Ok I have a 1988 GMC 2500 van dura that’s just out of control at 55+mph with my 4500lbs Formula F233 behind it. Like fish tailing so bad that it gets the back end of the van to start breaking loose on the Hwy (very scary) anyway has any one used a sway bar on a setup similar to this.

Should i get 1 sway bar or 2 the salesman says 2 ???? Or is there something else I can do to stop it from slinging back & forth besides new 8 ply tires the boat is close to done but I can't tow it yet???

They will not help with that kind of sway I do not think. I would try to change tires and maybe get a load sistributed hitch.

Jon

How much tongue weight on the trailer? If it is too light you will have that problem. How about the rear suspension/tires on the van? Good shocks? Springs strong enough to carry the tongue weight without excessive sagging? Load range D or better tires? All these may contribute to the problem. Do you use a weight distributing hitch? More data needed but few boat trailers need sway bars if everything is set up correctly.

A front bar might help. A rear bar will help keep things in line. Get one from a junk yard. There should be all the holes you need to attach it already. Also think about air bags in the rear. They will stop the sag and hold things tight back there. They can be deflated when not in use so the ride does not suffer. The tires will help but the ride will be harsh with no weight in the back. I use a bar and the bags and had no problem when I towed 10,000lbs

SecretF223.......I agree with Jon. The sidewalls on trailer tires make all the difference in the world. I swear by the Goodyear Marathons (although very expensive).

I second the air-bags. I will not tow without them now; unless I buy a dually.

Last month, a very good friend of mine was towing his 25' Boston Whaler (Walkaround) behind a new Chevy 3/4 ton p/u (4wd, Duramax 4 door) and the boat started fishtailing. End result was a total loss on the boat, motors, trailer and truck.

He has logged more miles towing boats than I have probably ever driven without a boat, so experience was not the problem. Once the fishtailing started he tried everything to no avail and finally rolled the boat and truck. Luckily bumps and bruises were the only injuries.

OK, while we are on this... I want to confirm. Is the best way to curtail a fishtail, to accelerate??

Secret F233

Give us a call..
I believe a pair of Air Lift springs will cure your problem

Performance Motorsports Tech
1-866-PMTCHIPS

I concur with everything Laster said. First you need to set the tongue weight properly. A good starting point is 10%. So in your case 500lbs. Be certain all tires are in good shape and inflated properly. A 3/4 ton truck should not need any modsifications for a boat that size, so before you spend teh big bucks start with the simple easy things first. Also, if you are using a weight distributing hitch on a light set up like you have that may the cause as well. Please provide more info so taht we may help you further.
Shane