Boat trailer sway?

I hope this is the right forum for this question...

I just bought a 1988 suburban to pull my X30. I noticed that it seems to have a pretty significant sway to the vehicle while towing. I've towed the boat before with an '00 grand cheroke and it seemed to have less sway than the larger suburban.

Anyone have any suggestions? Do people install sway controls on their boat trailers?

Thanks,
Chris

You need to look over your trailer before you tow again.
Make sure you don't have a low tire.
Make sure one of your axles didn't shift.
If your towing with ballast, make sure you have some up front. Too much weight in the rear with make a trailer sway.
Is the trailer hitch higher now? If so, this could also be a problem. Make sure the trailer rides level.

How this helps, Joe

also if you are speeding slow down.

Some of the 02 Mastercraft trailers had torsion axle delaminations that can cause these types of problems. You should check this out. Inspect both wheels of your trailer on each side closely to see if one is raised higher; it is real obvious if the boat is off the trailer. I understand they changed the manufacturer of the axle as a result of the problem. They should replace at no charge under warranty if this is the problem.

It is an '02... and I'm only doing 55-60 when pulling the boat. Not THAT fast at all.

I'll have to check that out. Its definitely more noticeable when going downhill if that makes any difference.

move the neck (the pole where your bow ends up) on your trailer forward to move the weight forward only small adjustments can make a big difference.

Try drinking only 6 beers instead of the traditional half-rack. This should help with sway control? J/K

You may want to look into a weight distributed hitch. GM recommends using one when pulling over 4000 lbs. with a factory hitch setup.

Sounds like you should also look into checking out the tow vehicle. You said that the Burb was new to you & the boat towed better, with less sway when using the Cherokee. You may have some suspension or bushing issues on the older vehicle.

I've experienced this as well but on a Maristar 210, the trailer axle was too far back and there wasn't enough tounge weight which causes a very dangerous sway at higher speeds. Check your tongue weight.

I had a prostar 205 99 model. Single axle trailer and it would sway at higher speeds, around 70 mph. It swayed really bad on me once and that was all it took. I never went faster than 60-65 after that. I was towing with a 2000 Explorer. I noticed the same thing when I traded for my 03 Tahoe. I'm assuming it's a dual axle trailer under your x30. If it is, you shouldn't get that much sway even at interstate speeds- 65-75. May be a trailer problem cause I don't think it would be the suburban. You have to get that checked out by your dealer, it could cause serious problems.

I had a friend that towed a trailer with a Ford Expedition. When ever he got to 65 the trailer started to sway. In the end it was the tires on the vehicle. Changed tires and he was off and speeding again.

I think it definately depends on the trailer, because I tow my 90 Prostar with a 99 G Cherokee and it tows like a dream even at 75 mph.

If not already done I would immediately install Bilstien shocks on your Burb. There are no other shocks that will control the sway without going to a really high end shock. For the street they are as good as it gets. They are around $215 for a set of four and can be installed with simple hand tools although they are stiff and may require jacking up the truck. You will notice a major improvment in the vehicles handling both towing and unloaded. MacNeil's has great prices on the shocks. It also appears your truck uses four shocks in the front is this true? If so I would only replace the two main shocks and you will be set.

Trailer sway is caused by improper tongue weight. Does the Suburban sit higher than the Jeep? Make sure the boat is level, and if that doesn't work, move the boat forward on the trailer.

As long as the boat is correcly positioned on the trailer, correct tongue weight and so on, does it really matter if boat is level?

Isn't the tongue weight the same whether the trailer is tilted, say, forward. Seems to me that the same amount of weight is still behind and in front of the axle, level or not?

But I may be missing something? Would be really curioius to know the answer as I just got a new trailer that sits higher than the old one / is tilted forward. Will flip receiver to get level if it matters.

I'm not sure that it makes a difference being level, but it sure looks dumb if it isn't!

Unless the wheels on the trailer are at the very very back (no weight behind them), being level makes a huge difference, especially on a tandem axel trailer.

Shocks make little to no difference in sway. Sway bars, control arms, torsion bars, etc all have a much larger effect.

Chris Baker, can you clearify a few things for us please, to us help solve your problem.

1: what type of trailer is used under your boat, and have you experienced this vehicle sway with any other vehicles?

2: what type of Suburban, 3/4 or 1/2 ton, and 2 or 4 wheel drive? Is it lifted or lowered?}

3: How many miles are on the truck?

4: Does the vehicle sway side to side or is it trying to change lanes?

The tongue height will mostly effect how the brakes kick in. I am not going to get into the physics of it, but within a reasonable tolerance the tongue weight will not change. With the same boat as I had my friend used to tow with a lower tongue height then myself as he liked his brakes to kick in at a different time. The difference was about 4 inches lower, than my leveled trailer. The trailer tongue height should be roughly correct at about a 4 inch drop for a stock 4 wheel drive.

If a Grand Cherokee towed the boat just fine that points towards the Suburban not the boat or trailer. Chris can confirm this one. Although tire pressures of the trailer or truck can affect things dramatically, let alone tires themselves.

If the Suburban is a 3/4 or 1/2 ton is only so important but 2 or 4 wheel drive does make a difference. In 1988 Chevy used a solid axle under the front end of the 4 wheel drives. This alone will make them drive worse compared to a 1992 or newer 4 wheel drive or an older 2 wheel drive.

"Shocks make little to no difference in sway" I am not trying to be mean, but must ask for what reason you would say that? Have you owned a Suburban? Shocks make a huge difference in the way a vehicle handles in both ride and swaying, probably 50% is shock controlled. Sway bars do affect the vehicle very much also, a 3/4 ton has sway bar on the front and a 1/2 ton has a front and rear sway bar, but unless the link or bushing is broken they rarely ever cause a problem.

Perhaps I was a bit blunt in the statement that shocks make little to no difference in sway. I should have said that if the vehicle is driving fine without the trailer, then the shocks are likely not the only cause for the sway.

I have owned a Suburban, two of them actually. One 4WD, one 2WD. I made the mistake of putting a big lift on the 4WD and proceeded to break parts evertime I went off-road. Good truck, but a little too heavy to make a durable off-road vehicle unless you really go all out with bracing. Anyway, my statement came more from the geometry of suspension systems and the function of shocks as dampers. New shocks will have little effect on body roll or side to side motion (what I think of as sway), but I do agree with Peter that worn shocks will allow the springs and suspention to bounce around more and feel like sway.

Peter, would you agree that the stationary tongue weight will not change by a large amount when the height is moved up and down a couple inches, but a couple inch change will cause a significant change in the weight the vehicle sees under braking? (what you said above about the brakes suggests that, but I wanted your opinion.)

Found a site that has a lot of info on trailers, trailer height, tongue weight, towing level vs not level, tire pressure, sway, etc. Might find it useful. http://www.etrailer.com/faq/trailer-towing-tips.asp