AWD Question (Business Class M2)

Your interaxle lock can be used to send equal power to the front and rear drive axles, so that in a spinning situation you will have one wheel on both axles turning. AWD switch engages the transfer case that engages your steer axle.

Interaxle lock can be left engages as normal differential action will still occur across the axles. If you had a differential lock you wouldn't want to leave that engages as you need differential action to make turns, ect.. AWD shouldn't be left engages as there is a gear reduction that takes place and that steer axle and drive axles do not operate at the same speeds, which on hard paved surfaces can be an issue.

Last 6 of the VIN on one of your trucks and I can take a better look at it's actual setup.

 

The interaxle lock switch, AWD switch and transfer case range switch apply to your vehicle. It seems that none are suggested to stay engaged at all times, only when needed.

 

You can select the inter axle lock and transfer case lock independently from each other. Having just the transfer case lock on these trucks makes me wonder if they aren't already sending power to 4 wheels at all times with an unlocked transfer case. Knowing drivers though, I would inform them if they get stuck, wait for all wheels to stop spinning, lock the transfer case, lock the inter axle, then pull to better traction and unlock.

 

All the good information aside; your picture highlights one of my pet peeves with trucks... and Internationals in particular (in my experience). Why can they not group switches for similar or related functions together? Put all the axle function switches together. Instead, they just randomly distribute them. And they often are not the same from truck-to-truck.

Case-in-point: we operated eight different Prostars over about three years. All of them were equipped with inter-axle locks, differential locks (four-way lockers) and traction control cancellation. The traction control cancellation is important when in mud or deep snow conditions... as we were often. Instead of grouping the switches together so they were easily used when needed, they were randomly distributed and not even the same from truck-to-truck. Ugh!

 

I believe the m2's have enough wiring back there to move the switches to the holes you want them to be in. Prostars I am not sure I wasn't inside the dash of many of those trucks, usually only for a SART module.

 

The M2 we work on that is 4x4 is a manual transmission and all the switches are together. We just had to replace the transfer case in it this week. They use this truck to spread lime in fields and the oil cooler for the transfer case started leaking and they had no idea. The transfer case does not hold very much oil and it burnt it up. Locked up on him while driving down the highway at 45 MPH. Left marks for a ways.