Slow to come out of 4x4

[jdr1965]

Well I borrowed my friends garage and lift over the weekend, drained and refilled the t-case, decided to go with Valvoline Dextron VI synthetic. Local GM dealer parts mgr consulted their techs, and they all agreed since it had Dex III originally, that VI would be even better.

Friend had a Snap On "Modis" , he checked for codes and had a evap code in history. He tried to check for trans or t-case code, but unit kept saying it could not communicate, and my friend stated he wasnt sure why, but that it may need to go on a Tech 2 scanner.

Test drive reveals no change, I went ahead and serviced all the gearboxes while I was at it, put Castrol Syntec synthetic 75W90 in both differentials, greased all grease fittings, changed the oil with Valvoline 5W30, and a wix filter. Also used his air brake bleeder, and flushed out the brake fluid, and put in DOT 3 synthetic. The transmission and radiiator was flushed last summer so it was OK

I think I may drive it a while, its really not a big deal, truck seldom gets in 4x4 anyways, I almost wonder if its a normal operation, because I am testing it, in an asphalt parking lot, should it "immediately" disengage from 4x4 when you push the 2H switch while driving at a very slow speed, or because of the drag from the asphalt is causing it to delay in dis-engaging? I may need to go "test drive" similar truck with same setup to see if it does the same thing.....

Thanks again for all the suggestions!

[MT-2500]

Originally Posted by jdr1965

Well I borrowed my friends garage and lift over the weekend, drained and refilled the t-case, decided to go with Valvoline Dextron VI synthetic. Local GM dealer parts mgr consulted their techs, and they all agreed since it had Dex III originally, that VI would be even better.

Friend had a Snap On "Modis" , he checked for codes and had a evap code in history. He tried to check for trans or t-case code, but unit kept saying it could not communicate, and my friend stated he wasnt sure why, but that it may need to go on a Tech 2 scanner.

Test drive reveals no change, I went ahead and serviced all the gearboxes while I was at it, put Castrol Syntec synthetic 75W90 in both differentials, greased all grease fittings, changed the oil with Valvoline 5W30, and a wix filter. Also used his air brake bleeder, and flushed out the brake fluid, and put in DOT 3 synthetic. The transmission and radiiator was flushed last summer so it was OK

I think I may drive it a while, its really not a big deal, truck seldom gets in 4x4 anyways, I almost wonder if its a normal operation, because I am testing it, in an asphalt parking lot, should it "immediately" disengage from 4x4 when you push the 2H switch while driving at a very slow speed, or because of the drag from the asphalt is causing it to delay in dis-engaging? I may need to go "test drive" similar truck with same setup to see if it does the same thing.....

Thanks again for all the suggestions!

As stated in upper post going forward on dry payment or mismatched tires or rear ends can cause a transfer case to bind up and not shift out of 4W very good.


Your dealership is not very hip on what fluid should be used.

They should check there repair manuals and TSB's on that.
There giving you the wrong advise on fluids can cause a lot of damage to your truck.

Dex 6 is good for moswt of the automatic transmissions but not good for some standard gear transmissions and some transfer case.

If a scanner will not communcate you have a electrical problem.
The snap on Scanner manual tells you what to check for with that problem and or a good repair manual has a repair flow chart for that problem.

If it will not shift out of 4W going forward on dry payment/black top.
Do like like some trucks and bus do.
Stop look and listen like at a railroad crossing and put transmission in neutral or back up a little and roll forward.

[jdr1965]

Well you got me worried now about the fluid I put in the t-case. As a result, I will drain out the Dex 6, and put in the auto track blue fluid, # 12378508.

Please advise that this is the CORRECT fluid to use. My vin# is 1GCEK19R8XR116687



Any problem with the gear oils I put in the differentials, and the synthetic DOT3 brake fluid I replaced?

[MT-2500]

Originally Posted by jdr1965

Well you got me worried now about the fluid I put in the t-case. As a result, I will drain out the Dex 6, and put in the auto track blue fluid, # 12378508.

Please advise that this is the CORRECT fluid to use. My vin# is 1GCEK19R8XR116687



Any problem with the gear oils I put in the differentials, and the synthetic DOT3 brake fluid I replaced?

If it is the auto matic 4W transfer case with the auto button on shift buttons only use the GM blue auto trac fluid.

Have you dealer run your vin for correct and updated type fluids.
Also have the run and check the TSB's on fluids.
From what they told you they need to get updated on them to.

And read what Jcat has stated several times.

[jdr1965]

Truck does not have auto track transfer case. Original fluid was red, atf. Owners manual said to use Dex III.

After searching other truck and gm forums, I am not alone in the confusion over what fluid is to be used in this model. I see that others have been told by their dealerships different things. My dealership ran the vin, asked some of their "techs", and even called the "gm hotline" for guidance. Thats when they said Dex III or Dex VI. They said it only needed the blue autotrack fluid IF it had the automatic 4x4 t case (which it doesnt). Keep in mind small town, small dealer, but good people, reputation, and good work reports over the years...

Since my local dealer wasnt much help, and next dealer is quite a drive away, was hoping some of you guys that had alot more knowledge and experience than me had the ability to run my vin # and advise me of what fluid to buy, or leave what I put in it ....

[jdr1965]

Found this bulletin:



Subject:Manual Transmission Fluid Usage In 2007 And Prior Manual Transmissions And Transfer Cases - keywords case fluid manual transmission transfer #PIP3836B - (02/05/2007)


Models:2007 and Prior Passenger Cars and Trucks
2007 and Prior HUMMER H2
2007 HUMMER H3
2007 and Prior Saturn Passenger Cars and Trucks


This PI is superseded to add a note under concerns. Please discard PIP3836A.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:

Use of manual transmission fluid part number 88861800 U.S. (88861801 Canada) in place of Dexron III.

Important Note: If the vehicle owners manual lists Dexron VI as the recommended transmission, transaxle or transfer case fluid disregard any information supplied in this PI. Use eSI and or the vehicle owners manual to determine what type of fluid should be used prior to referencing the below information

Recommendation/Instructions:

Manual Transmission fluid part number 88861800 U.S. (88861801 Canada) is currently available through GMSPO. Current and past model vehicles listed above with either a manual transmission or transfer case that REQUIRE Dexron III should use the above listed saturn parts manual transmission fluid. This fluid is a direct replacement for Dexron III in manual transmissions and transfer cases. DO NOT use Dexron VI in place of the manual transmission fluid in any manual transmissions or transfer cases as a failure may result.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.


Going with the gm fluid 88861800!

[jdr1965]

Drained the Dex 6 out, put in the gm 88861800 fluid, drove it for several days, worked the 4x4 buttons often while on dirt roads, bought plenty of gm fluid, so re-drained and installed fresh 88861800 again.

Problem still exists, no changes.

4x4 actuator?

[MT-2500]

Originally Posted by jdr1965

Drained the Dex 6 out, put in the gm 88861800 fluid, drove it for several days, worked the 4x4 buttons often while on dirt roads, bought plenty of gm fluid, so re-drained and installed fresh 88861800 again.

Problem still exists, no changes.

4x4 actuator?

Have you tryed the old back up and put in neutral to see if it helps on going from 4W to 2-W?
If the snapon scanner will not communicate find out why.
That could be some of your problem.
You need to get it on a good transmission/transfer capable scanner that will communicate with them and get codes and do the shift test built into scanner.

What 4W selection are you having trouble going to 2W?
4W auto or 4W high or 4W low?

[jdr1965]

Yes ,I tried the old backing up or putting in nuetral, made no difference.

This truck does NOT have auto 4x4! The switches are 2H, 4H, and 4L. I am using 4H, and switching it back to 2H, you hear the actuator "clicking" but your still in four wheel drive, unless you get up to highway speeds. The issue happens not only in a parking lot, but I tested it off road, and on dirt roads, and doesnt seem to make a difference.

Will try to get truck scanned again, maybe we can a better reading. It was rushed and at the end of all my maintannce I was doing to the truck, and my friend was ready for me to finish up and get out of his shop!

I will keep you posted!

[MT-2500]

Originally Posted by jdr1965

Yes ,I tried the old backing up or putting in nuetral, made no difference.

This truck does NOT have auto 4x4! The switches are 2H, 4H, and 4L. I am using 4H, and switching it back to 2H, you hear the actuator "clicking" but your still in four wheel drive, unless you get up to highway speeds. The issue happens not only in a parking lot, but I tested it off road, and on dirt roads, and doesnt seem to make a difference.

Will try to get truck scanned again, maybe we can a better reading. It was rushed and at the end of all my maintannce I was doing to the truck, and my friend was ready for me to finish up and get out of his shop!

I will keep you posted!

On hearing actuator clicking are you refering to the actuator on front axel or encorder motor on transfer case or the relay or computer?

On testing the transpher case shifting
First step is to watch the shift button lights when key is turned on.
Do they all blink on time and then the light for what position it is in stay on?

Also on transfer case checking for codes with the 243C a scanner is not used.
To check for codes on them ground pin 13 on diagnostic connector and turn key on and read out how many blinks you have on shift button lights.

Codes read out is only 1 or 2 or 3 or 4.
If any codes.
Clear codes and see what returns.
Post back what code or codes you have before and after clear codes.

[j cAT]

Originally Posted by jdr1965

Yes ,I tried the old backing up or putting in nuetral, made no difference.

This truck does NOT have auto 4x4! The switches are 2H, 4H, and 4L. I am using 4H, and switching it back to 2H, you hear the actuator "clicking" but your still in four wheel drive, unless you get up to highway speeds. The issue happens not only in a parking lot, but I tested it off road, and on dirt roads, and doesnt seem to make a difference.

Will try to get truck scanned again, maybe we can a better reading. It was rushed and at the end of all my maintannce I was doing to the truck, and my friend was ready for me to finish up and get out of his shop!

I will keep you posted!

your first posting states slow to come out of 4wd . So does the drivetrain come out of 4WD and get to 2WD ?

If the drivetrain does shift to the different selections , but with some delay difficulty this may mean the transfercase has problems since the electrical is working and the mechanical is restricting the speed of selection..

you may indeed have no codes if the electrical is working..no codes for a damaged transfercase...

[jdr1965]

jcat- yes it does go from 4H to 2H, but it takes getting some speed, no flashing lights ever on buttons, I hear the click of something engaging or un-engaging, but you can tell by the steering your still locked in, but if you keep driving it does eventually go back to 2 wheel drive. Kinda funny, I have had 4 of these trucks, all same year styles, 97-99 z71's, but never noticed this on the others, they all had 150K or more miles, the one I have now only has 57K, and is in mint condition. I didnt buy it new, the previous owner I guess could have driven it in 4H on the pavement for ever and ever, you never know. But the original fluid in the transfer case was clean as new, and had no burnt smell, and no debris came out ( i looked)....

[j cAT]

Originally Posted by jdr1965

jcat- yes it does go from 4H to 2H, but it takes getting some speed, no flashing lights ever on buttons, I hear the click of something engaging or un-engaging, but you can tell by the steering your still locked in, but if you keep driving it does eventually go back to 2 wheel drive. Kinda funny, I have had 4 of these trucks, all same year styles, 97-99 z71's, but never noticed this on the others, they all had 150K or more miles, the one I have now only has 57K, and is in mint condition. I didnt buy it new, the previous owner I guess could have driven it in 4H on the pavement for ever and ever, you never know. But the original fluid in the transfer case was clean as new, and had no burnt smell, and no debris came out ( i looked)....

so this means you will most likely get no codes..since it does work ...just takes longer.. with the fluid changes and no change in operation it may be the switches or other electrical components/controls.

when the service 4wd lt comes on , get codes and post back ...might take a few years...

[777stickman]

I've said it twice, but I'll say it one last time. You need to look at the front axle. The front actuator, the wiring to it, something mechanical in the front axle. You've already put in a lot of time, effort & $$ without success. I hope you'll seriously consider this.

I may be wrong, but if I had the issues as you have described them, that's the 1st place I would go to.

Good luck to you.