Manually shift the transfer case

[smitty5150]

Ok, my AWD is acting up. It started binding a couple months ago. I got it to disengage and pulled the plug on the encoder motor. Ran fine since then but I did need a new hub. Just replaced that and the sensor. Hooked up the motor to test and it engaged after a few turns...can't get it out of awd mode now. Mostly certain the motor is shot. Going to take a few weeks until I can pinpoint the problem and buy the parts. In the meantime, how can I force the t case back into 2nd mode? Can I just rotate the shift shift with vise grips? If so how do I know I'm turning the right way with markings on the case?

 

[Mooseman]

Don't you just love this automatic AWD junk? I'm just used to the 4x4 system my TB has and to just wait for the AWD to engage when a wheel slips and then bang, it engages. Seriously thinking of swapping it with a 4x4 transfer case and disconnect and wiring it up myself.

I think I do remember someone mentioning that you can shift it like you said but won't that leave an open hole where the shaft is? If the TC is in 2wd but he encoder is stuck in AWD, you won't be able to put it back.

Roadie is the authority on this system and should be able to answer your questions.

 

[smitty5150]

The case will will be sealed but shaft exposed. I don't think that's too harmful. I'd rather do that than pull the driveshaft.

 

[smitty5150]

Encoder def the issue. Took it off and all is well. I wish I could say what I did to get it back in 2wd. It would seem like the awd t case sits in 2wd always and the encoder just pins it in awd when engaged.

 

[IllogicTC]

I was under the assumption that the AWD system forced the 4x4 to be enabled at all times, of course with as little as 5% torque heading up-front, which would seem a bit like it's in 2HI.

 

[Mooseman]

Nope unless mine operates differently. Transfer case engages front shaft only if there is rear wheel slippage. I hate it. Only way I can see how to cheat the system would be to slip the wheels and then when it engages, turn off the power to the encoder motor or TCCM. Maybe a switch the the fuse would work.

 

[Sparky]

But if you leave it transferring full (or even half) power to front wheels you'll get crow hopping since our cases aren't differential style.

 

[Mooseman]

I used to put my TB in 4hi in snow without any problems.

 

[Sparky]

Well right in snow you're fine but get on some non slick surfaces and ehhh

 

[smitty5150]

Even if there's 5% power normally that must be where I am. I was getting binding and crow hop even on slight turns. Couldn't get the motor to reset but pulling it stopped the issue. I haven't read into the way the system works but I would assume the awd and selectable cases work differently.

 

[HARDTRAILZ]

They do function differently.

 

[chipjumper]

Email the boys at 4x4 Posi-Lok and see if they have a solution. They offer a neat solution to the same issue with other GM SUV's and trucks.


e-mail for sales related issues (USA & Canada): sales@4x4posi-lok.com
e-mail for technical issues: tech@4x4posi-lok.com
Email outside of North America: international@sporttruckusainc.com
Phone: 517-279-7177
Fax: 517-278-2316

 

[Mooseman]

Just looking at their site, it's a replacement for the old vacuum actuated disconnects, which went away with the S series trucks. I remember how much they failed. It's basically just a cable they offer to replace it.

 

[chipjumper]

Yeah but they also make manual kits for the K series that have electric setups. Is our front diff unique for our vehicle? Do they only use it with the TB/Envoy or also the Colorado/Canyon?

 

[coolasice]

Yeah but they also make manual kits for the K series that have electric setups. Is our front diff unique for our vehicle? Do they only use it with the TB/Envoy or also the Colorado/Canyon?

360 only.

 

[Mooseman]

As well as the disconnect.

 

[swede]

Isn't it a couple of TSB written about the TC problems. I been reading all the TSB on GMTNATION and know there was a couple.