07 W900L problems

toss a few numbers on the steer tires, also a scale ticket showing where the weight is when loaded might shed some light on the shimmy and shake

the power... got me, but i'd start by getting a shop to spit out an ecm read for you, typically not a bad thing to have on hand anyway

 

If you are indeed grossing 90,000 lbs. then you are putting about 13,500 to 14,000 lbs. on the steers at least. And assuming you are correct and the dealer just threw a set of cheap Chinese trailer tires(maybe even recaps) on there to make the sale, then bad tires are going to be your shimmy problem. When you drove it home it didn't shimmy because you haven't overloaded the tires yet.(actually you have my T-600's steer axle with a 475 Acert weigh's 11,200 lbs. bob tail) Now that you have got it loaded to 90,000 lbs. you have approximately 7000 lbs. on each steer tire that is rated at 4250 lbs. (trailer only tire rating). You might want to look into replacing them before you hurt or kill yourself(or someone else). When you replace them make sure they are rated at least for the maximum weight you will be putting on them. Cheapest is not always the best buy, and myself I am a big fan of over kill, I don't know anyone sorry they put 7000 lb. tires on a steer axle that never exceeded 12,000 lbs. I'm just sayin'....

 

how do you figure "then you are putting about 13,500 to 14,000 lbs. on the steers at least." just because your gross weight is higher does not mean your steers are automatically higher, 5th wheels are adjustable as well as how the weight is distributed in the trailer. (assuming tridem trailer as well in this setup)

it is possible that you have a bad tire causing the vibration you describe. you could try swapping your tires side to side and see if the vibration changes. also jack the tires off the ground and give them a spin and look for a bent rim or out of round tire. and check wheel bearing and kingpins for play

you probably already know this but mud in the rims if your pulling out of a feild can cause a pretty bad vibration as well.

as far as the power issue makes no sense that it would run great loaded and like a dog empty, i would start with the basics anyway pressure test the air to air check boots for leaks etc.

 

He said he's pulling a triple axle trailer, so I would assume that the extra weight over 80,000 that he is pulling is on the trailer, not the steers.

It's possible that you either threw a weight, or one of the tires has a belt coming apart. Have the tires spin balanced and see where you're at there.

I have never heard of a truck that can tell when it is loaded and empty, seems awfully weird that it is low on power when empty but fine when it is loaded. Personally I think it is in your head. A Detroit will speed up faster than a Cat will when both are driven properly, Cat's are slower to drop in rpm when changing gears than a Detroit is, I think since this KW is new to you that is what you are feeling.

 

"How I figured it" was the fact that if you increase the total weight of the vehicle by 50,000 lbs. or more some of it will be on the steers, no way around it, unless you stack all the product up on the very back of the trailer. I'm no grain expert but I'm guessing that's kinda hard to do. My WAG of 13,500lbs. ain't very far from his actual weight of 12,000 to 13,000. But as usual my point was totally over looked to point out that my estimated axle weight on a truck and trailer that I haven't seen was off by 500lbs. IF and only IF the tires in question are "trailer only" tires it will say so on the sidewall, which brings us right back to my original point, a "trailer only" tire is usually rated at about 4250lbs. and if he is putting 12,000 to 13,000lbs. on a pair of tires that are collectively rated at 8500lbs. then he is over loading each tire between 1750 and 1850lbs. KDub I understand you not wanting to throw more money at it without knowing for sure, but if you flipped them side to side and the pull is now to the other side, then that just confirms my original thought of a bad tire.(or 2). Is it possible there is something else wrong too? Yes, but in my opinion you have at least 1 bad tire. Once that is corrected you can look for other stuff, there will always be other stuff.

 

you are wrong that increasing your gross weight will increase your steer weight, (this would only be true if your 5th wheel was set too far forward and you never moved to the correct position) iv put a truck that was 104k gross on a cat scale before and the steers were only 11,300

this will be my last post as far as gross vrs steer weight on this subject to avoid argument.

although i agree on the bad tire.