ATF Fluid which one

[Majja13]

Ok I know I need Dex VI, is there a recommend brand for this. AC Delco, Valvoline etc.

One more question what is the recommended fluid that you all use on your differentials I need to change this also just not sure what to change it too.

Thank you
Matt

[Majja13]

Thanks for the info and quick response. Turtle thanks for the light reading will get on it when I get home form work tonight.

[Turtle_n_Peeps]

As has been said before Dex 6 is Dex 6 is Dex 6. It's all the same.

As far as the gear lube goes; here is a good paper to read about gear lubes. Link A lot of surprises for me reading this paper.

After reading this report I would probably get Amsoil or Mobil 1 to stick in my rear end. :B Did I just type that? :B

[srt20]

I actually checked into this but it was for ATF+4 fluid. Turns out the every single brand of ATF+4 is exactly the same. So the quart that is $5 is the exact same as the name brand quart that is $15.

Maybe something you want to check into with the GM stuff.

[is_it_friday_ye]

I used Catrol ATF+4 in my Dodge but here is your Dextron VI. I ordered from Amazon and with prime, it was the best price I could find anywhere.

Dextron fluid

[MARKW8]

The problem with GMs spec is if you have the G80 locking differential. It doesn't get the older limited slip additive. It's very hard to find the 75w90 that doesn't include it.

Mark

[Campfire_Time]

MARKW8 wrote:
I don't think any aftermarket gear lube meets GM specs for late model trucks.

Mark

That would not surprise me. I've read on some GM forums that most folks go to dealer for their gear oil.

[coolbreeze01]

With a little research, I think you'll find that Mobil 1 will be just fine in your GM product.

You may even find a TSB about using 75W-90 in low temp areas.

[MARKW8]

I don't think any aftermarket gear lube meets GM specs for late model trucks.

Mark

[Majja13]

Campfire Time wrote:
Just for clarficaion, because there is always some confusion about this: Dex VI is newer than Dex III. Dex III is NOT synthetic. Dex VI was introduced in 2006 and is a synthetic blend. It runs cooler and is far better than Dex III. It's backward compatible, and in fact GM recommends using Dex VI in transmissions that previously were speced to use Dex III. That's why the OP's shopped used it in his last fluid change.

As {tpc} said, brand is not important. I've used NAPA's brand of Dex VI in several vehicles. It's about a buck cheaper per quart than the brand name stuff.

{tpc} wrote:
I have an 07 but I used mobil one in the front diff, and lucas oil in the rear, because I couldn't find the right weight stuff for the rear in mobil one.

Interestingly enough, Mobil One's gear oil does not meet GM specs. I used it anyway on the front differential of my old Trailblazer.

Matt, the spec for what type of differential fluid should be used is listed in your manual. I hesitate to tell you what my manual says because you have the previous generation of truck.

'

I will check in my manual when I get home. This is the first time I have ever changed my own Dif fluid so I am just a little hesitant.

[_tpc_]

Campfire Time wrote:

{tpc} wrote:
I have an 07 but I used mobil one in the front diff, and lucas oil in the rear, because I couldn't find the right weight stuff for the rear in mobil one.

Interestingly enough, Mobil One's gear oil does not meet GM specs. I used it anyway on the front differential of my old Trailblazer.

Matt, the spec for what type of differential fluid should be used is listed in your manual. I hesitate to tell you what my manual says because you have the previous generation of truck.

I stand corrected. 🙂 FWIW, it made me go back to double check what I used in the front, and I misspoke, it was valvoline not mobile one. I know this because I got it from advance auto in my area, and they only carry 80w90 in valvoline and 75w90 in mobile one. My manual calls for 80w90 for the front.

Now whether or not valvoline is gm spec'd I do not know, probably isn't lol. 🙂 Haven't had any issues though. 🙂

[Campfire_Time]

Just for clarficaion, because there is always some confusion about this: Dex VI is newer than Dex III. Dex III is NOT synthetic. Dex VI was introduced in 2006 and is a synthetic blend. It runs cooler and is far better than Dex III. It's backward compatible, and in fact GM recommends using Dex VI in transmissions that previously were speced to use Dex III. That's why the OP's shopped used it in his last fluid change.

As {tpc} said, brand is not important. I've used NAPA's brand of Dex VI in several vehicles. It's about a buck cheaper per quart than the brand name stuff.

{tpc} wrote:
I have an 07 but I used mobil one in the front diff, and lucas oil in the rear, because I couldn't find the right weight stuff for the rear in mobil one.

Interestingly enough, Mobil One's gear oil does not meet GM specs. I used it anyway on the front differential of my old Trailblazer.

Matt, the spec for what type of differential fluid should be used is listed in your manual. I hesitate to tell you what my manual says because you have the previous generation of truck.

[_tpc_]

As for the diff's, whatever weight is recommended and then get some good synthetic type stuff. I have an 07 but I used mobil one in the front diff, and lucas oil in the rear, because I couldn't find the right weight stuff for the rear in mobil one.

[_tpc_]

I believe as long as it says Dex VI it is the same stuff, more or less. There are a couple brands that or original source and then some are reformulaters, but in the end I don't think it matters.

I try to stick to name brand stuff. Best deal I found was on amazon, like 12 qts for $55 shipped. Havoline, which I think is a original source supplier.

[Majja13]

Old-Biscuit wrote:
If it meets MFG. Specs.......brand doesn't matter

Have you checked out what is specified in owners manual?

It calls for DEX III. Not brand specific. When I had the flush and filter done last time the shop moved up to Dex VI then new synthetic Dex III.