Weight distribution hitched for boat trailers

7Deuce

Active Member
My boat/trailer set up is weighs approximately 7500lbs. The towing capacity of my truck is approximately 9500. I have scaled it several times and although a larger truck would be awesome, it’s just not in the cards right now. The trailer has a bit of sway in the wind and generally is not a real treat to trailer.

I tow several other trailers (RV and cargo) and weight distribution hitches seem to make a significant improvement in sway and overall handling for those trailers. I don’t think I’ve ever seen a boat trailer with a WD hitch. Why is that? Are WD hitches just not appropriate for boat trailers?
 
Generally a boat has a much smaller side profile than a camper trailer of similar weight. If you are getting away it may be a matter of not enough tongue weight. Have you measured the tongue weight?
 
I have one. My boat weights,7200 lbs loaded with trailer and my tow cap is 9400. I used to have issues but put more tongue weight on the truck by sliding the winch upright and mounted a weight dist hitch. Works perfect now. I run about 800-900 lbs tongue weight ( Ihave a special scale to weigh). It’s not uncommon. Burnaby hitch installed it.
 
X2 not enough tongue weight.
 
X2 not enough tongue weight.

Yes, I have scaled the tongue weight and it would benefit from a few hundred more lbs. I plan on moving the boat forward on the trailer about 2-4" to see if that's enough to smarten it up. However, once I do that it would be even more beneficial for the truck to have a WD hitch. I'm still curious why a WD hitch is so common at the campground but so uncommon at the boat ramp :)
 
If you still need more move the axle back.
 
Tongue weight should be about 10-12% of trailer weight.
 
thanks everyone.

I understand the principle of tongue weight and I agree with the comments about it being the most important. I have scaled my truck and I know my tongue weight - it's pretty close to what it should be (~10%) and adding a couple hundred lbs would probably help in general....

However, I'm mostly just wondering why most guys don't use a WD hitch.
 
Most WD hitches don't work with surge brakes. Electric or EOH brakes only. There are a couple of WD hitches that are compatible but they are pricey.
 
Most WD hitches don't work with surge brakes. Electric or EOH brakes only. There are a couple of WD hitches that are compatible but they are pricey.

if memory serves me, surge brakes aren't legal on anything over 2800kg (roughly 6100lbs) so I'm guessing for most larger boats and trailers that would benefit from a WD hitch, they would be EOH anyway.
 
if memory serves me, surge brakes aren't legal on anything over 2800kg (roughly 6100lbs) so I'm guessing for most larger boats and trailers that would benefit from a WD hitch, they would be EOH anyway.

You are correct about the legalities of surge brakes, but have a look on any given day at the boat launch how many people don't know or care about that particular rule.
 
To be frank with you. Boaters would prefer to spend $800 on something other than their trailer. They are generally cheap when it comes to trailer safety. I had one bad experience where I almost lost it. Now I spend on my trailer lots because I run the Island lots and don’t want to ever experience my trailer on the Malahat pushing my SUV side to side. A very frightening experience.
 
My boat/trailer set up is weighs approximately 7500lbs. The towing capacity of my truck is approximately 9500. I have scaled it several times and although a larger truck would be awesome, it’s just not in the cards right now. The trailer has a bit of sway in the wind and generally is not a real treat to trailer.

I tow several other trailers (RV and cargo) and weight distribution hitches seem to make a significant improvement in sway and overall handling for those trailers. I don’t think I’ve ever seen a boat trailer with a WD hitch. Why is that? Are WD hitches just not appropriate for boat trailers?

Hi Deuce I just went through the same process with my boat trailer. I found boat trailer tongue weight for a tandem axle trailer listed as 5-7 % not the standard 10 % for a travel or utility trailer. The info. I got was from a boat trailer manufactures web site. They also have different numbers for single axle boat trailers as well.
The number surprised me as I thought it should be 10% as well .
Boat trailers dont have the A frame style hitch connection they use a reach style frame, so no way to use an equalizer.
I had 725 Lbs on my ball hitch 7000 on the trailer and towed 4800 Km on a week long trip we towed our boat from PEI to Alberta last month.
I found the tandem front axle load much higher that the rear tandem when weighing at a scale.
When I got home I moved the axles forward 8 inches to get 525 tongue weight 7200 trailer .
It tows better than before no sway at all I also found the front tandem tire pressure needed to be 10 psi higher than the rear due to the load.
I used a heat gun to find the front tires were 30 degrees higher in temp. than the rear so I added air to the front 65 55 rear and got the temperatures within 10 degrees .
the infra red heat gun is great to check wheel bearing temperatures, tires, when you stop for fuel .

https://www.shorelandr.com/pages/pf_trstep3.htm
 
Last edited:
https://www.etrailer.com/faq-how-to-determine-trailer-tongue-weight.aspx

Probably good to get a variety of opinions. E trailer says 10-15% tongue weight. It could be in some circumstances less is better. Each case is different. If you have sway however, too little tongue weight is almost always the issue. Like others who’ve posted I’ve been thru this issue twice recently and searched a lot to solve my issue. The last thing to affect sway is your tow vehicle wheel base. If you’ve got a short wheelbase, they are prone to sway. Also, weight distribution hitches are available for boat trailers and they do help.
 
I found the e trailer link as well when I did my research the difference for me was it was not boat trailer specific.
E trailer also suggests trailer tires must be at max inflation pressure at all times (to disregard the actual trailer axle load weight per tire ) or they heat up, so information can be misleading and hard to determine what is right because a lot is opinion based, the trailer manufacturer who built your specific trailer should have spec.s to follow
So do some research based on the info. you get and make your call , wheelbase does make a difference ,so does tow vehicle weight , lengths .
Most not all boat trailers have a single beam reach style frame with a coupler so that may be a factor. If the load distribution hitch is available and helps then it is an option.
I am changing my surge brake actuator to electric to be legal to tow in BC as it is law for trailers over 2800 Kg they must be activated from the cab so surge does not comply.
Im looking at a Carlisle kit electric over hydraulic is around 750 US plus install
 
Last edited:
Another thing if you have s dual axle trailer is your trailer must sit level before and after you are hooked up. All tires and axles must be carrying equal loads. And all tire pressures must be even.
 
I agree on level which is very important for braking, but each axle has a different weight eg. rear tandem axle weight on mine is 2842 lbs. front axle is 4200 lbs. so 65 psi in the rear would and does visibly wear the center of the tire only, so I went to 55 PSI based on weight per tire as it is not equal on all 4 tires. front was 2100 lbs per tire rear was 1420 per tire .

If it weight was equal on all 4 tires you would have 0 tongue weight so the more tongue weight have ,you can expect more weight on the front axle of a tandem trailer , which is why I slid my axles ahead 8 inches which reduced tongue weight from 725 to 525 which is still approx 8% truck rides handles better . I put more load on the rear tires and removed weight from the front now the trailer has 7200 lbs. on it

I based this on my trip from PEI last month approx. 4900 KMs towing 7800 lbs I moved the axle when I got home and t scaled it 3 times to determine the changes to make.
I used a heat gun to verify temperatures which worked well to monitor the truck tires and the trailer tires and bearings, so for me I want even tire wear, no sway and a good balanced level load.
 
Back
Top