Boat bouncing on trailer

[Rob 8043]

For many years I have towed my 21' mariah on a chariot trailer, I purchased both new in 1996. My original tow car was a ford expedition and I never had an issue, in fact at times I even forgot the boat was being towed at all. Last year I purchased a Jeep grand Cherokee diesel, which I use as my tow vehicle.

I'm having an issue now, that I cannot determine whether it is the Jeep, or the trailer itself, but when I tow, and go over a bump it feels like the boat is bouncing on the trailer. Yesterday, on the launch ramp when trailering the boat, I made an effort to make sure that the boat was as far forward as I could get it on the trailer, and I tried using a transom strap from the bow ring to the trailer (which I have never had to do before). This seemed to help a great deal but I could still feel and hear what sounds like the boat bouncing a bit.
.

Any suggestions would be most appreciated.

Rob

 

[Scott Danforth]

by law your transom needs to be tied to the trailer and there needs to be a safety strap from the bow to the trailer

you may be hearing the draw bar slop around in the hitch carrier.

 

[Starcraft5834]

As Scott said.. assuming your securing the rear end of the boat to the trailer?? when I had my cuddy, we strapped the rear end transom (ski tow) rings, it never bounced...

 

[Rob 8043]

I definitely tie down the rear transom; what is a draw bar? Any thoughts on why there seems to be a different towing experience based on the Ford vs. the Jeep?

Thank You

 

[MTboatguy]

Drawbar is the ball mount that you slide into the hitch on the tow vehicle, it may not fit as tight as it did on your other vehicle which is allowing enough movement so you hear it rattle a bit.

 

[ahicks]

I've found that bouncing is nearly always a boat that is not hard against the front bow roller/stop, and not secured.

What happens is the front of the boat trailer is flexing because it and the boat are not secured properly. Eliminate that by securing the front of the boat to the trailer in a manner that won't let that happen.

 

[Lowlysubaruguy]

Has your winch post slipped forward or backwards one of my boats gets shifted every now and then and causes the same thing I think its usually rearward a couple inches. That boats winch post is held on the trailer with u bolts and there not quite enough to handle every force that happens on the road.

 

[Rob 8043]

Thank you everyone for your input. One of the things I found out was that I have been under inflating my tires by about 10 lbs of pressure, will remedy that before next trip. I have purchased a strap for the bow, and will add that.

I have noticed that in the past I do not seem to get my boat all the way up on the trailer. When we pull it out of the water I do get it all the way up on the roller stop, but as soon as i drive the trailer up the launch ramp the boat seems to slide back a bit, are there any suggestions on how to get the boat to stay as forward as possible on the roller when leaving the lake?

Finally, I also notice that there is a good 1/4 to 1/2 inch play in the draw bar any tricks to tighten that up?

Thank you

Rob

 

[ahicks]

Rob, that gap you're getting when pulling the boat out may be because the trailer is in too deep when you are pulling it up to the stop. The back of the boat is floating so high with the bow up tight on the trailer, that when it finally settles down on to the rollers/bunks the bow is no longer against the roller.....

Regarding the draw bar, there are devices available to kind of clamp it in place. I've found that if the tongue weight is right, and the boat is hard up against the bow stop, that rattle is pretty much gone.

 

[dingbat]

Finally, I also notice that there is a good 1/4 to 1/2 inch play in the draw bar any tricks to tighten that up?

hopefully your over estimating the clearance in the draw bar and it’s more like 1/16-1/8” clearance.

If not, are you sure you have the right draw bar? Some receivers use 2” draw bars, others use 2-1/2” draw bars.

My departure routine after leaving ramp....snug boat to bow stop (with winch), install and tighten turn-buckle (tie down), then release tension on winch cable

 

[MTboatguy]

1/4 to 1/2 is way to much play in the draw bar, like said, it should be no more than an 1/8 inch. Something is not right if you have the amount of play you are claiming,

 

[garbageguy]

I think some pics of your setup would help you get help

 

[Rob 8043]

My boat and trailer are stowed across town, so I can't provide pics, I probably over estimated the gap on the draw bar, but there is play in the receiver once I lock in the draw. Going to lake havasu from vegas in 2 weeks, and I will be putting all these suggestions into play.

I have always put the trailer on the launch ramp deep, so I could winch up the boat to the roller easier, I guess I have probably defeated my purpose.

I will report back.

Again, thanks everyone for your help

Rob

 

[bigdee]

The Jeep is a unibody vs the Fords body-on-frame. Sounds will transfer to the unibody much more than a framed vehicle. I have Jeep GC and the small amount of play in my drawbar drove me nuts until I eliminated the play.

 

[Scott Danforth]

I have more than once hammered in wooden shims for aligning doors and windows into a draw-bar and receiver that had a bit of play. need to drive the pin out with a hammer to get it free, however it stopped the clanging.

 

[bigdee]

I drilled and tapped 2 holes in my receiver,one hole on side and one hole on bottom. I used a 3/8-16 bolt in each hole to take up slack and used a jam nut to lock them in place.

 

[strokendiesel002]

I too have a Diesel GC. 2014 - the drawbar (hitch that slides into the receiver [receiver is what we see as the square piece with spots for safety chains and is bolted to the vehicle]) rattling can be heard at a wildly irritating level if you don't have enough tongue weight. It was like this in my 2008, 2002 and 1994 Grand Cherokee a as well. Our G.C.s have a considerably softer suspension than did your Expedition, which is why you may notice more "bouncing" than before. (This is assuming that you're boat is properly attached to the trailer, which is probably safe to do as it sounds like you've had it for some time )

You may consider air springs for the back, if you don't already have the auto leveling suspension. I don't have the auto level and will likely be installing the air springs soon as I pull a wide variety of things fairly regularly (3 boats, PWCs, 6*12 aluminum enclosed and even an open aluminum car hauler). And she squats pretty good with proper tongue weight. Anyone who wants to test the squat, figure out your tongue weight and normal load that would be in your cargo hold during travel. Go buy bagged sand from the big box store of choice, toss it in the back and go for a drive. You'll notice decreased braking ability and looser steering, along with having an idea for how much your vehicle will squat. From here you can decide if lifting the rear of your vehicle with air springs would help (it will) by having proper weight balance over the front and rear wheels.

I know the above isn't directly related to hitch rattle/ boat bouncing, but should be something considered as we continue to get smaller and lighter vehicles with higher power to weight ratios.

I hope you find the cause and can go back to worry free outings soon!

 

[Rob 8043]

How did you eliminate the play in your drawbar?

 

[jetboater]

How did you eliminate the play in your drawbar?

I use a Stowaway hitch tightener——about $18 on Amazon—-works great. Stainless steel and made in the USA.

I did change the nuts from the regular ones it came with to self locking ones with the nylon inserts

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

(not affiliated with them in any way—just a happy customer)

 

[Cat nip]

I have seen this caused by tounge flex and flexing of the actual hitch while within the recommended weight limits. To check have someone stand on the tounge and don't jump but move up and down and see if you can see anything flexing. And that should give you a better idea of what direction to go with fixing it.