car shaking when towing pwc

[marioana]

We have a 2012 infinity FX35, with a hitch installed on the frame. Because it is on the frame (and not on the bumper) and the car is so low, we had to order a adjustable ball mount (draw-tite part 1424) so we can have the required rise of 6'' ( we have a Karavan trailer) and the necessary length of the ball mount (normal one piece ones were too short).
We noticed that when we towed the jet ski, when accelerating or breaking the car started to wobble/shake. The wobbling was reduced after pulling the jet ski out of the water, but returned after a few breaks. We assumed that pulling the jet ski made the ball mount become fix, and breaking made it loose again. But the ball mount is not hollow and most of the anti-rattle devices require it to be hollow. Any idea how can we fix this(if this is indeed the problem)? Or any suggestions why the car would wobble/shake?

Thanks

 

[lckstckn2smknbrls]

Re: car shaking when towing pwc

Do you have enough tongue weight? It should be around 10% of the boat and trailer weight.

 

[marioana]

Re: car shaking when towing pwc

Do you have enough tongue weight? It should be around 10% of the boat and trailer weight.

tongue weight is 500lb, and the jet ski is 1062 lb and the heaviest Karavan trailer (don't know the exact model by heart) is less than 500lb, so I guess tongue weight is fine...

 

[H20Rat]

Re: car shaking when towing pwc

define 'shake'. Do you mean vibration, or do you just feel the trailer jerk around some and make knocking noises.

If its vibration, I'd look at tires first. If you are just talking knocks and bumps (nothing periodic), those are normal. With a body on frame vehicle, they still happen, you just don't notice them. In your case you don't have a frame (unibody design), so the normal trailer noises are amplified.

The anti-rattle devices are purely cosmetic in function, the rattling isn't bad, its just annoying.

 

[fishrdan]

Re: car shaking when towing pwc

tongue weight is 500lb....

On a single jet-ski trailer That's the tongue weight of a 25' cruiser....

Place a bathroom scale under the ball coupler (or trailer's jack) and see what the scale reads, that's the tongue weight

 

[ricohman]

Re: car shaking when towing pwc

I doubt the tongue weight is anywhere near that.
I would check the rise or fall of the ball mount. You may have have to much +/- caster.
And to much positve caster will shake a light load pretty easy.

 

[marioana]

Re: car shaking when towing pwc

http://www.etrailer.com/Ball-Mounts/Draw-Tite/1424.html this is the ball mount.

Do you have enough tongue weight? It should be around 10% of the boat and trailer weight.

Ups, now I read again the previous posts and figured out the confusion. I though you meant the ball mount tongue weight...I have no idea what is the actual tongue weight of the trailer and jet ski

define 'shake'. Do you mean vibration, or do you just feel the trailer jerk around some and make knocking noises.

The feeling we have is like someone is pulling and pushing the car...

I would check the rise or fall of the ball mount. You may have have to much +/- caster.
And to much positve caster will shake a light load pretty easy.

We did measure the height we need so that the trailer is parallel to the ground, but we will measure again, just to be sure...

 

[rbh]

Re: car shaking when towing pwc

If it's only during acceleration and breaking I would suspect you may have a bad U-joint.
Does it go away when you get up to speed.

 

[marioana]

Re: car shaking when towing pwc

If it's only during acceleration and breaking I would suspect you may have a bad U-joint.
Does it go away when you get up to speed.

It goes away for a while, but if we try to get over 60mph it comes back...

 

[jkust]

Re: car shaking when towing pwc

I had the identical issue with my snowmobile trailer this year. I bought it in 2008 new and has maybe seen 600 miles so it has mostly sat because we have had so much snow locally. When bringing one of my sleds in for service this past fall out of nowhere this formerly perfect trailer manages to vibrate the car like you are on a washboard dirt road. Of course we had no snow this winter so the trailer never actually got used again. The vibrating will randomley come and go throughout the drive with no rhyme or reason. It shakes so bad you think the SUV is going to fall apart. I have yet to figure this out as well.

 

[rbh]

Re: car shaking when towing pwc

OH, that kinda shake.
That push and pull feeling.
If things are loose, cup on ball, draw bar in reciever, you will get a push pull feeling.
For that matter if the trailers reach is not horizontal with the tow vehicle and is pointing down the weight transfer will be to the rear brakes and not totaly balanced for the front brakes as well.

 

[TyeeMan]

Re: car shaking when towing pwc

You say you have an adjustable ball mount. . . I have an adjustable "receiver" I use on my 3/4 ton GMC. My travel trailer (4500lbs dry) is one hieght and my enclosed snowmobile trailer (3500 lbs dry) has a different hitch hieght, so I use a class C adjustable receiver. By pulling two pins I can raise or lower the hitch about 8 inches.
The first thing I noticed on my adjustable receiver compared to a regular say 2" rise receiver is that the adjustable receiver has a lot of slop in it which results in some side to side play which could be mistaken for sway, or like you say somebody pushing or pulling the trailer.
If your adjustable ball mount has any amount of slop in it or fits loosely into the hitch on the car that is likely your problem and is just the nature of the beast.

 

[wvstriper]

Re: car shaking when towing pwc

Does your trailer have brakes?

 

[marioana]

Re: car shaking when towing pwc

Does your trailer have brakes?

unfortunately no

 

[Maclin]

Re: car shaking when towing pwc

Try keeping the tranmission in a lower gear, specifically keep it out of overdrive and see if the symptoms change.

 

[marioana]

Re: car shaking when towing pwc

If your adjustable ball mount has any amount of slop in it or fits loosely into the hitch on the car that is likely your problem and is just the nature of the beast.

But won't this damage the car?

 

[TyeeMan]

Re: car shaking when towing pwc

No it won't wreck the car. I should have used the appropriate term but couldn't think of it when typing my earlier post. The draw bar is what goes into the receiver which is mounted to the car. The original poster and myself have an ajdustable draw bar.
My draw bar has 2 parts, an L shaped part that goes into the receiver on the vehicle and the other part that the ball mounts to , , this part is held in place by 2 pins, the same type of pin that keeps the draw bar in the receiver.
On my draw bar the square part that goes into the receiver is slightly smaller than a name brand Reese, Draw Tite or Curt. So that adds some sloppy movement. The L shaped part and the part that the ball mounts to has some slop or some clearance, so that adds more sloppy movement.
Don't get me wrong it's not as bad as it sounds. 80% of the time it's fine

Again, I'm willing to bet the part of the OP's problem is the adjustable draw bar.

 

[bigdee]

Re: car shaking when towing pwc

I think that adjustable drawbar is part of your problem. 16? long and a 6? rise on a 1-1/4 receiver is going to create a lot of play. Can you substitute a Drawtite 36078 with a 8? length and 4-3/4? rise? Also your trailer would be better with a slight drop rather than being parallel. Most important....adjust your load so you have 10% of weight on ball.

 

[Philster]

Re: car shaking when towing pwc

I'd check to see that the PWC isn't moving up/down on the trailer. It should be cinched/strapped tightly to the trailer, so that it cannot bounce and is, essentially, one cohesive piece with the trailer.

Up against the winch post tightly, strapped/cinched down in front and in rear. 80% of the time, this is the issue.

 

[Silvertip]

Re: car shaking when towing pwc

And pictures of the setup -- front to back may be worth a thousand more words. Since you feel this when towing, braking becomes more intense and therefore a warped brake rotor can make a pulsing feeling in the car that you might not notice at or as much when not towing. That doesn't account for the feeling when accelerating however. The push-pull feeling is relatively normal but may be more or less noticeable depending on the load, the vehicle and the roads you travel on. If this push-pull feeling is evident at very low speeds (say less than 10 mph) then you really need to look for loose wheels, bearings going bad, suspension issues, loose parts in the hitch trailer frame.