Can Boat Trailer With Shorelander Hub 4470337 go From 12 Inch to 13 Inch Tires & Wheels

Question:

Hello, My boat trailer has Shorelandr hub part # 4470337. I currently have tire size 5.3x12. I would like to upgrade to size 175/80-13 tires and rims because I do a lot of highway travel. I know I don’t have enough clearance on the current fenders so I was going to get 13” fenders. How do I know if my hub will accept a 13” wheel and if I will have enough clearance on the inside of the tire? I currently have 2” between the inside of the tire and the outside of the trailer frame. Can I upgrade to a bigger hub that will give me more clearance?

asked by: Michael J

Helpful Expert Reply:

Okay, we definitely have a solution for you here, and I'll start with the clearance; with trailer tires you need to have 3" of clearance from the top of the tire to your fender and at least 1" of clearance between the inside of the tire and your trailer's frame rail. For reference, a 5.30-12 tire (when inflated) is 5.6" wide and 21.9" diameter, and a 175/80-13 tire is 7" wide and 24.1" in diameter.

So you can use those measurements (1.4" or a little more than 1-3/8" wider as well as 2.2" or a littler more than 2-3/16" larger in diameter) to determine fit. Your hub is designed for wheels up to 12 inches so you will need different hubs, and to use 13" wheels you can replace your Shorelander 4470337 hub with the following:

- Dexter Trailer Idler Hub Assembly # 8-258-50UC1

- Double Lip Grease Seal # 34823

The Dexter hub does come with the bearings, races, and grease seal, but you need to swap out the seal that comes with it with the # 34823 in order to fit your spindle. You can do this because both seals have the same 1.98 outer diameter.

This hub accepts 13" to 15" wheels, so if you measure and do have the clearance you will want to go with the following tire and wheel:

- Karrier ST175/80R13 Radial Trailer Tire with 13" Galvanized Wheel - 5 on 4-1/2 # AM31994

This has the correct bolt pattern to fit the hub, is a galvanized wheel for corrosion protection which is needed for your boat trailer, and is a radial tire which is exactly what you want for highway use as they run cooler, flex more, and last longer for highway use.

I have added links below to some video reviews for you to check out as well if you'd like to take a look.