Troubleshooting Trailer Suspension Sag Causing the Equalizers to Pitch Forward

Updated 06/25/2010 | Published 06/24/2010

Question:

I just bought a used boat and noticed that the equalizer between the two axles is always tilted, the end toward the front of the trailer is almost touching the frame, similar on both sides, may be worse on the right side. As far as I know the springs are stock. Is this a weight distribution issue or are the springs shot or ? I didnt see anything broken or loose and it was sitting on a fairly level driveway.

asked by: James H

Expert Reply:

The first thing to check is that the boat is loaded properly on the trailer. If there is significantly more weight on one of the trailer axles you will need to adjust the cargo in the boat or the way the boat is loaded on the trailer to get the proper amount of tongue weight and even out the load over the trailer axles. You will most likely find that the weight of the boat is centered too far forward and that moving cargo or positioning the boat slightly rearward on the trailer will increase the clearance for the front side of your equalizers. Be careful not to reduce the tongue weight of the trailer too much or trailer sway can result.

It could also mean that the bushings for the equalizers are worn and will need to be replaced (though it is often easier and more cost effective to just change the equalizers). It is also possible that the wrong size springs were installed on the boat trailer or that they are worn and need to be replaced.

Another thing to check are the shackles. If one is flipped in the wrong direction, you will need to jack up the trailer and return the shackle to the correct position.

If the trailer is not the correct one for the boat, it could cause the problem. If you determine that none of these are causing the problem or are just unsure, I recommend taking the trailer to a qualified trailer mechanic for further troubleshooting.

I have included a link to an FAQ on trailer suspension below. There is a section on equalizers about a quarter of the way down the page. When replacing equalizers, there are several measurements that should be considered. These are outlined in the FAQ article.

expert reply by: Michael H