I think my leaf springs are pretty weak, I bought this truck to pull a Travel trailer, it has 193K. Rear susp drops quite a bit when hitched to trailer. I am also plagued by the trailer swaying and trying to steer the truck from the rear. Near undriveable on uneven road surfaces/tight curves.

I am planning on putting on a set of LP35 Hellwigs (3500#) progressive helper springs. Am interested in opinions as to the effectiveness of this before I shell out $300 and skin some knuckles. Everything that I read points to the leaf springs as the culprit on the sway issue. Thanks to any that can help,
Darwin

 

Travel trailers are funny animals. Many different things can cause them to sway and most of them have nothing to do with the truck. You may find you hook onto one trailer and it pulls fine and then hook onto another and it sways like crazy. If your rear end is squatting I would definitely pick it up as you plan to. It may or may not fix the sway, but will be better handling for sure. Sometimes it is as simple as moving more weight onto the tongue or shifting weight forward within the trailer. Good luck with it either way.

 

First, check your tires. Make sure they are rated for the load and inflated properly.

Second, check the actual weight of the trailer. If you have a scale near you, hook up and get there. Make sure you are not over weight.

Third, get a weight distribution hitch. Get some of that toungue weight on your front axle.

I would do all this before I messed with the springs. Just my $0.02.

 

X2 on the hitch, I was assuming he already had one. If not it will explain the rear end sag etc.

 

Thomabb,

Tires are new, 12 ply radials, rated for load. I do have a weight distributing hitch and I run it as tight as I can. As far as the trailer weight I am using the Mfgrs specs and adding the weight of water and a fudge for dry cargo. The truck is rated for 12500# so I'm thinking I should be well within it's capacities.

I used to pull a 7500# race trailer behind a 37' motor home and I never even felt it.

 

What kind of shocks do you have and how old are they?

 

I'll bet if you scale the trailer you will find it is closer to what your truck is rated for. Travel trailer manufacturers are notorious for under-estimating the weight of their trailers. I have a 5th wheel that is supposed to be 8600#. It weighs in over 9500# empty.

Do you have the factory overload springs on your truck? Does the trailer set you down to the overloads?

 

your truck is rated for 12,500 bumper pull?

 

My truck is rated for #13100 frame hitch towing capacity. Pretty sure I'm not over that. As for shocks, I can't tell, they're certainly not Bilstiens which I put on my Motor home

 

If you're shocks are worn out or poor quality, that could contribute to your problems with a heavy load. I'd put a set of adjustable Rancho 9000XL shocks on the back that you can crank way up when loaded heavy.

 

If you are seeing a lot of rear sag, I'm leaning towards the trailer being heavier than what is on the tag and/or the WDH is too small. You should be pretty close to level if the WDH is working correctly, even if you have worn out rear leafs. Does the nose of the truck squat at all, or does it rise when the trailer is on the ball? If the WDH setup is right, both the front and back of the truck should squat a little under heavy hitch loads.

 

Either your tongue weight is too high or your springs are shot like you suspect. I would get weighed at the scales to confirm where the problem is. Weigh the truck and trailer together on a 3 axle scale so you get the steering, drive and trailer axles as three separate weights. Then drop the trailer and weigh the truck by itself and get the steering and drive axle weights. You will then know what your trailer weighs exactly but more importantly you will know how much weight is added to your drive axle. You will also know how much weight your distribution hitch is moving over to the front axle. Should cost about $10 bucks for the scale fee which is a small price to pay for the knowledge you just gained...

Personally I like air bags because I have a little more adjustment to get the trailer to tow level. I find that my brake system is much more effective when the trailer is level. I don't know anything about Hellwig's spring kits but their sway bar is awesome. If your '99 doesn't have a rear sway bar then you might want to look at the one Hellwig offers.

 

Lots of good suggestions here. But it's pretty hard to give advice when we cannot see it, and you have not weighed it. But some added thoughts...

I seriously doubt that your springs have gotten weak from age. Not to the point of causing sway. But your shackle bushings could be worn out, and that directly causes sway.

You might be too light on the tongue. You will only know that by weighing the trailer, and then weighing the tongue. You need at least 10% on the ball, and 15% will help with problem prone trailers. Some simply are not designed well.

Check the capacity on your WD hitch. There are different levels. If yours has 750lbs spring bars, they are not correct. You should be able to easily lift that trailer if the spring bars are correctly sized.

 

Can you give us a side shot of your trailer hitched to your truck? I would like to see how your spring bars are set. I would discourage you from making any changes just yet. There is too much we don't know.

I would note there are huge differences in the effectiveness of various brands of hitch set ups. I would also suggest you run your set up across a scales and get actual weights. Until that is done, it is hard to do more tha generate hypotheses.

Steve

 

Honestly, it sounds like a Weight Distribution Hitch problem. If you have rear end sag your WD hitch isn't doing it's job.

I tow a 6500-7000 TT with a f150 and my truck and trailer sits LEVEL. I have 1000 lb bars.

If your trailer is truly 10,000 lbs. You need 1000 lb bars minimum. Maybe, probably, 1200 lb bars.

Some notes about the WD hitch set up. The ball on the hitch head should sit 1.5-2 inches ABOVE the uncoupled, level Travel trailer coupler. This often over looked fact is in your hitch instructions and is Critical for the WD bars to obtain the proper leverage they need.

Second, your hitch head should be tilted forward (away from the truck) at about 15 degrees. Again this is for Leverage.

Third, what brand of WD hitch do you have?

I highly recommend some type of sway control, AT LEAST DUAL friction Sway control.

Here is a picture of my trailer coupled with dual friction sway control. I am sorry for my ugly feet being in the picture though.