transfercase is stuck in 2wd mode.

[ColtRice17]

I just purchased an 86 M923A1 and can't get the transfercase to shift. I push the button wait a while and pull the lever but it wont budge. I checked the linkage and its free but something is holding it.

 

[98G]

Try to shift it with the air system empty and the truck not running. If that works, just disconnect the air to it.

98G

 

[dmetalmiki]

I'm sure someone with knowledge of your truck will hopefully step in, Mean time, Well it's 4 wheel drive actually, you need the two fronts to operate being then it will be 6 wheel drive, Have you read and or checked the T.M.s applicable to your tuck from this site?

 

[73m819]

I'm sure someone with knowledge of your truck will hopefully step in, Mean time, Well it's 4 wheel drive actually, you need the two fronts to operate being then it will be 6 wheel drive, Have you read and or checked the T.M.s applicable to your tuck from this site?

The above is ONLY true if the truck is a Marine truck, other rise being the truck has OPEN diffs, only one side will pull per axle, so the op statement could be true "TWO wheel drive"

 

[ColtRice17]

Yes I am reading all applicable TM's and it will not shift with or without air running or not. Could it be the silonoid because when I push the button nothing happens. And I'm not sure if I have open diffs or not. what's the best way to find out? Axle codes or something?

 

[fuzzytoaster]

Follow what 98G said. Also if there is no power going to the switch it will not let you shift, make sure your batteries are good.

 

[98G]

Follow what 98G said. Also if there is no power going to the switch it will not let you shift, make sure your batteries are good.

I've shifted dead trucks with no batteries. As long as there's no air pressure it should shift.

 

[ColtRice17]

Batteries are brand new but ill check the air and let you know

 

[Csm Davis]

98G is correct but you have to understand when he says no air that means shut the truck off then open the gladhand on the driver front and let it bleed off all the air and you might even need to pump the brake petal to get all of it out.

 

[ColtRice17]

Ok ill check in the morning. I figured if I pump the brakes and the horn doesn't work I don't have any air right?

 

[ColtRice17]

Csm Davis are you still parting out that 939? If so where is it located and can I have the cab and doors and how much?

 

[Csm Davis]

Csm Davis are you still parting out that 939? If so where is it located and can I have the cab and doors and how much?

Yeah bud I have several cabs, Hattiesburg, MS 500

 

[ColtRice17]

Hmm I may have to plan a ride down there.

 

[porkysplace]

Ok ill check in the morning. I figured if I pump the brakes and the horn doesn't work I don't have any air right?

So did you get the transfercase to shift ?

 

[ColtRice17]

No. I've cleaned the linkage and transfercase cause it had lots of mud on it. I've checked airlines and pressure etc. All that's left is to take a multimeter to the electrical part of it.

 

[Floridianson]

No. I've cleaned the linkage and transfercase cause it had lots of mud on it. I've checked airlines and pressure etc. All that's left is to take a multimeter to the electrical part of it.

Yea it does like to have a slight roll of the tires to help with the shift but that can't happen if we try the no air trick.
I never did the block off the air trick and when all is working correct I feel it is better to have the transfer case locked in range.
As said try and block off the air going to interlock cylinder might be the way to go and transmission is in neutral.

 

[ColtRice17]

I soaked everything down in penetrating oil and it still wont budge even while moving in a little sand. I've pulled the solenoid off for cleaning and inspection since I can't seem to get it to move. Is it save to power the solenoid with straight 24V? I just want to make sure it works to mark it off the list.

 

[ColtRice17]

Ok sorry about that my phone is sucking today. I have disconnected the air to it entirely. I love working on this truck there is actually room to work on things haha

 

[ColtRice17]

alright so after pulling and cleaning the solenoid, shift linkage and checking all the air lines etc it still wont shift. And the truck wont do over 45 I'm wondering if its stuck in low range 2wd? Is that even possible?

 

[Csm Davis]

Okay colt at this point we need to check out a few things. Do you have the shifter down, parallel to the floor, in high range? Check the switch on the shifter with a multimeter then at the solenoid. If you have power and the air is dumping when you push the button, then remove the actuator, it unscrews, and then use a magnet to pull the detent pin. At this point you should be able to shift freely from high to low and back with minimal effort.