Tandem axle traction question

How many wheels pull under normal driving conditions????

When you lock in the axle interlock what is this doing????

My answer is 1 tire under normal conditions and the interlock locks the two rear ends together so you now have 1 tire on each axle pulling.

Another guy at work swears that 1 tire from each axle pulls all the time under normal conditions and the interlock makes the rear end positive traction locking the wheels on either side of the truck together.

I may have to eat crow tomarrow at work but I can take it. Who is correct????

Rod

I did not even know they made a setup that locked all 4 wheels together.

Rod

I've always wondered what a power divider is or does, is it the same thing?

I understand how those rears work like in your question, but I remember the time I blew a power divider to pieces in a triaxle freightliner, 8 spd low hole - deep reduction, and I was using lo range, owner had sent me to work on site, excavator operator totally overloaded me and i did not know it, should have stood on the cab protector while he loaded, this was a road truck, would handle site work, but you can't heap the 28 yard box with heavy gravel and run in soft conditions, ground was stable but spongy enough to strain the driveline, just too much weight, it let loose like a grenade, pieces of gears punched right through the cast housing, I have one piece of each in a jar, that would have really hurt someone standing near it, always wondered what that power divider actually did. I had to help repair the darned thing, but we just put a new one in, always wondered what would have caused a failure like that, better to use a heavy ole AutoCar, or Mack on site, they always took the abuse.

Funny you mention what that other switch actually does, on that freightliner, it had the big floatation tires on the front, and I had to keep those slack adjusters backed off enough to not skid, especially when slippery, that was a real hazard, and at that time it was illegal too. Then you had to be D.O.T certified to adjust your brakes, so if they got you at the checkpoint, you had to call someone in, could not do it yourself, that was a joke, if you think about it. Every morning, before heading out, I would raise up the dump body and adjust all the rear brakes, tighten em down and turn em back 1/2-3/4 of a turn, that truck always stopped well with a full load, pusher or 3rd axle had brakes too if I recall, been awhile, never knew that trucks had a switch for those fronts, if the feds outlawed it, what was the solution to the problem? Those big flotation fronts skidding was no joke, I'd rather take the ticket, boss agreed, I can remember getting material tickets at the asphalt plant for 29 ton, lot of weight, the truck had good brakes and you did not miss those fronts being backed enough to keep em skidding.

I had a front brake cam over on a R model mack once, the flatspot ruined a brand new tire, I had to run like that for a day too.