Ok, so I recently hauled my toyota on a HD 25' gooseneck at 70 mph with no problems. The following weekend I get a call from a buddy whose truck had broken down and asked if I could haul it back to his house. I borrowed another buddies 35' gooseneck to haul the truck since it was much longer, a ex cab long bed 3/4 dodge. While pulling the 35' anything above 65 caused a horrible shake in the truck to the point of I thought it was going to tear the truck apart. It did this both loaded and unloaded and started around 65 both times and I was on different roads both times this happened. The truck has no shake without the trailer and when I told the buddy something was wrong with his trailer he claimed he doesnt notice it when he pulls it with his Dmax dually and said it must be my truck. He called me yesterday and told me he had just used it since I did and still didnt notice anything. Any ideas on what could cause the shaking. Could he not be noticing it because of his being a daully. It is a new dmax 4x4 dually with a flatbed.

 

Maybe a belt separating on a tire or no sway bar in the rear. I have a a intermittent wobble in my rig too. I am going to start by jacking the wheels on the rear and running the truck up to see if it is my tires. I had a shop look last year and they said one of my tires is bad...... they didn't mark it
I have replaced my D70 with a D80 if it isn't the tires I will have to check the drums but in my case it is intermittent

I 'am going to try a set of loaner rims and tires to make sure it isn't the rims themselves, I have had the wheels balanced with stick ons and then beads and now back to clip on weights

 

It doesnt shake any other time except for when I was pulling his trailer. The day after the haul i drove 120 miles at 70 miles and hour and never noticed it and I pulled my boat on Thursday and didnt notice any kind of shake.

 

Is your hitch off center ?

 

I know this sounds crazy, but just throwing it out there, is there enough weight on the truck? Are the wheels really far forward on this particular trailer? if the trailer is picking up on the truck the tail will wag the dog. lol

 

I dont think so, the trailer squated the truck some and when loading the truck we acutally parked it a little forward and set the truck down on the overloads to see if that was the problem. Still got the wobble but not as bad.

My hitch is as centerd as it can be I believe. My father in law and I installed it and he is a perfectionist when it comes to those kinda things.

 

Your ball is the recommended 4" in front of rear axle centerline, right ??

You said 35-foot trailer; is that 35-foot flat PLUS the neck, or 35-foot overall ??

What type axle arrangement on the trailer, single-wheel tandem, dual-wheel tandem, or tri-axle ??

Slipper-springs or that torsion junk ??


This "wobbling", is it a fore-and-aft surging motion, sort of like boom--boom--boom; or, is it more of a vibration ??

 

It is a 32' deck with 3' dove and it is dual tandem torsion axles. The wobble does feel that of a tire that is out of balance as it is more of a side to side motion. My ball is 3-4 inches ahead of the axle and as centered as possible. If a tire is out of balance or round on a trailer that size will it transmit the shake to the truck like that? Another friend suggested it possible has a busted wheel but I couldnt see that when I checked it out. The owner of the trailer is known to overload it just a wee bit. Think he told me he topped the scales a couple weeks back at right around 50,000.

 

Half the tires on the trailer could be square and I doubt you could feel it in the truck, nor would you notice a busted wheel until it came flying past.

I am not a fan of torsion axles; give me good old slipper-springs anytime.

50,000-gross is not at all unheard of with a trailer like that.

A broken-belt tire will wobble most at low speed, like 10-40 mph; once it starts to wobble, the slower you go, the worse the wobble.

From the evidence you have given, my verdict is that you are somewhat under-trucked for the trailer and you are just experiencing the harmonics of the mis-match.

Your truck feels fine at low and high speeds; it behaves okay with the smaller trailer; it only did it with the big trailer; case closed.

 

Torsion axles won't cause that, and there's nothing wrong with them if you can keep em out of sand.

 

Have you lowered or raised the gooseneck post to see if that changes anything?

 

Like Billut mentioned was the trailer setting level when it was hooked up to your truck? That is why I prefer the springs with a walking beam..

 

I think its something to do with the trailer, I have been pulling one about that size and have had no problems. I think the trailer has a tire or suspension vibration that you are feeling. The reason he isn't is because his truck has a softer ride and soaks up the vibration to point where he doesn't feel it. Just my .02.
DS79

 

I vote that the kneck was not adjusted properly. I have spent over a half million miles pulling a 30+5 and any time I switched to a shorter or taller truck the ride was bad till I adjusted the kneck properly. I would not own another spring ride trailer to use on our highways!!

 

I was thinking this too. I know if I get mud in my wheels and dont either clean it out or spin it out before I get on the road the truck goes crazy bouncing and I attribute this to the stiff suspension.

I did not adjust the neck for the sole reason that I was just borrowing it for one short trip 30 miles round trip maybe and didnt want to mess with the setting he already had it at.