5th wheel fishtailing

[bdoss03]

I have a 2005 1/2 ton Chevy Z71 p/u and a 2003 22ft Komfort 5th wheel trailer that I purchased about
2 months ago,  I get some fishtailing in the trailer while traveling down the freeway and if a semi is in front of me or coming along side of
me, also with even light side winds.  is there something that I can do or that I am missing?

 

[Gary RV_Wizard]

Fifth wheels should be very, very stable and fishtailing or sway is most unusual.  Sounds like there is inadequate weight on the kingpin (hitch).  On a fifth wheel, at least 11% and as much as 18% of the total trailer weight should rest on the hitch for proper handling.  The first step is to get your rig weighed, axle by axle, to determine total weight and how the load is distributed.

Do you usually travel with water in any of the tanks (fresh, gray or black)?  One or more of your tanks may be behond the trailer axles and water (which is very heavy) maybe causing an imbalance.
 
Your half ton Chevy may be a bit wimpy too - half tons are made to ride and handle more like passenger cars and sometimes  some stiffening in the rear will help keep heavy tows in place. The addition of air bag assist (Firestone Ride Right or similar) sometimes helps. I wouldn't jump into that, though, without the weigh-in and some further discussion.

 

[Ron]

Sounds like you may be exceeding your truck weight limits.  Suggest you get the truck and trailer weighed and confirm you are not exceeding the GVWR or GCVWR of your truck.

 

[2006F350]

When you are hooked up, how does the truck/trailer sit? Trailer nose high or low, or pretty much level. You want it level or a tad nose low to get the pin weight up where it should be.

I agree with the others, your truck is probably underrated for what you are pulling.

Larry

 

[Carl L]

I have a 2005 1/2 ton Chevy Z71 p/u and a 2003 22ft Komfort 5th wheel trailer that I purchased about
2 months ago,? I get some fishtailing in the trailer while traveling down the freeway and if a semi is in front of me or coming along side of
me, also with even light side winds.? is there something that I can do or that I am missing?

The Komfort 222FS current model is a rather heavy short fiver, with a 7000 lb dry weight and an 8100 gross vehicle weight rating.  With out a engine size it is not possible to determined your truck's tow rating, but according to the Trailer Life tables, the only GMC 1500 that would not be overloaded by your trailer is the 1500 Crewcab HD with the 6.0L diesel. 

If that is not your rig, and you are experiencing instability, there is no cure.  It is time to get a new truck.