Gooseneck vibration

[snoball]

Ever since I bought my 35 ' double tandem I get a pretty serious vibration around 70. Faster it goes away and a little slower it goes away, with no real consistency. Seems to be worse when it's not heavily loaded, new tires on truck(did with old too), and trailer tires are all visually in great shape with good psi etc. Checked all drivelines in truck thinking it could be a driveshaft problem but all seems good. Any thoughts?

 

[Humpy]

Can you hook it to a buddies truck see if it does same thing? Also are they bias or radial tires on trailer?

 

[mdo817]

Re:

New trailer or used? Leaf springs or torsion axles on trailer?

 

[snoball]

http://bigtextrailers.com/25gn-heavy-duty-tandem-dual-axle-gooseneck/

This is the model.

 

[ecoast]

sounds like something is setting up a harmonic at certain speeds; maybe move some of the rear duals around, and re-check balance

 

[CHASMAN9]

What kind of tow pig do you have? If it's a Gmc or Chevrolet, might want to look at a bad Unibearing.

 

[Toddy]

Trailer tires. My tacoma does the same thing and i know its the tires. Loaded will help knock some of it down.

It is just doing it with trailer hooked up right? If so no question it is in the trailer tires. Wont take much to transfer a little vibration 20' back into a big vibration at the truck. Gooseneck will be worse then 5th wheel also.

Swap tires around or take it and have them all balanced.

 

[grcthird]

Agreed, out of balance or not balanced at all trailer tires will vibrate the tow rig, may have a bad tire. Check to see if one has a spot on the tread that is higher or if the tread turns to one side instead of being straight. I just had to replace 2 on mine for this. Probably going to have to do the other 2 soon.

See how the tread isn't flat and balloons up in the middle? This particular tire is bad, some trailer tires look like this normally.
(Third picture is my spare, same tire and pressure. Tread is flat across it.)

 

[snoball]

Thanks for the input. I am going to try balancing the tires and try another tow rig and see if it still does it. I have the trailer set up flat when loaded. Is that correct or would the tongue being a little higher or lower be better?

 

[ecoast]

flat allows the equalizer between the axles to work best

 

[Addison66]

If you want I can run my trailer up one day and you can pull it then swap trailer tires if needed. I bought my tires from Dean about 2 months ago so there new.

 

[snoball]

Thanks Scottif the tires don't help once they are balanced I'll take you up on that.