Front/Rear/Transfer Case/Tranny Fluids

[bikerglasses]

Owners Manual says:

Front
80w-90 axle lube

Rear
75w-90 synthetic axle

Transfer case
Auto-trak II fluid

Auto Tranny
Dexron-III


What's the alternatives. I'd like to change to full synthetic fluids on all if possible. Last owner was pretty good on all, I think he had everything done around 75-80k. It has 107k now, I bought it with 105k.


Thanks,
Ian

 

[doylee4693]

asking an oil reated question on an auto forum is going to give you all kinds of answers.Ive had around 13 cars and trucks and everytime I switched the axle fluid with synthetic oil, I would get a leak within the following 15000 miles or less.I only use the same stuff that came with truck and the same stuff that got you to 107k.JMHO

 

[WildBill]

The only must is if you have an Autotrack transfer case (it says "Auto" on the 4x4 panel) you have to use the Blue fluid from GM, Auto Track II. THere are clutches in there that need that fluid to work right.

I dont think the others matter. I used Mobile 1 engine oil for 15+ years with no problems.

FWIW, i switched to Mobile 1 Synthetic in the rear end 6mo ago, and now it leaks a bit...maybe Doylee is right!?

 

[domin8]

Dex 6 is the synthetic version of Dex 3. Do some research, but I believe you can use them interchangeably. As for the others, stick with what it came. Just be sure to get quality stuff. Using the off brand stuff doesn't protect as much as the name brand.

 

[hidpositive]

im about to be doing a 60k on my 06 denali soon and plan on using all oem fluids...partially because the dealership i work at owns a chevy store too so can get the stuff for very cheap. not sure if i should be replacing a trans filter too, ill figure that out when i get closer to that 60k mark. Im about to roll over like 48k in the next week or so.

-Gary

 

[Sasquatch]

All three of my trucks were bought used. I switched all of them over to synthetic engine, diff, and transmission fluid and have had zero leaks as a result in over ten years.

I just flushed the transmission and changed the filter in my 05 yukon at 60K with dex vi. I flushed it using the method explained in this writeup and it worked great. http://www.truckmodcentral.com/forums/showthread.php?t=4699

I run royal purple 75-90 in the front and rear differentials. Front takes 1.8 quarts and the rear 2.75 quarts.

 

[bikerglasses]

Does about 9ozs of oil left sound right? I was pumping it in and started overflowing.



Sent from my SCH-I535 using Tapatalk 2

 

[bikerglasses]

Drove around block took bolt off to check again and oil came pouring out.

Should I pump some out?

Sent from my SCH-I535 using Tapatalk 2