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Recommendation For Spring Over Axle Conversion Kit To Use on Trailer With 3,500-Lb Axles


I am considering buying this part to do a spring-over-axle conversion on my trailer. I measured my trailer axles circumference with a tailors tape and got 7 5/8. This works out to a 2.43inch diameter. You have SOA conversions for a 3inch axle and a 2 3/8inch axle. My measurement is about 1/16inch away from 2 3/8. Can I assume that its actually 2 3/8, and that trailer axles dont commonly come in 2 7/16inch diameter? I would think that the difference is due to imprecision in measuring, but I would also hate to do something dumb that would render my trailer unsafe. For perspective, the axles are rated for 3500# each. Thanks!

Expert Reply:

The typical axle diameter for an axle that is rated for 3,500-lbs is 2-3/8 inches. Some can have a 3-1/2 inch diameter, but it is very rare.

I would recommend to use the Dexter Trailer Springs Over-Under Conversion Kit, part # K71-384-00, you have referenced, which is designed for the 3,500-lb axle with the 2-3/8 inch diameter.

The Dexter Trailer Springs Over-Under Conversion Kit, part # K71-385-00, is designed for the 3-inch diameter axle that is used on 6,000-lb and 7,200-lb axles.

I am including a picture that will show how the new parts will be installed on your trailer.

When lifting your trailer you need to keep in mind that the geometry of the trailer will change. You may encounter lower or heavier tongue weight, and/or the trailer may become top heavy, contributing to trailer sway and instability, especially when passing large trucks or in high winds. In these situations, it may require you to go with a weight distribution system with sway control, if you are not already using one. I am including a link to a FAQ page on weight distribution and sway control for you to review.

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