they didn't cover this in trucking school

Wouldnt the front axle on a spread get the hard tire scrub if you were flipping a u-turn?

 

Anyone who "flips a U" with a spread axle trailer is a fool!

To expand on that thought....In my opinion anyone who "flips a U" with any trailer isn't too bright!
The stress that that sort of thing puts on suspension and the frame of the trailer is extraordinary and will lead to premature failure of the suspension and in many cases the trailer itself.

I have seen broken trailer frames from morons "flipping a U" with a loaded spread.

Tire scrub is bad if you turn sharp with a spread but it is really that least of your worries in the long run.

 

yep, hence a dump valve if you are forced to do that. in a hard turn the front outside tire catches hell. it isn't something you want to do if at all possible. it really can screw something up. but i guess if someone makes a wrong turn and gets in a bad spot, they may be forced to do it. after you pull a spread for a while you will hopefully avoid situations such as that.

mine is rigged a little different, i can dump all four manually, then i can chain up the front axle and only air up the back and keep the front off the ground, requires to mod the abs a little . gets about 1 mpg more when empty or light load. my trl isnt all aluminum. i can dump the rear axle from the cab. but i only do that when the front axle is getting in a bind. not something to do just for the heck of it.

 

It's real hard on a trailer if some idiot hand leaves an axle dumped with a load on not to mention what mr dot would say about it at the scalehouse

 

Not to insult the godfather, but a few times backing into a tight spot without a dump, the trailer/ front axle seemed to be twisting from the weight of the load and the angle of the truck to the trailer. This usually happened with the trailer i pulled with the super singles on it. Wouldnt this be equally as hard on the trailer and suspension? Id like to here your thoughts on this.

 

It's only hard on the tires when you hit the brakes.

A dump valve killing a trailer is a myth. Some people like to say that's the reason those junk Transcraft trailers would develop frame cracks. That's bogus because they would crack at both the front and rear axles, so it wasn't from "overloading" the front axle. You can't overload an air suspension, the Intraxx300 is rated for 30k per axle and at 120psi it will hold 30k period (trust me I know). If I'm loaded to the max weight on a spread (20k per axle) and I dump the rear all that happens is the rear axle dumps and the front axle bottoms out. That means BOTH axles are sitting on the bump stops inside the bags. Your not putting 40k on one axle and going to snap the frame in two.

For those who refuse to use dump valves and still choose to make tight turns here is a quote from Fontaine trailer.

If your trailer breaks because you dumped one axle, it was a POS to begin with. If the trailer manufacturer won't install a dump valve at the factory it's because they don't trust their engineering enough and should be avoided. Pick the right brand and they'll install whatever you want. Here's a beefed up Intraxx 300, installed as a factory option with the knowledge it's going to be severely overloaded will a full warranty with or without a dump valve.


A 3 bagged 300 will hold WAY over 30k per axle, and not one broken frame because of it.

 

preach on, jfaulk

 

I'm pretty sure they covered not hitting curbs at your trucking school.

 

NEVER hit a curb in school or test date..auto fail..i am a recent grad..we used 48' van.axel all the way back to closely simulate the turning radious of a 53'..note i said closely.i tested out on flatbed 48' spread axle..ran the vans empty and loaded to get the feel of wieght.over all i was happy with the training.but of course would of liked more.but they can't teach everything.in there time frame.had 20 trips.basically just to get ya familure with truck n basic handeling..only in the real world will ya get true exp..remember when you start the turn you control the intersection..make your self visable to all around ..

 

Jfaulk, nice info. Im usually using a benson all aluminum with 45-49k loads. Trailer weight (if scaled) 32-37 depending on the load.