2014 Yukon XL Denali

[2003DenaliXL]

What type of fluid is recommended for rear differential on my 2014 Yukon Denali.
Is this a good choice?

https://www.autozone.com/greases-an...75w-140-synthetic-gear-oil-1-quart/706574_0_0

TIA.....want something I can P/U locally.

 

[2003DenaliXL]

What type of fluid is recommended for rear differential on my 2014 Yukon Denali.
Is this a good choice?

https://www.autozone.com/greases-an...75w-140-synthetic-gear-oil-1-quart/706574_0_0

TIA.....want something I can P/U locally.

or this?

https://www.autozone.com/greases-an...l-1-75w90-synthetic-gear-oil-1-quart/1437_0_0

 

[wsteele]

If you look in your owners manual, it will call out the lube spec. I think 75W90 to the GM spec is what they likely call out. I think maybe the Denali has a limited slip rear end, if so, they may also call out a limited slip additive.

You will get lots of opinions about different weights. I always go with what GM says with my truck, seems to work OK.

 

[2003DenaliXL]

If you look in your owners manual, it will call out the lube spec. I think 75W90 to the GM spec is what they likely call out. I think maybe the Denali has a limited slip rear end, if so, they may also call out a limited slip additive.

You will get lots of opinions about different weights. I always go with what GM says with my truck, seems to work OK.

Think I will go with the 75W90 and this additive:

https://www.autozone.com/greases-an...limited-slip-gear-oil-additive-7-oz/17352_0_0

 

[swathdiver]

What type of fluid is recommended for rear differential on my 2014 Yukon Denali.
Is this a good choice?

https://www.autozone.com/greases-an...75w-140-synthetic-gear-oil-1-quart/706574_0_0

TIA.....want something I can P/U locally.

Tony, 75W90 full synthetic is what it calls for. You do not need limited slip additive. What does matter though is the capacity, if you have an AWD Denali, it will take 2.15 quarts and if you have a RWD Denali, it will take more, fill to about a finger nail below the fill hole (15-40mm).

 

[2003DenaliXL]

Tony, 75W90 full synthetic is what it calls for. You do not need limited slip additive. What does matter though is the capacity, if you have an AWD Denali, it will take 2.15 quarts and if you have a RWD Denali, it will take more, fill to about a finger nail below the fill hole (15-40mm).

It's AWD Denali......so no benefit to the additive? Is there any harm in using the additive?
This is for the rear........

 

[intheburbs]

You don't have a limited slip differential, so you don't need the additive.

 

[2003DenaliXL]

You don't have a limited slip differential, so you don't need the additive.

Thanks....

 

[Foggy]

On the RPO sticker in glovebox you can find your options codes
If it has G80 listed, then yes you DO have limited slip rear diff
Most of the synthetics have a limited slip additive built in, so
you don't have to worry too much about it.. But technically you should
add the limited slip additive if you have RPO G80 listed

 

[intheburbs]

On the RPO sticker in glovebox you can find your options codes
If it has G80 listed, then yes you DO have limited slip rear diff
Most of the synthetics have a limited slip additive built in, so
you don't have to worry too much about it.. But technically you should
add the limited slip additive if you have RPO G80 listed

The G80 is not a limited slip. It's a locker. It doesn't have the clutches that have to slip on every turn. So it doesn't need the friction modifier because you won't have any clutch chatter.

The G80 acts like an open differential. But when one wheel slips and the difference in wheel speeds exceeds 100 RPM, it locks. Once traction is restored, it unlocks.

This video illustrates the difference between the G80 and a typical limited slip.

 

[2003DenaliXL]

G80 confirmed...........no additive will be used.

Thanks!

 

[Matthew Jeschke]

The G80 is not a limited slip. It's a locker. It doesn't have the clutches that have to slip on every turn. So it doesn't need the friction modifier because you won't have any clutch chatter.

The G80 acts like an open differential. But when one wheel slips and the difference in wheel speeds exceeds 100 RPM, it locks. Once traction is restored, it unlocks.

This video illustrates the difference between the G80 and a typical limited slip

It has clutches. I took mine apart. They apply first when there is a differential then if differential exceeds a certain value the mechanical locker engages.

Rear Axle G80 Differential Rebuild | offroadTB.com

offroadtb.com

I think synthetic 75w80 includes a friction modifier but cannot seem to confirm. Manual appears to call for 75w80

 

[intheburbs]

It has clutches. I took mine apart. They apply first when there is a differential then if differential exceeds a certain value the mechanical locker engages.

Rear Axle G80 Differential Rebuild | offroadTB.com

offroadtb.com

I think synthetic 75w80 includes a friction modifier but cannot seem to confirm. Manual appears to call for 75w80

Wow, nice gravedigging.

Yes, the G80 has clutches. No they don't apply "first." The G80 is either locked, or it's not. There's no middle ground. When you make a turn in a truck with the G80, the differential acts like an open differential. The clutches only come into play if the G80 locking mechanism is tripped. That is why the G80 does not require friction modifiers in the gear oil.

In a traditional limited-slip differential, every time you turn the clutches have to slip against each other. Without the friction modifier, they'll chatter.