4WD causes Stabilitrack to engage

[kjkim93]

Got stuck. Guys I need help. I have no codes. My 4x4 switch works and all the right sounds are made and felt. But when in 4x4 as soon as I touch the accelerator stablitrack kicks in and I can't move. What's the problem? Auto allows movement in front and rear. But 4H engages and fronts dont move.

 

[DocBrown]

Have you changed the Xfer case fluid every 50k as the manual calls for?

 

[kjkim93]

Have you changed the Xfer case fluid every 50k as the manual calls for?

Yes. Changed it at every given interval. Went to the mechanic. 4x4 is engaged. From tires move with rest in reverse and drive. Handspun the fronts and they moved also.

 

[kjkim93]

Update. Using 4x4 the car will not engage the front in snow at all. Got stuck on a hill. 4x4 didn't help one bit. Why did it work when it was up on a lift? Mods feel free to move this to the Trailblazer section.

 

[Mooseman]

The front disconnect could be defective, the encoder motor or the transfer case could also be borked. The usual is the disconnect.

 

[kjkim93]

The front disconnect could be defective, the encoder motor or the transfer case could also be borked. The usual is the disconnect.

I can hear all the sounds except the one on the passenger side. That's the disconnect right?

 

[Mooseman]

That's right.

 

[kjkim93]

That's right.

While up in the air the system works. But when I'm in snow no power to front wheels. If I replace it should I try the ones I see on eBay? Where they were rebuilt "better"? Any recommendations?

 

[Mooseman]

If you mean this one on eBay:
http://www.ebay.com/itm/161509948512?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

I haven't heard anything negative about them and they're new. Best price I've seen for them.

Did you check to see if it was just the actuator motor on the disconnect first? I'd confirm that the disconnect is the cause first.

 

[kjkim93]

If you mean this one on eBay:
http://www.ebay.com/itm/161509948512?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

I haven't heard anything negative about them and they're new. Best price I've seen for them.

Did you check to see if it was just the actuator motor on the disconnect first? I'd confirm that the disconnect is the cause first.

While I've seen how to test everything else how can I test if it's just the motor?

 

[Sparky]

Yeah I'd start testing it. Check for function of the actuator, and check for play/slop where the axle goes in.

How many miles are on the vehicle? Not uncommon for the disconnect to start showing wear after 100k miles. Mine got to 135k before it showed much wear but it still worked.

 

[kjkim93]

Yeah I'd start testing it. Check for function of the actuator, and check for play/slop where the axle goes in.

How many miles are on the vehicle? Not uncommon for the disconnect to start showing wear after 100k miles. Mine got to 135k before it showed much wear but it still worked.

I have around 115,800 miles. The reason it must have finally broken or something was the fact i got stuck in an ice and snow field. How can I test the actuator itself?

 

[Sparky]

If you pull the actuator from the side of the disconnect (2 small bolts) you can pull it out and then engage the 4x4. It should move in and out depending on which mode you're calling for. If it moves then you know it isn't the actuator.

You could test the front disconnect by engaging 4x4, jack the passenger side up (in park of course, truck turned off), leaving the driver side tire on the ground, and then trying to spin the front wheel by hand. If 4x4 is engaged properly you shouldn't be able to spin it. If you can, look underneath the truck while spinning the front wheel. If the front drive shaft spins then you've got some issue at the transfer case (not engaging due to encoder motor problem perhaps, or something else). If the drive shaft does not spin, then the disconnect or the differential is broken. It would be far more likely the disconnect is the problem than the front differential.

 

[kjkim93]

If you pull the actuator from the side of the disconnect (2 small bolts) you can pull it out and then engage the 4x4. It should move in and out depending on which mode you're calling for. If it moves then you know it isn't the actuator.

You could test the front disconnect by engaging 4x4, jack the passenger side up (in park of course, truck turned off), leaving the driver side tire on the ground, and then trying to spin the front wheel by hand. If 4x4 is engaged properly you shouldn't be able to spin it. If you can, look underneath the truck while spinning the front wheel. If the front drive shaft spins then you've got some issue at the transfer case (not engaging due to encoder motor problem perhaps, or something else). If the drive shaft does not spin, then the disconnect or the differential is broken. It would be far more likely the disconnect is the problem than the front differential.

Thank you. The one thing I remember from trying to go up a hill was a clattering sound from the right passenger side? Im guessing it might be the bearings inside the disconnect?

 

[Sparky]

Yeah, could be that or the shift fork broke and the piece or the collar is rattling against the gears.

 

[kjkim93]

Yeah, could be that or the shift fork broke and the piece or the collar is rattling against the gears.

So a replacement of the disconnect would be nesscary i assume. Thank you so much for all the information.

 

[Sparky]

Or a rebuild. I rebuilt mine when it was worn. Costs less than replacing, but it is more work. If yours is broken and you opt to rebuild let me know what is broken inside and I may have the part you need. I think I still have a spare shift fork around here for example. Some of the other things (bearings, seals, washers) that would need replaced are dealer only last I checked.

 

[kjkim93]

Or a rebuild. I rebuilt mine when it was worn. Costs less than replacing, but it is more work. If yours is broken and you opt to rebuild let me know what is broken inside and I may have the part you need. I think I still have a spare shift fork around here for example. Some of the other things (bearings, seals, washers) that would need replaced are dealer only last I checked.

If i do replace it I plan to keep the old one, and fix it up as a precaution for the future. When I do this I will let you know what is broken. Thank you so much for the help.

 

[kjkim93]

Thread back from the dead. So I bought a new front disconnect, haven't changed it yet. When i do test the 4x4 out I do not hear the actuator sound from the front. But when the car is on the lift and i move a tire, all four tires engage under throttle. What could be the issue?

 

[Sparky]

Off the ground you don't have much resistance on anything so it could function "ok" there. Just swap the disconnect since you have it and go from there.

 

[kjkim93]

Ended up replacing the front disconnect. Everything works well again. Havent taken the old one apart but if i shake it, it rattles. LOL Now to wait for winter.