Which Fluid For Electronic Transfer Case?

GeeJay · October 24, 2007

The techs at my stealership argued about this one.

2007 Sierra 2500HD 4x4

Manual says use AutoTrak II for automatic transfer case.

Manual says use GM Manual Trans Fluid for manual transfer case.

Operating instructions show

1. Automatic Transfer Case (push buttons)

2. Manual Transfer Case (Shift Lever)

3. Electronic Transfer Case ( different push buttons)

Mine is electronic.

One argument is that the Electronic TC is classified as an automatic.

The other is that it is manual, just with electric motors shifting instead of a shift lever.

A number of dudes on other forums have different opinions also, however there are numerous mentions that Dexron III ATF can be used in the manual TC instead of GM MTF. A GM service bulletin confirms that.

Okay - let's hear about it!

cerbomark · October 24, 2007

my book says Dextron VI. Autotrax is probably OK too.

Krambo · October 24, 2007

my book says Dextron VI. Autotrax is probably OK too.

Hey Mark! How's the V-Max holdin' up?

Back on topic,...I would use the AutoTrackII.

fourwheelinfool · October 24, 2007

Okay.

Now very carefully kneel down, lie down, and shimmy under your truck. When doing this make sure to wear an old shirt as you may get it dirty. Now look for the little marks that indicate your transfer case model and appropriate fluid. The transfer case is the funny transmission-looking thing that your driveshaft slips into, it is not the transmission! Your driveshaft is the round metal "pipe" with funny looking crosses at the joints.

This solution can be a little hard to think of at first, but that's what we're here for!

Freyguy · October 24, 2007

I've always heard that if you have an Auto 4x4 button, you need the fancy GM fluid. Anything else can be ATF. I'm running amsoil with good results. NP263

dewfpo · October 24, 2007

The TC in the 2500HD's is not AutoTrak. These were limited to the 1500's.

Our TC does not have an "Auto" position like the AutoTrack cases and does not shift AUTOMATICALLY when needed (if in AUTO mode).

We have either a manually shifted or electrically (not electronically) shifted manual case. We have to tell it when to go into 4WD (with the push of a button) or the pull of a lever.

Some folks use the term "automatic" interchangeably for the AutoTrack TC and the electrically shifted manual case and they shouldn't.

DEWFPO

GeeJay · October 28, 2007

UPDATE:

GM Service Helpline took 2 days to come back with the answer.

The "Electronic" (GM's term referring to the controls, not the electric shift motors)) TC is considered a manual TC as per Dewfpo's reply. Only the AutoTrak is automatic.

GM Bulletin 1838912:

"If fluid part number 88861800 U.S. (88861801 Canada) is unavailable when servicing a manual

transmission or transfer case, Dexron III can be used in it's place. DO NOT use Dexron VI in place of

the manual transmission fluid in any manual transmissions or transfer cases as a failure may result"

Sorry Cerbomark, but if you have Dexron VI in your TC, you better get it changed. However I think you might have misread transmisson fluid (Allison) for transfer case. As you don't have an Allison with your 6L, you shouldn't have Dexron VI in anything.

Not everybody using this forum is young enough or ablebodied to crawl around under the truck. If the techs in the stealership don't take know to take the info off the TC, the average DIYer wont know about it either, so that's a good one FourWheelin Fool. However, condecending instructions won't gain you any respect, just the impression that you don't necessarily have to be fourwheelin.

Thanks guys

GeeJay

fourwheelinfool · October 29, 2007

Well I conceed that it may be different on your truck, but mine has DEXTRON IIE or III clearly in view. A Haynes manual may also have worked.

Since you mentioned it "fourwheelin" is in reference to my four tires and "fool" is what a lot of truckers call "four wheelers." My tires aren't usually muddy if it makes you feel any better.

I do give you credit on the 8.1L!

cvandegna · November 2, 2007

I have the NP263 in mine - and just put in Amsoil 5W40 European Car Formula Synthetic motor oil per the Amsoil online application guide. Hoping it isn't a typo on the website - anybody else running this?

cerbomark · November 2, 2007

Thanks, No I didn t change mine but looked in the book. Sorry about the confusion. The book only lists one transfer case(4WD) with Dexron VI. Book is for 07 Silverado. I still can t find out what type of diff fluid my truck uses??? It says 75w-90 synthetic but i thought the rear needed something special?? Is it me or does this owners book S###?

cvandegna · November 5, 2007

Thanks, No I didn t change mine but looked in the book. Sorry about the confusion. The book only lists one transfer case(4WD) with Dexron VI. Book is for 07 Silverado. I still can t find out what type of diff fluid my truck uses??? It says 75w-90 synthetic but i thought the rear needed something special?? Is it me or does this owners book S###?

Ditto here on the diffs. And after much reading was anticipating finding "grape juice fluid" in the rear diff - and did when I dropped it. Front had what looked to be regular 75W90. I replaced both with Amsoil Severe Gear 75W90, and no issues yet. Just drove it from Ft Worth to Chicago and back this weekend to pickup a buddy's '34 Ford on my car trailer and no issues. I think it actually got rid of a bit of the driveline noise. And I also notice a quieter shift of my TCase yesterday - dunno if it's attributable to the fluids, or wishfull thinking.

cvandegna · November 9, 2007

I have the NP263 in mine - and just put in Amsoil 5W40 European Car Formula Synthetic motor oil per the Amsoil online application guide. Hoping it isn't a typo on the website - anybody else running this?

**IMPORTANT UPDATE**

Apparently Amsoil did a software implementation project 2 weeks ago, that caused some anomalies in their online application guide. As a result, improper fluid and filter specifications were displayed at least during the week of Oct 29-Nov 2. If you did any PM using Amsoil products and did a lookup around this time - double check to make sure you used the correct fluids & filters. Contact your dealer to resolve.

5W40 European Car Formula CAN NOT be used in the tcase. Just dropped mine last night (not toasted thank God) and filled with cheapo Dex III to slosh around and flush before the good stuff (Amsoil Synth ATF) goes in.

gmc_todd · December 6, 2007

I read on another site (theDP) that 5w30 motor oil is being used in transfer cases all the time. In fact, Rockland gear suggests even adding an extra QT. to help with heat and fluid loss. I thought at first it was only recommended for the diesels, but apparently it's not a bad idea for the gassers either. It applies to the 261 and 263 model TC's

I'll post a link at the bottom. It is a very long read but interesting. The document in question is 3/4 down page 3.

Transfer case Info

This could be old news too, I am new here.

Todd

anealysr · December 26, 2007

The TC in the 2500HD's is not AutoTrak. These were limited to the 1500's.

Our TC does not have an "Auto" position like the AutoTrack cases and does not shift AUTOMATICALLY when needed (if in AUTO mode).

We have either a manually shifted or electrically (not electronically) shifted manual case. We have to tell it when to go into 4WD (with the push of a button) or the pull of a lever.

Some folks use the term "automatic" interchangeably for the AutoTrack TC and the electrically shifted manual case and they shouldn't.

DEWFPO

My 2000 2500HD has Autotrack as I have the Auto button and it works great. I run it on these nasty Ga clay roads all the time and can feel when it kicks in.