Troubleshooting Difference in Space Between Tires on Tandem Axle Boat Trailer

Updated 05/29/2025 | Published 08/27/2017

Question:

Hello, I have a tandem boat trailer that I replaced both axles on this spring. I now notice that the space between the axles is different from the left to the right side. The difference between the tires is 1 inch wider on the left than on the right. Is there a way to increase or decrease the spacing between the tires on either side to equalize and square them up? Thanks in advance

asked by: MIke

Expert Reply:

There are a variety of reasons why the space between the tires on your tandem axle trailer might differ between the left and right side.

I first recommend verifying that the trailer is on even ground when you are taking the measurements between the wheels. It seems simple, but if the trailer is on unlevel ground, it can cause one side of the suspension to have more load on it, thus leading to the difference in tire spacing you are seeing.

If the unequal spacing on the tires is present on level ground, I recommend checking the suspension system. First take a quick measurement between the spring hangers on both sides of the trailer to make sure they are equal. This will at least rule out that the issue is not caused by where the springs are attached on the trailer.

If everything checks out okay, then it may simply be time to replace the springs on your trailer. They might be unevenly worn, causing one side of the trailer to sag a bit more than the other. If you find this to be the case, I recommend replacing all the springs at once, even if one appears to be in better condition. In general, trailer leaf springs and their components should at least be checked for wear and damage every 12 months and replaced as needed.

I have attached a link that will take you to our available selection of trailer suspension products, along with an article that you might find helpful.

expert reply by: Chris R

Mark

5/29/2025

Hey ya Chris, I'd like to get your thoughts on a similar axle spacing issue before I start purchasing materials and equipment to correct the issue. Below is a copy of a message sent to Keyston. TT: 2018.5 Montana 3120RL Tandem Dexter axle 7k w/ST235/80R16 tires Wet bolt shackles w/LCI Road Armor 12k TT weight Trailer currently sits unloaded, closed (slides in) and leveled with landing gear down on very level RV garage parking Post to Keystone: Tire Gap Recently had 2 leaf springs (rear axle) replaced due to a leaf retaining bolt failure on the passenger side, where the rear axle slipped out of track. Mobile mech replaced both rear leaf springs. I note uneven wear on the rear tires. It appears as though the rear axle is out of alignment (not tracking straight). There is an an approximate inch difference in the gap between the tires with the left side having the greater distance (6.5” vice 5.5”- SWAG = Special Wild Ass Guess) Looking to Keystones for some direction on how I should approach correcting this issue. I have searched to the end of the internet and could not find a suitable answer. Of note prior to the rear right leaf failing, the brake on the same right rear failed causing the tire to drag and need to be replaced. The brake drum and spindle apparently did not suffer any known damage, with further travel from Colorado Springs to Goodyear AZ being uneventful with the exception of tire wear and the difference between tire gap. Thanks in advance