Surging/Lunging Trailer while in tow

[James Cherry]

Hello all,

First I 'd like to say that I've enjoyed this site for quite some time.  There seems to be alot of nice, positive people who I really hope to run across during our outings.  

Having been a tent camper for many years, we finally bought our first popup a few weeks ago and we took it out on our first weekend outing.  We had a great time learning about the camper and had to chuckle everytime we did something out of sequence or such that I remember a post on this site, that had I paid more attention, would have saved me much time and effort.  However, it was a great trip and we enjoyed it very much. So much that we didn't want to leave the campsite - like kids in a candy store!

With that said, I do have a concern to post and hopefully someone can give me some guidance.  The popup we bought is a used 1999 Coleman Utah that weighs in at about 3000 loaded.  I'm pulling it with a 2004 Ford F-150, 4-door  Super Crew with a 5.4 liter engine.  The trailer is hooked up with a reese type hitch and has electric brakes.  The truck/trailer are level. The truck easily pulls the trailer and the trailer tracks beautifully with no sway.  The problem is the trailer seems to surge forward and back.  It surges on smooth roads and more so on rough roads, expansion cracks, stop and go traffic, etc.

I've experience pulling boats, horse trailers, hay wagons, and so on, and have never experiences such an annoying behavior.  Any thoughts?

Jim

[SpeakEasy]

Here's a thought. The idea that comes to mind is a partially-full water tank. I don't know how big your water tank is, but suppose it's 15 gallons. If it has 10 gallons of water in it, that's 80 pounds of water sloshing back and forth. This could definitely cause the sort of surging you're talking about. If I had to bet, I'd bet on that. You're better off emptying your water tanks for traveling.

[flyfisherman]

Jim - was having a problem deciphering the term you used ... "surges".  At first I was thinking along the lines of when you were braking but don't believe that has anything to do with it.

My previous popup was a '96 Coleman (Fleetwood) "Yukon" that had the front storage trunk. This model, along with some other Coleman models of the era, were notorious for a light trailer tongue weight. If one was not careful about loading cargo and having enough weight on the tongue, it would do some odd klunking, like maybe the trailer was searching for a balance; but usually this was accompannied with some serious trailer sway.

That's about the best I can offer ...


Fly

[James Cherry]

Thanks guys for the great input!  I've been giving it some thought and think maybe it's a bit of both as in,  partially filled water tank and the light tongue weight - let me explain,  The lunging was greater enroute to my destination than returning.  I've a 20 gallon water tank with another 6 gallons in a separate water heater tank.  Also, the front trunk was nearly empty as most of our stuff was either in various cabinets inside the trailer or in the back of the pickup truck. So, between the water sloshing around and the light tongue weight it did seems to be "balancing on a pivot" and very confused.

When coming back home, the water tanks were empty and the lunging was still present but not nearly as bad as before.  We'll be heading out this weekend to a local campsite and I will certainly be loading up the front trunk and holding off on filling the water tank until I get there.  I'll let you know how it goes.

Thanks for the great input.

Jim

[tlhdoc]

If your water tank is FULL it isn't a problem, it is the partly full tank that causes problems when towing.

[NeonHomer]

I remember riding with my friend who is a truck driver, and he delivered dialasys fluids. Most of these fluids were in 55 gallon plastic drums, each drum weighing approx 600 lbs... times this by 40-50 drums in this truck (was a 2002 Frieghtliner Century Class S/T with a 45' trailer)   On stopping, you could DEFINATLEY feel the liquids in the drums sloshing around.

He also carried other fluids in other containers....gallon jugs, quart bottles, and dry supplies...   This "slosh" almost caused an accident. He was driving a bit to fast on a wet road.. he hit the brakes, and the truck stated to slow.. until the liquid hit the walls of the drums.. then he went THROUGH the light... luckily, the guy coming the other way was on his cell phone and didnt pay attenton to thelight....

The lesson? Either fill your tank(s) completely, or drain them.....

[mike4947]

It also depends on where on the trailer the water tank is. In front of the trailer axle and it will contribute to tongue weight. Behind the axle and it will subtract from tongue weight. SInce the water heater is usually in the front trunk it pays to run that full even if the main tank is empty.

As my favorite rant goes....WEIGHT THE TRAILER AND TONGUE
 
FLeetwoods with front trunks are notorious for not having enough tongue weight (10-15%) and in later years Fleetwood predrilled the trailer tongues for friction sway controls at the factory and many dealers would not let one off the lot without one installed.

[MnStar]

FLeetwoods with front trunks are notorious for not having enough tongue weight (10-15%)

Can you clarify that? Doesn't make sense to me. Seems like any camper with a front trunk would distribute weight onto the hitch (unless people left them empty, which isn't likely to happen).

Unless....we are talking about axle location.

For example....my Starcraft has a front trunk. But, the axle location ignores that...in other words, the axle is place half-way along the length of the trailer, ignoring the front trunk.

(My camper has an 8' box; add the front trunk to it and you have ten feet) But the axle is not centered on the entire camper; it is centered on the "box".

We put considerable weight in the front storage compartment. The owners manual says no more than 200 pounds, I'd say we are close to that if not more. Hey, it's  a 2x2x8 foot space....we cram all sorts of stuff in there.

Bottom line...While we have to watch hitch weight (by not putting too much junk in the front trunk) we don't have to worry about trailer sway, because the camper load is transferred to the hitch, if anything.

So, my question is this...does Fleetwood have a design problem when it comes to axle location?

[mike4947]

Fleetwood's front trunk models are limited to 150 pounds to start with and if you can find older brochures (they finally realized there was a problem for '05 and redesigned some floor plans) you'll see that trailers with the front trunks had tongue weights below in some cases 6% off the show room floor and several models over the years could not be loaded to get enough weight on the tongue to tow safely.
Several years ago Fleetwood started predrilling the trailer tongues at the factory for mounting a friction sway control and many dealers would not let one off the lot without one installed. So at least the folks could get the trailer home without major sway issues.
Jayco, Rockwood & Flagstaff designed their trailers with trunks to tow empty or loaded and still be in the acceptable tongue weight range.
 
JMHO, but the low tongue weight issue was just another bad engineering decision, like ABS roofs and panels, and having a front trunk that leaked on a goodly percentage of trailers and having the floor extend beneath the front truck to make repairs costly and difficult (at least they redesigned the front trunks now to be seperate units with their own flooring. Only took them about 5 years to figure that one out) Also they finally replaced the roofs and end panels with more appropriate materials and have redesigned a few florr plans and deleted other with the low tongue weight issue.

[MnStar]

Several years ago Fleetwood started predrilling the trailer tongues at the factory for mounting a friction sway control and many dealers would not let one off the lot without one installed. So at least the folks could get the trailer home without major sway issues.
Jayco, Rockwood & Flagstaff designed their trailers with trunks to tow empty or loaded and still be in the acceptable tongue weight range.

JMHO, but the low tongue weight issue was just another bad engineering decision, like ABS roofs and panels, and having a front trunk that leaked on a goodly percentage of trailers and having the floor extend beneath the front truck to make repairs costly and difficult (at least they redesigned the front trunks now to be seperate units with their own flooring. Only took them about 5 years to figure that one out) Also they finally replaced the roofs and end panels with more appropriate materials and have redesigned a few florr plans and deleted other with the low tongue weight issue.

Thanks for the reply, Mike.

[Camping Coxes]

I'm not a "guy" type and don't know much about the trailer weights and tongue weights, etc., but we had a similar problem.  When my husband would barely start to appy the brakes, the trailer would lock up the brakes and start sliding.  Other times it wouldn't brake at all and nearly pushed us through an intersection, ending up somewhat sideways and causing the drivers around us to have to go home for an underpants change.  We took it to the place that installed the Prodigy brake controller about 8 months before and they tested the controller, and lo and behold it had become defective, sending all kinds of weird signals to the brakes.  The warranty covered the unit, they installed a new one and the problem was solved.