Trailer weight distribution question

[Commander_47]

I have a 24 foot (not including pulpit or swim platform) Cuddy Cabin Cruiser with shower, commode, kitchen center and front cabin, 80 gallon fuel tank, water tank and refuse tank.

Weight of the boat with 1/4 tank of gas, empty water and refuse tanks, some gear aboard is approaching 5,500 lbs. Engine stern drive is a Mercruiser 5.7 Gen one.

Duel axle trailer is close to 1,400

My Chevy can easily tow up to 8,300 lbs with a tongue weight of 770. With the boat on the trailer, the transom is at the very end, with only the swim platform, and stern drive extending past it.

As it is, towing the boat is a white knuckle ride no faster than about 40mph due to weight distribution. The Axles clearly need to be moved back.

While the boat is safely in the water, I would like to rebuild the trailer this summer during dry time. Is there a generic formula to where the axles should start out.

In other words, to get the boat back home, I would like to have a safer drive. Is there a starting point where the axles on the trailer should be in relation to the boat?

 

[tpenfield]

Yes, there is a formula for calculating tongue weight and adjusting it by moving the axles.

This question has come up before. Do you know what your current tongue weight is ? Also you will need to know the distance from the axles to the coupler (ball). If a tandem trailer, we can simplify things by taking the average of the distance (coupler-to-axle).

 

[bruceb58]

Buy a Sherline scale to see what your tongue weight is. With my Cobalt I am around 6300# with not much fuel or stuff in the boat and I have a 600# tongue weight(measured). I use a WDH. Most hitch receivers that come with 1/2T trucks are only rated 5000# total weight and 500# tongue. If you are higher, which you are, you either need a WDH or a different receiver.

 

[Scott Danforth]

What is your tow vehicle?

 

[Earl Cordova]

If your tow vehicle is less than a 3/4 ton truck, sell it and purchase something bigger.

 

[GA_Boater]

If your tow vehicle is less than a 3/4 ton truck, sell it and purchase something bigger.

Why?

 

[Scott Danforth]

I have a 24 foot (not including pulpit or swim platform) Cuddy Cabin Cruiser with shower, commode, kitchen center and front cabin, 80 gallon fuel tank, water tank and refuse tank.

Weight of the boat with 1/4 tank of gas, empty water and refuse tanks, some gear aboard is approaching 5,500 lbs. Engine stern drive is a Mercruiser 5.7 Gen one.

Duel axle trailer is close to 1,400

My Chevy can easily tow up to 8,300 lbs with a tongue weight of 770. With the boat on the trailer, the transom is at the very end, with only the swim platform, and stern drive extending past it.

As it is, towing the boat is a white knuckle ride no faster than about 40mph due to weight distribution. The Axles clearly need to be moved back.

While the boat is safely in the water, I would like to rebuild the trailer this summer during dry time. Is there a generic formula to where the axles should start out.

In other words, to get the boat back home, I would like to have a safer drive. Is there a starting point where the axles on the trailer should be in relation to the boat?

Full fuel tank, full water tank, gear and your trailer and you are over your 8300# towing rating

 

[dingbat]

If your tow vehicle is less than a 3/4 ton truck, sell it and purchase something bigger.

Why?

That would be my question as well.
My 1/2 ton is rated to #11,900

 

[tpenfield]

@Commander_47 When you get some figures/measurements for the following . . .

1) current tongue weight and

2) distance from axle(s) to coupler (ball)

Here is my write-up on calculating axle movement to adjust tongue weight (assuming your boat needs to stay where it is on the trailer, and not be adjusted)

http://www.tpenfield.com/Catalina22/Tongue_Wgt.html

 

[Commander_47]

My vehicle is a Chevy Suburban with the tow package and LS v8. It is rated at towing 8300 with a tongue weight of 770.

Dry weight of boat is 5250. I will trailer it with 1/4 tank fuel, no water or refuse in tanks.

If I allow for some gear and a 1400lb trailer, I calculate a max load of 7000, with 11% tongue weight of 759. This should be well within my capabilities.

I will have more data after Tuesday this week. I'll be up at the boat and will take some trailer pictures and a scale for the tongue weight.

It is unsafe to tow at the moment. And I feel it is totally due to trailer axle placement.

I will pull the boat out for it's winter service. At that time the boat/trailer will go in to be dialed in correctly. In the meantime, I need to get it safe enough to move about 50 miles.

 

[bruceb58]

My vehicle is a Chevy Suburban with the tow package and LS v8. It is rated at towing 8300 with a tongue weight of 770.

Dry weight of boat is 5250. I will trailer it with 1/4 tank fuel, no water or refuse in tanks.

If I allow for some gear and a 1400lb trailer, I calculate a max load of 7000, with 11% tongue weight of 759. This should be well within my capabilities.

I will have more data after Tuesday this week. I'll be up at the boat and will take some trailer pictures and a scale for the tongue weight.

It is unsafe to tow at the moment. And I feel it is totally due to trailer axle placement. Sways like a prostitutes butt.

I will pull the boat out for it's winter service. At that time the boat/trailer will go in to be dialed in correctly. In the meantime, I need to get it safe enough to move about 50 miles.

Post a picture of your payload sticker that is inside your driver's door. Seems like you are fine.

 

[tpenfield]

@Commander_47 Don't forget your tape measure and take some measurements of the trailer: coupler -> axles distance.

 

[LundAngler1650]

Can you not slide the winch post and boat a bit more forward?

 

[Commander_47]

Well, it appears I may be SOL with this trailer. From my calculations, the center of the two axles is right at the center of gravity for the boat. Here is what I calculated using tpennfield's formula:

Adjusting the Tongue Weight

www.tpenfield.com

A and C. 225 inches. Distance from tip of trailer to center between axles.

B. There is no B at this time

Tongue weight is only 108 lbs. The trailer is essentially perfectly balanced at both ends. And the vast majority of the weight is behind the rear axle with the boat on it, thereby lifting the tongue off the tow ball when attached.

I see no way to move the axles. That are sprung and permanently in place unless I have the mounts cut off and rewelded.

I am sure this is the original trailer. It was made in 1988. Kind of doesn't make sense. This could never have been right. Unless it somehow got switched in the past.

 

[bruceb58]

I see no way to move the axles. That are sprung and permanently in place unless I have the mounts cut off and rewelded.

And the fenders. Actually not a bad plan because you can still use this trailer. The problem will be figuring out how far to move them.

 

[tpenfield]

My rough calculations are that the CG of the boat is about 5" BEHIND the center point of the 2 axles.

The axles would have to move back about 24" to get you near 10% tongue weight. Something isn't right. Is the boat abnormally stern heavy?

 

[Commander_47]

My rough calculations are that the CG of the boat is about 5" BEHIND the center point of the 2 axles.

The axles would have to move back about 24" to get you near 10% tongue weight. Something isn't right. Is the boat abnormally stern heavy?

I agree totally with your calculations. I am wondering if adding a third axle is a good idea.

That may be easier than them getting the current axles moved. Is that a viable alternative?

 

[icyb]

Ready to fish I'm 6,000 lbs my tongue was 500 lbs. Moved the boat back 4 inches and now my tongue wieght is 400lbs. Tows way better now. I feel you need to determine the tongue wieght. A very light tongue and the trailer will fishtail, too heavy and the truck will scwat at the rear and raise the front end this makes braking difficult. Only you know if it's 800 or 200 pounds on the ball.

 

[PITBoat]

I don't think the main Q was about total weight, but this discussion (and the 1/2 vs 3/4T thing) got me reviewing my rating.

There's nothing about trailering capacity on the door end, but the manual spells it out by model ("ton", and Tahoe or Suburb), 2 or 4WD, Engine, and rear axle ratio.

Mine's 6,500lbs. Interestingly, the 2500 with the same engine and gear ratio is rated at 500lbs less, unless that's an error. Tahoe is rated at 500lbs more (presumably since it weighs less).

You gotta go to the 7.4L (2500 only) to get more capacity (8,500lbs with the 3.73), and a 4.10 rear end for the most (10,000lbs).

I'd imagine the LS motored models will do more, but I have no specs for those.

 

[tpenfield]

I think the main question of this thread was about the ability to increase tongue weight by making a change in the axle position, since the boat position did not have much, if any, room for adjustment.

The OP subsequently indicated that there was 108 lbs of tongue weight without the boat and 'negative' weight with the boat on the trailer. Certainly explains the white-knuckle ride characteristics.

A third axle may provide a solution, but a new trailer may be the better overall solution.