M35A3 front axle will not disengage...

[Mattwarr87]

I have searched through the forums...idk maybe I didn't search hard enough but I couldn't find an answer to my problem. Anyways...when I drive in full 6x6 and then flip the lever on the bottom of the dash to disengage the front axle, it isn't disengaging. You hear the air discharge when you flip the lever, but the light stays on and it really drives like it is still locked in 6 wheel drive. After a while the light will go off and it seems to drive better. What could be causing this?? Thanks in advance!

 

[Scar59]

Has the truck sat for a long time? Sounds like the transfer case shift actuator is gummed up. It can be removed and cleaned, may need new seals.
pretty easy stuff.

 

[Floridianson]

Are you letting off the throttel or hitting netrual. Don't think it will disengage under drive line load.
That plunger /piston is spring loaded so just needs air to ingage.

 

[Mattwarr87]

That's good info about shifting to neutral. Didn't know that. And I will check the shift actuator and clean it. Thanks!!

 

[glcaines]

As Floridianson said above, it is quite common to stay engaged if the front driveline is under load. If you stop and back up it will normally drop out almost immediately.

 

[Floridianson]

As Floridianson said above, it is quite common to stay engaged if the front driveline is under load. If you stop and back up it will normally drop out almost immediately.

When I posted I was not thinking A3. Yes try and go neutral to reverse and I bet it will disengage. The air cylinder is a pain to get off so if it does in gage I would leave that alone for now.

 

[Mattwarr87]

Well, I tried shifting to neutral and disengaging, tried backing up, still disengages when it wants to. Usually takes anywhere from 15-30 minutes to disengage. Where exactly is the air cylinder located? Or which TM might I find it in? Thanks!

 

[gringeltaube]

Well, I tried shifting to neutral and disengaging, tried backing up, still disengages when it wants to. Usually takes anywhere from 15-30 minutes to disengage.

You might have a malfunctioning switch. Next time this happens, try to disconnect the line down to the T-Case. There should be no air pressure, immediately after switching off.

Where exactly is the air cylinder located? Or which TM might I find it in?

https://www.steelsoldiers.com/upload/M35/TM9-2520-246-34-1.pdf, Page 2-174

 

[Floridianson]

Well if your going to disconnect the line at the T case I might put some oil in the hose before you reinstall it.

 

[WillWagner]

Or take the outlet line off of the switch...that way you don't get too dirty

 

[Mattwarr87]

It was the dash switch...replaced it with one off of a parts truck we have and it works now. Thanks for all the help and advice!!

 

[Eliteweapons]

The good news is that the front axle ENGAGES and it was an easy fix.

It was the dash switch...replaced it with one off of a parts truck we have and it works now. Thanks for all the help and advice!!

 

[Mquirin]

I just got my first a3, and the steering and braking are extremely stiff. Would having front wheel drive engaged cause this? I've looked all over and cant find anything to tell me if "off" or "on" engage the front axle. What should I set it to for the front axle to disengage? Should it feel like I'm breaking my arms to steer this truck? Thank you.

 

[porkysplace]

I just got my first a3, and the steering and braking are extremely stiff. Would having front wheel drive engaged cause this? I've looked all over and cant find anything to tell me if "off" or "on" engage the front axle. What should I set it to for the front axle to disengage? Should it feel like I'm breaking my arms to steer this truck? Thank you.

Have you read the -10 TM ?
TM9-2320-386-10.pdf
TM9-2320-386-10 Operator manual for the M35A3.
page 43 of 238 show the switch..

Reading the operator's TM will save money in the long run from damage by improper use.

The steering is air-assist but there is a valve that gives issues .

TM's for the Deuce


Air-O-Matic Air Assist Steering Instructions Scanned Blue Prints 12132493 & 12430289
[h=1]A3 Air/Steering Issue[/h]

 

[Mquirin]

Thank you for the reply Pokysplace! Yes, I have read all TMs and OMs for this truck, including what you attached and countless forums. No where can I find if having the switch set to "in" or "out" engages or disengages the front wheel drive. Does "in" mean on or off? Does "out" mean on or off?

I did make sure the Power Assist Valve on the firewall was all the way open (unscrewed), but I didn't notice a change.

 

[porkysplace]

Thank you for the reply Pokysplace! Yes, I have read all TMs and OMs for this truck, including what you attached and countless forums. No where can I find if having the switch set to "in" or "out" engages or disengages the front wheel drive. Does "in" mean on or off? Does "out" mean on or off?

I did make sure the Power Assist Valve on the firewall was all the way open (unscrewed), but I didn't notice a change.

Out means OFF.

 

[Mquirin]

Thank you!

 

[gimpyrobb]

You can pull the spline caps off the front axle to see if its still active.

Moisture in the air system will reak havoc in your air systems. Id go through the air system first then check the air assist and brake booster. The air drier should be serviced yearly.

Also, I'd pull the regulator off the air assist. I did on mine and have had no issues for 2 years.

 

[glcaines]

Check the air pressure regulator for the pneumatic steering assist. Failure of these regulators is not uncommon. I had to replace the one on my A3 after about a year of ownership. Very easy to replace. I found an NOS regulator on Ebay for $15.00 and bought two so that I have a spare. If everything is working properly, the A3 is very easy to steer.