Just Purchased 04 Denali

[2quik]

Just Purchased an 04 Denali with 86k Miles. I want to changed the transfer case, differentials and Tranny fluids.

Which fluids should i use? Also how difficult is it to do myself? Thanks for your responses.

[Stevens03]

Not difficult at all, just time. And use what GM spec's or better. I like synthetics for the added protection.

[KMGZ400]

do not change the tranny fluid. itll tear up your tranny.

[177mph]

do not change the tranny fluid. itll tear up your tranny.

 

Huh? Is this true? I just changed mine recently - with the filter. Why is this the case?

[Black02Silverado]

Just Purchased an 04 Denali with 86k Miles. I want to changed the transfer case, differentials and Tranny fluids.

Which fluids should i use? Also how difficult is it to do myself? Thanks for your responses.

 

 

It is all straight forward to accomplish. You should might find some "how to" articles in the Tech Wiki section on this forum. The transfer case will require the Auto Trak II from the dealer, 2qts are needed. The rest you can pick up at any auto parts store. The axles came with synthetic and the transmission will like stepping up to dexron VI fluid.

 

Fluids of choice for the differentials, AMSOIL, Mobil 1, Redline, Royal Purple.

 

For the ATF just go to the local auto parts and pick up some dexron VI fluid. You will need about 12qts if you do a fluid exchange. If you are just dropping the pan and changing the filter then get 6qts.

[Black02Silverado]

do not change the tranny fluid. itll tear up your tranny.

 

Huh? Is this true? I just changed mine recently - with the filter. Why is this the case?

 

 

Most do not like to change out the fluid on a high mileage transmission because in most cases the transmission seems to go out shortly afterwords. I have found this to be true in my experience only when I changed out the fluid in a transmission that the fluid was really nasty and was high mileage. If the fluid is still nice and red and doesn't smell then you will not have any problems.

[Sly]

Just Purchased an 04 Denali with 86k Miles. I want to changed the transfer case, differentials and Tranny fluids.

Which fluids should i use? Also how difficult is it to do myself? Thanks for your responses.

 

Also change out your Power Steering fluid as well. I used Mobil 1 ATF instead of power steering fluid. Changing the fluid made a huge difference. I would also pick up a fluid transfer pump. It will make refilling the the transfer case and differentials much easier.

[Sly]

do not change the tranny fluid. itll tear up your tranny.

 

Huh? Is this true? I just changed mine recently - with the filter. Why is this the case?

 

 

Most do not like to change out the fluid on a high mileage transmission because in most cases the transmission seems to go out shortly afterwords. I have found this to be true in my experience only when I changed out the fluid in a transmission that the fluid was really nasty and was high mileage. If the fluid is still nice and red and doesn't smell then you will not have any problems.

 

 

x2 if the fluid is brown and burnt smelling you might have issues. If not change it out. I would not flush it. I would do a fluid exchange as shown in the how to sections.