Double towing and boat sway

dsunday

Recruit
Joined
Feb 9, 2009
Messages
2
I double tow a 27' fifth wheel with my '99 crownline 180 ( 18' ) open bow boat w/V-6 power behind it. The boat trailer is little twitchy when towing behind the fifth wheel, it is steady as a rock when behind the truck by itself. The boat trailer has surge brakes and new tires. The trailer has never swayed so much as to be a danger, but I am concerned of the possibilities. The max speed I tow is 60 mph. Any ideas on things to try to help steady the boat trailer?
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Double towing and boat sway

Trailer sway is usually a sign of imperfect balance.

Do you have 10% of the trailer weight on the hitch ball?
 

dave11

Lieutenant Junior Grade
Joined
Dec 2, 2007
Messages
1,195
Re: Double towing and boat sway

Don't look in your mirrors.
 

Bass Tracker TX17

Petty Officer 1st Class
Joined
May 26, 2008
Messages
253
Re: Double towing and boat sway

sure it's the boat thats the problem and not the 5th wheels rear end actually moving side to side???? The boat sway could be the result and not the cause.
 

dsunday

Recruit
Joined
Feb 9, 2009
Messages
2
Re: Double towing and boat sway

Bass tracker-I have tried to watch the 5th wheel to see, like you said, if it is the cause. But it is hard to concentrate on watching the 5th wheel and boat and keep an eye on the road ahead. I thought that it may be the problem but it seems the boat sways independantly of the 5th wheel.

MTHIEME-With the surge brakes, can I add sway bars or will that cancel the braking action?

JB- I haven't weighed the tongue but it seems plenty heavy. I will put a scale under it in the next couple of days.

Dave11- Your idea is by far the easiest and cheapest. My wife said something similar, but the only thing she uses the mirrors for is applying make-up.
 

mthieme

Captain
Joined
Oct 6, 2007
Messages
3,270
Re: Double towing and boat sway

Most are not recommended for use with surge brakes.
However, there are a few that do.
The fifth wheel could be a deal breaker though. The ones I've seen where for Reese receivers.
 

dave11

Lieutenant Junior Grade
Joined
Dec 2, 2007
Messages
1,195
Re: Double towing and boat sway

dsunday

I have driven doubles, double 40s, and triple trailers. When people ask how you keep the rear trailers from swaying, the old joke is to tell them "I don't look in the mirrors".
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Double towing and boat sway

which is heavier, the camper of the boat. heavier should be in the lead. but with a 5th wheel you do not have that option.
 

willieboy

Seaman
Joined
Jan 28, 2009
Messages
71
Re: Double towing and boat sway

I am guessing you have unloaded enough pin weight on the Fiver and the Fiver is swaying just a touch. Unfortunately, that sway will be amplified with the boat trailer. Sway bars on the boat trailer may help a bit, but the problem is the Fiver I am almost positive. Try this, load all the weight in the Fiver over the pin, give it a test tow and see how it does.
 

cbavier

Lieutenant
Joined
Apr 8, 2007
Messages
1,363
Re: Double towing and boat sway

I tow a 35ft Fith Wheel and I can gaurantee you it's the Fifth Wheel thats causing the boat to sway. I've towed 40 years and a Fifth Wheel sways in the rear. Length of the Fifth Wheel doesn't matter. Even Travel trailers sway. The boat certainly doesn't help but it's not the boat causing the sway.
 

jeeperman

Lieutenant Commander
Joined
Aug 2, 2001
Messages
1,513
Re: Double towing and boat sway

it could be that the tongue weight is just good enough to tow without sway when on the truck. But when on the fith wheel, the air coming off behind is making the boat trailer tongue lift just enough.

But I agree it is more likely the fifth wheel trailer. Just look at the difference in the rear wheel to draw bar distance on your truck compared to the axle to drawbar distance on the fifthwheel trailer.
Your trucks tail is like a Bulldogs and the fiver is like a Whippets (note the pun, lol).
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Double towing and boat sway

just a thought, could the added weight of the boat tongue, on the 5th wheel trailer be throwing the 5th wheels balance of, causing the sway. may lighten up the boat tongue weight. just a thought.
 

Al Bee

Cadet
Joined
Feb 16, 2009
Messages
29
Re: Double towing and boat sway

Does anyone know if adding shocks to the 5th wheel will aid in stabilizing the trailer for double towing, or towing in general?
 
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