Measuring Tongue Weight

homeputter · Mar 30, 2012

Since I just bought a 18' trailer, I wanted to load my BX25 and box blade to mark the best location to give optimum hitch weight. I set the BB as far forward as easily possible and parked the tractor right next to it. I rigged up 2 bathroom scales to divide the tongue load and was surprised by the results. I made a table of the hitch height and scale readings. I estimate my payload is about 1900lbs. With the tongue at my ball height, the weight was about 368lb. When I lowered the height I expected the weight to increase, instead it slightly dropped in steps until I lowered it to 13-1/2" where the weight gradually started increasing. It seems lowering it just allowed my load to be picked up more on the front set of wheels and less on the tongue. When I squeezed the BB and the tractor as far forward as possible (still with the bucket flat on the deck) the weight still INCREASED from 13.5" (above the ground) at 518lb to 569lb when the tongue was raised to 15-3/4".

Anyway, the results were surprising to me, I had just assumed that lowering the tongue would increase the hitch weight.

Is 10% of payload weight about right for hitch weight?

triptester · Mar 31, 2012

Normal suggested hitch weight is between 10-15 percent.

Diamondpilot · Mar 31, 2012

Yep, 10% is about right. If its not enough try backing the tractor on the trailer. Its what I do most of the time.

Chris

s219 · Mar 31, 2012

homeputter said:
Since I just bought a 18' trailer, I wanted to load my BX25 and box blade to mark the best location to give optimum hitch weight. I set the BB as far forward as easily possible and parked the tractor right next to it. I rigged up 2 bathroom scales to divide the tongue load and was surprised by the results. I made a table of the hitch height and scale readings. I estimate my payload is about 1900lbs. With the tongue at my ball height, the weight was about 368lb. When I lowered the height I expected the weight to increase, instead it slightly dropped in steps until I lowered it to 13-1/2" where the weight gradually started increasing. It seems lowering it just allowed my load to be picked up more on the front set of wheels and less on the tongue. When I squeezed the BB and the tractor as far forward as possible (still with the bucket flat on the deck) the weight still INCREASED from 13.5" (above the ground) at 518lb to 569lb when the tongue was raised to 15-3/4".

Good to see you measuring this so carefully -- it's good to get it right.

I think your theory is spot on -- if you can get the trailer deck near level, it will help spread load over both axles and both sets of springs, and that ought to relieve the tongue weight a bit. That probably is what was happening when you noticed your "minimum".

jdonovan · Mar 31, 2012

homeputter said:
Is 10% of payload weight about right for hitch weight?

Not quite. The tongue should be 10-15% of total trailer weight... i.e load + empty trailer.

changing hitch height generally does more to adjust axle weight on the trailer... assuming you've got a dual-axle trailer.

If you want to adjust tongue weight you move the center of the load closer to the tongue.

duroc · Apr 2, 2012

Before loading the trailer, it's best to "first" hook up the trailer and take it to a level pad or parking lot. Disconnect the trailer from the tow vehicle and measure each corner of the trailer from the ground up to the top of the trailer bed to ensure that the trailer sits level. Raise or lower the tongue up/down until all the corner measurements match. Once you accomplish that, measure from the ground up to the top of the trailer coupler (where the top of the hitch-ball will come to rest). That will give you the ball height that is needed for the tow vehicle. I think you'll find that it's somewhere between 17" and 18" to the ball top depending on what configuration axle mounting you have.

I might add...you need to use the ball height of the trailer (level) as a starting point and NOT use your existing tow vehicle ball height... unless their height measurements match. Just in case you didn't know that!

jejeosborne · Apr 4, 2012

Everyone has a preference but I set my ball height about 1" higher than the level loaded trailer height. This compensates for the suspension drop on the truck and you end up level again. Each truck is different and it depends if you are using a weight distribution hitch. End result is you want tow vehicle and trailer level when loaded and hitched. Check your hitch rating too. You might need a WD hitch.

Bladehauler · Apr 4, 2012

I might also add , if there is a truck stop, grain elevator or quarry nearby, you can ask them to let you weigh your dropped trailer, ie, pull on the scale, put the tongue jack on one scale pad and the trailer tires on the next one back , then pull your truck to the next pad up or off the scale and get a certified weight for your load. most scales don't mind unless their busy.

C-ya