Transmission gets Mercon III or VI? What about the transfer case?

[WildernessJeep]

I'm confused.

2005 Yukon Denali, AWD with 110,000 miles on it.

I am trying to do the transmission flush, as per ScottyBoy's write up. Seems pretty straight forward, and in his writeup he uses Mercon IV (6).

Did the vehicle come with Mercon 3, and he is upgrading to 6, or has it had synthetic all along? Is one better for this vehicle? The auto parts guy tried to sell me Mercon 3, but I understand there is a tech bulletin from GMC for some VIN's to upgrade to Mercon 6, but not all.

This is all before I start on the transfer case, which I assume gets the same fluid as the transmission.

Opinions?

 

[Sasquatch]

Mercon is for use in fords. Dexron is GM.


I`d stick with dexron. I have an 05 yukon and when i changed my fluid i used dexron 6. 10,000+ miles since with no problems. I changed mine at around 55k miles.

 

[WildernessJeep]

Mercon is for use in fords. Dexron is GM.


I`d stick with dexron. I have an 05 yukon and when i changed my fluid i used dexron 6. 10,000+ miles since with no problems. I changed mine at around 55k miles.

Most fluids are both, I just said Mercon because it was easier to type than the whole Mercon/Dexron word.

Transfer case? 3 or 6??

 

[BRUTUS_T_HOG]

3 or 6 will be fine in the transmission.

If your vehicle has auto 4wd it requires auto trak 2 fluid, do not put atf in

 

[WildernessJeep]

3 or 6 will be fine in the transmission.

If your vehicle has auto 4wd it requires auto trak 2 fluid, do not put atf in

How many quarts do I need? Two??

 

[BRUTUS_T_HOG]

I would get 3qt. The t-case will take just over 2 qts

 

[Wake]

3 or 6 will be fine in the transmission.

If your vehicle has auto 4wd it requires auto trak 2 fluid, do not put atf in

4wd is not the same as AWD.

The 05 doesn't use AT2 fluid, it uses Dex3-E ATF.

 

[WildernessJeep]

4wd is not the same as AWD.

The 05 doesn't use AT2 fluid, it uses Dex3-E ATF.

See? That's the problem. Everyone has a different idea about what fluid to use. What is the ultimate source? Where would I go for the final authority and answer?

 

[BRUTUS_T_HOG]

Ok to clear it up I just took the time to look in the factory service manual. AWD takes dexron 6. Auto 4wd takes auto trak 2.

The ultimate source would usually be the owners manual

 

[WildernessJeep]

Ok to clear it up I just took the time to look in the factory service manual. AWD takes dexron 6. Auto 4wd takes auto trak 2.

The ultimate source would usually be the owners manual

I dont' have one. Dextron 6 it is. Thanks for the help!!

R