Tranny/XferCase/Diff Oil suggestions?

[bcobb]

Hello everyone, great forums!
I am very new to the Yukon Denali. I just bought a very nice XL with 48k on it. I'd like to change the tranny, transfer case and rear diff fluids. Can someone recommend to me the best fluids to put in (Redline/Amsoil...etc), I'm looking for something that works well with these cars as is possibly used by the majority with no issues. I'm assuming synthetic. I've also read some conflicting facts as to whether the factory used full synthetic or semi-synthetic. Also, would I need to do a complete flush and fill? I won't be doing any regular towing, just pulling the occasional utility trailer with a garden tractor or dirt bikes.
Thanks in advance!
-Bryan
2007 Yukon XL Denali

 

[BOSS]

Welcome brother, if you are servicing the tranny at 50k, keep it up at regular intervals. Last thing you want to do is change it and let it for 100k+ and then try and change it again, you could end up with a nice tranny problem on your hands. If you're considering a vette servo, do it before you hit 100k.

Oil is your preference, I like to use synth in the rear end and tranny for heat dissipation


B

 

[Conor]

As far as the fluid in the tranny and transfer case, you want to use the OEM fluid. I believe it is Dexcon 6 or something like that. As far as oil, if you want to go full synthetic, Mobile 1 is the best. =

DO NOT DO A TRANNY FLUSH, in some cases this can cause other issues to come up! All you want to do is a tranny drain and fill and a transfer case filter if anything. You are still early for a tranny service. Take a good look and smell off the tranny dipstick. If it still looks nice and red and doesnt smell burnt at all, I would leave it alone foe another 10K-15K.

 

[rogersinsel]

As far as the fluid in the tranny and transfer case, you want to use the OEM fluid. I believe it is Dexcon 6 or something like that. As far as oil, if you want to go full synthetic, Mobile 1 is the best. =

DO NOT DO A TRANNY FLUSH, in some cases this can cause other issues to come up! All you want to do is a tranny drain and fill and a transfer case filter if anything. You are still early for a tranny service. Take a good look and smell off the tranny dipstick. If it still looks nice and red and doesnt smell burnt at all, I would leave it alone foe another 10K-15K.

No he is fine. 50,000 is the first mark that GM recommends a/t fluid replacement. Since he does know the history of the SUV, changing the fluid makes perfect sense. By the time the a/t fluid smells burnt, your tranny is dead. Due to the fact that the power train is still under warranty, I would follow their instructions and have them service it. If you self service keep your receipts and notes and make sure whatever you do does not violate it.

 

[Conor]

No he is fine. 50,000 is the first mark that GM recommends a/t fluid replacement. Since he does know the history of the SUV, changing the fluid makes perfect sense. By the time the a/t fluid smells burnt, your tranny is dead. Due to the fact that the power train is still under warranty, I would follow their instructions and have them service it. If you self service keep your receipts and notes and make sure whatever you do does not violate it.

Thats a great point. A tranny service can never hurt, especially if you don't know if it has been done before.

 

[bcobb]

After further review (looking at my owners manual again), I'm not supposed to service the tranny fluid until 100k. Transfer case is at 50k. So I think I'll wait on the tranny and take care of the transfer case. I think you are right about using OEM fluid though. There are certainly instances to use OEM and then instances to not, from what I've read and have been told, I'm using OEM!

Thanks for all the responses guys! It's appreciated!
-Bryan

 

[Z15]

If you want to use AMSOIL lubes, I can recommend what to use.

I'm more than happy to offer AMSOIL at dealer wholesale (+/- 25% below retail) via the AMSOIL Preferred Customer Program to anyone interested in saving money. Please drop me a PM for more info if interested.

All my vehicle use AMSOIL, 2010 GMC Sierra, 2009 Cadillac CTS4.

 

[ProStreetCamaro]

Amsoil in everything