Difference between 2 & 3 rear Axles?????

Extra tires don't help climbing up the hill generally. We had tag axles under our trucks and generally put them up when getting ready to climb or slide hills that are too steep to walk on.

They are handy for weight purposes and rarely for power on all three axles due to steering problems that get introduced at that point. Generally your engine is too runt to really provide that power. You want something like 2500 pounds torque and 700 horse to feed three axles back there.

 

My old man did just fine with a 475 HP C-15 in his tridrive. His total GVW was always around 120,000ish lbs. His 2nd tridrive with a 530 ISX blew the doors off that Cat all day long though.

 

I never ran tri-drives, so I'm not 100% familiar with setting them up, but IIRC they have to carry a minimum of 27% of the drive axle weight on the steer in our neck-of-the-woods.

 

I was going to post that but I couldn't cite a source. I do remember reading that on the BC website though. That's why all these newer tridrives are coming with 18-20k lb steer axles. It has to do with ensuring there's enough traction on the steer tires so you can safely turn.

 

You see tri-drives mostly up in Canada where the weight laws allow some advantage for a complete set of duel tires on a tripple axle drive set up.

Down here in the states it is hard to make a tri-drive setup justify the cost, hassle, or weight because you can almost always pull the same weight, even on an extended permit, with a tandem and a drop axle. Hence, try-drives don't sell well here, and idling drop axles are used even on heavy haul.

 

You still looking for a job? Try PI&I Motor Express ( piimx.com ) and one of their terminals is in Detriot.

 

They're Teamsters union, so probably a lot of driver complaining.