMikeIII]

FWIW, my brother's '03 2500 Silverado has never had tranny or diff fluid changed, now at nearly 350,000 miles. (He's wasn't big on maintenance). Shop told me at this stage, a transmission fluid change would likely result in a transmission failure.

Thats awesome...and also likely rare; or rarer w/ these more new fangled, "modern" versions...

Does that vintage 2500 have an Allison?

 

[clogan2]

Thats awesome...and also likely rare; or rarer w/ these more new fangled, "modern" versions...

Does that vintage 2500 have an Allison?

It's a gas engine.