Sway solution for M1070 that was converted to haul not pull

[Tattooed farm boy]

I stretched a M1070 50 inches and put a 26ft ag box on it. Overall length is now 40+ ft, and tare weight is 47,000 now . The truck rocks from left to right , I'm not lookin to replace suspension their must be a simple inexpensive fix . Tried going to a single valve height control but not the issue , any advice would be much appreciated ..

 

[Shark Bait]

Could it be "twisting" in the section that was extended? Any pics of the engineering?

Dave

 

[Hummermark]

Is the rocking all the time or only when loaded at full load?

 

[DanM7890]

I can't contribute just wanting to say what an awesome rig!

 

[paradeduty]

I'm not a "heavy mechanic or engineer" but do the heavy trucks with air rear suspensions use any type of sway bars? Can't imagine that it is as simple as a shock-absorber upgrade as that would only dampen the sway, not eliminate it.

 

[Tattooed farm boy]

I don't think twisting of the frame is the issue the whole truck liens it depends on the crowning of the road to full or empty it does lean. Perhaps sway bar is the answer not convinced though . Here is a picture of my cousin who has leave springs but the box is only 24 foot with a stretch and his does not have that problem

 

[Shark Bait]

A thought just occurred to me. When I first got my HET it wanted to swerve back and forth slightly at the higher end of its low speed spectrum. I believe with the weight of the bed and being extended this swerving could be transmitted to swaying. The issue was the rear steering axle was a little out of line with the front axle. Basically fighting each other. I realigned it the best I could and not had the issue since. I don't know this will help but may not hurt to look at?

Dave

 

[Tattooed farm boy]

Dude your totally right ! I can see the back axel is way out of whack , the bottoms of the tires are pigeon toed in . So how exactly or what exactly did you do? Anything with that steering rod Tying the back wheels together ? Would it be a bad idea to maybe run a chain from the frame to the axels to minimize some of the lean or not such a good thought ? Thanks for everything Dave I appreciate it very much !

 

[Shark Bait]

I got my front as straight as possible then got a tape measure on the rear to figure how far off it was. I took loose the steering tod from the rear steering box and used a hi lift farm jack, like the off road 4x4 guys use, to even it back up, then adjusted the steering rod ball joints to fit back to the steering box. Been fine every since.

Dave

 

[Gunzy]

A simple thing I have come across before is tire pressures. You may want to run them closer to or maybe at the max listed on the tires.

 

[Hummermark]

Hi mine had a wander at the top end speed front axle wheels pointing straight ahead rear steer axle was not.i set it up as manual which says that when axle 1 is in straight ahead position the rear steering drop arm(pitman arm)should be inclined to the frount at 9 degrees and the frount pitman arm should incline backwards 6 degrees. I used a magnetic angle gauge to do this.
with drop arm at correct angle adjust drag link till axle 4 stear axle is in the straight ahead position.

set it up as manual no more wander

 

[TNriverjet]

I can't contribute just wanting to say what an awesome rig!

X2! Wow, just wow. I think the dropped visor makes it look very aggressive. I like it. Hoping your rear steer axle alignment works out the issue.