M931A2 wont shift to low range.

[racing4funn]

When I got the truck the shifter was disconnected so that might be a sign of what someone else knew. I reconnected it but it wont budge. My only guess is the button on the end of the shifter isnt working? Anyone been down this road and could give me advice?

 

[doghead]

Are you following the directions in the TM ?

 

[swbradley1]

Are you pushing on the brake pedal when trying? The one sitting here won't shift unless pushing on the brakes.

 

[Tow4]

Try shifting the transfer case while moving. Put the transmission in neutral first. If you can't shift it to neutral while it's rolling, you have a problem.

I can shift the transfer case in the M929 while moving, but the transmission has to be in neutral. I've had to put the transmission in gear momentarily to spin it up to shift the transfer case if I wasn't quick enough shifting the transfer case after putting the transmission in neutral while moving.

Good Luck.

The TM has all the details.

 

[racing4funn]

I have tried the slow roll in neutral. Ive tried stopped in gear and out.. I think Ive tried while on the brakes but might have to test that one again.

What does the button on the end of the handle do? A lock out?

 

[Suprman]

The button on the handle triggers a solenoid. There are 2 wires running along under the handle from the button. If you turn the truck power on without the engine running you can hear it click when you press it.

 

[m16ty]

Try shifting when the truck isn't running and has zero air pressure. If it will shift then, you're having problems with your interlock (which I suspect is the case).

In my opinion you'd be better off to just do away with the interlock. Look toward the front top of the t-case and you'll see what looks like a air cylinder end sticking out of the t-case that has a line running to the end of it. Take the line off and plug it. It should then shift much better.

 

[racing4funn]

The button on the handle triggers a solenoid. There are 2 wires running along under the handle from the button. If you turn the truck power on without the engine running you can hear it click when you press it.

Try shifting when the truck isn't running and has zero air pressure. If it will shift then, you're having problems with your interlock (which I suspect is the case).

In my opinion you'd be better off to just do away with the interlock. Look toward the front top of the t-case and you'll see what looks like a air cylinder end sticking out of the t-case that has a line running to the end of it. Take the line off and plug it. It should then shift much better.

Both interesting. I will look into these and get back

 

[M35A2-AZ]

Try shifting when the truck isn't running and has zero air pressure. If it will shift then, you're having problems with your interlock (which I suspect is the case).

In my opinion you'd be better off to just do away with the interlock. Look toward the front top of the t-case and you'll see what looks like a air cylinder end sticking out of the t-case that has a line running to the end of it. Take the line off and plug it. It should then shift much better.

That would be a good thing to try!!!!

 

[doghead]

From the -23-1TM,

TRANSFER CASE

35. HARD SHIFTING OF TRANSFER CASE

Step 1. Check transfer case fluid level (LO 9-2320-272-12).

Fill or drain to proper level as necessary (LO 9-2320-272-12).

Step 2. Inspect transfer case shift linkage for proper lubrication.

Lubricate linkage as necessary (LO 9-2320-272-12).

Step 3. Inspect shift linkage for bends, breaks, and missing parts.

If shift linkage is bent, broken, or has missing parts, notify DS maintenance.

Step 4. Check wire 586 for good ground.

Repair or replace wire (para. 3-131).

END OF TESTING!

 

[Coffey1]

Thanks dog head you have transformed into a walking talking tech book .

 

[randygk]

When picking up our M923A1 at GL I tried to put it in low range and it would not go in. As I tried to move the lever I noticed sparking near the base of the lever. The wires were chaffed bare where it goes through the floor. Looks like it might be a common issue.

 

[racing4funn]

From the -23-1TM,

TRANSFER CASE

35. HARD SHIFTING OF TRANSFER CASE

Step 1. Check transfer case fluid level (LO 9-2320-272-12).

Fill or drain to proper level as necessary (LO 9-2320-272-12).

Step 2. Inspect transfer case shift linkage for proper lubrication.

Lubricate linkage as necessary (LO 9-2320-272-12).

Step 3. Inspect shift linkage for bends, breaks, and missing parts.

If shift linkage is bent, broken, or has missing parts, notify DS maintenance.

Step 4. Check wire 586 for good ground.

Repair or replace wire (para. 3-131).

END OF TESTING!

Yea Im well past that trivia trouble shooting or I wouldnt have posted.. But thanks for your thoughts. some people will over look the obvious. Ive been setting on and playing with this problem for months.
Wire is good and tests good but I wasnt sure what it did or if needed and as others pointed out the design might be more trouble than good..

 

[M35A2-AZ]

If you push on the button in the cab can you hear a chick for the transfer case?

 

[m16ty]

In my opinion you'd be better off to just do away with the interlock. Look toward the front top of the t-case and you'll see what looks like a air cylinder end sticking out of the t-case that has a line running to the end of it. Take the line off and plug it. It should then shift much better.

I do this on every M939 truck I get my hands on. The interlock can be problematic due to faulty button, faulty wires, air solenoid not working, or sticking air cylinder. There's really no reason for it to be on there so I disable it.

 

[wsucougarx]

I had issues with shifting my transfer case when I first got it. Turns out the wire leads from the shifter button were crossed and another wire under the cab was hooked up incorrectly. That switch operates an air dump valve so you can shift the transfer case. If it's hooked up incorrectly, the air won't dump, and will not allow you to shift with the air pressure up. Are you able to shift when the truck's air pressure is depleted?
One way to find out if the button is working is to build up air pressure, shut the truck off, turn just the battery switch on, and depress the button. If you hear an audible click from the back of the truck (usu accompanied by an air swoosh) then your switch is working correctly. If not, troubleshoot via TM's.

 

[ladoublet]

I removed the line and plugged it. Still not engaging.