# How to determine trailer jack capacity



## Ron19 (Jan 8, 2009)

Bout time for a new one. Current one has no marking that tells me its capacity. I have about 4000 lbs w/ loaded boat and motor. Thanks.


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## Patriot (Jun 4, 2009)

1,000lb minimum. Fulton makes one that folds and has 6" caster wheel. 23" lift and 10" of travel. About $50.00 bucks.

They make a 2,500lb one also, but that's a bit overkill. About $110.00 bucks.

Hope this helps.


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## sealark (Sep 27, 2007)

I would say no more than 500 lbs on the tongue. What you want is when you break the trailer surges forward and causes the back of tow vehicle to be pushed down instead of lifting the rear end. Use a bathroom scale to test for the tongue weight. Just about any of the jacks will work on your boat however the higher capacity and price will outlast the smaller ones.:thumbup:


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## Patriot (Jun 4, 2009)

To Clarify....

Gross tow weight (GTW) equals the weight of the load on the trailer and the trailer weight itself in towing position. 

Tongue weight (TW) calculation includes the GTW AND the cargo weight behind the rear axle in the vehicle. Trailer tongue weight is the downward force exerted on the hitch ball by the trailer coupler. *In most cases, it is about 10 to 15 percent of the GTW.* Too much tongwue weight causes the front suspension of the tow vehicle to lift/unload and can cause dangerous handling condition. Too little tongue weight, and the trailer will start to act on its own and cause a dangerous towing condition like swerving.

Your boat loaded is 4000lb plus the trailer (est 1000lbs) puts you at around 5000lbs GTW.

10-15 percent is 500-750lbs for proper tongue weight. IF you have a bracket and a 4 stroke motor this adds more weight to the moment arm extending aft of the trailer wheels, so that will also need to be taken into consideration..meaning leaning towards a 15 -20 percent figure. 

The 1000lb capacity trailer jack gives you a comfortible safety margin with less tendancy to bend if you are moving the bow of the boat by hand. I prefer using the 2500lb jack, not for the weight capacity, but for the adjustable leg. It has a pin that inserts through the leg tubes that allows you to extend/retract the leg, which takes away a lot of the extra turns on the wench handle. Downside, it does not have the caster wheel and does not fold up.

The 1000lb jack one works fine, but does not have the pin feature like the larger jack, so you will be turning that handle a lot more. 

Hope this helps. Always err to safety. 

If in doubt, take the rig to the boat trailer shop and they can ensure your are set up properly using the proper equipment.


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