Upgrading Suspension Components on 2005 Forest River 37SP Toyhauler with 5200-lb Axles


The above trailer has tandom 5200 LB AL-CO axles with #42 spindles. Can I upgrade the drums/hubs to 6000 lb with the appropriate bearings? At the same time, Id be upgrading the springs to PR6 or whatever is a 6000 LB spring and installing a Dexter EZ-link kit. So basically, everything except the axle tube will be upgraded. What is the main difference between a 5200 LB Axle and a 6000 LB axle? The reason for the upgrade is the eyes in the shackle links ripped out on the last trip, see Photo I know I am usually loaded to the GVWR of 13400 LB. I am also noticing the springs are starting to flatten out some.


Expert Reply:

Sometimes a trailer with 5200-lb-rated axles will actually use 6000-lb-rated axles with other components that are not rated as highly. You will need to contact AL-KO to find out whether your current axle actually has the 6000-lbs capacity to allow you to usefully upgrade the other components such as the hubs.

You can change out your hub/drum assemblies as long as you can match the bearing numbers, but note that
the hub/drum assemblies we offer can be used with several axle ratings. For example, Dexter Trailer Hub Assembly # 8-201-9UC3-EZ, which uses inner/outer bearing set 25580/15123 and has a 6-on-5-1/2 wheel bolt pattern, is suitable for use on both 5200-lb and 6000-lb axles and wheels from 16- to 18-1/2-inches. The link provided will allow you to narrow the hub/drum product results using your bearing numbers and wheel bolt pattern.

The Dexter E-Z Flex Heavy Duty Rubber Suspension System you referenced, part # K71-652-00, is suited for tandem 6000-lb axle spacing of 33-inches and includes bolts, shackle links and rubber equalizers.

New double-eye leaf springs should be selected based on eye-to-eye length. The # PR6 you referenced measures 24-7/8 inches from eye center to eye center and is intended for 7000-lb axles. For a 6000-lb axle you can use spring # PR5, which is rated for 6000-lb axles and has an eye-to-eye length of 25-1/4-inches. Your existing springs may indeed have flattened out and become elongated from years of use.

You might want to refer to the linked article on trailer suspensions that provides details on all of the required components.

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expert reply by:
Adam R

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