Increase Tire Size?

[ocasioc25]

Hello All,
I am still in the first stages of my build but have been wondering if I could increase my tires from 13" to 15"? The trailer is a Northern Tool, 8 x 5 with a straight axle. I did place the axle over the spring to bring it down a bit. I have some rims I took off my last truck that are 15 x 8 American Racing rims that would look pretty cool. I haven't been able to sell them not even on Craigslist so I might as well use them. That way I have a spare too. If I do sell the rims I can still go to any junkyard and pick up some rims with the same bolt pattern. I believe if I go up in size it will increase the life on the axle bearings but it might mess up something else. What could be the cons effect of this change?

Any help will be appreciated.

Thanks

Carlos

[Woodbutcher]

I have a 5X8 Northern Tool trailer and moved up to 15" tires. I had to use wheel spaces to keep the tires from rubbing on the frame. Nothing else was needed to make it work. Make sure to leave at least an inch between the tire and the frame for suspension travel clearance.

[Kody]

G'day Carlos
If you go up to a 15" rim, the wheels will certainly not revolve as fast as on a 13" rim and the bearings will therefore rotate slower. However, it's not the reduced revs of the wheel that will increase the life of the bearings. The greatest killer for wheel bearings is assembling them too loosely on the axle. Trailer hubs and bearings do not operate under the same conditions as the wheel hubs and bearings as found on your car. They never run as hot as the front wheels because they (mostly) don't have brakes that are working all the time like when you drive to work every day through traffic. The hubs and bearings on your trailer should be set up without any axial play. Tapered roller bearings must have a certain amount of preloading to enable them to operate efficiently and obtain maximum life. How to set the preload can be difficult because too much will destroy the bearings as quick as you can count to 10. Too little and the bearings will fail at the exact moment that can cost you dearly. Check out my post/s on wheel bearings. As already noted, check out the clearance between the tire and the mud guard/fender. A larger tire may hit the fender as the suspension/axle, moves up and down.
Hope this helps,

Kody

[ocasioc25]

Thanks for the help and advice guys. I still haven't installed my fenders yet and I'll make sure they clear amd have enough room around the wheel. I'm going to make my own fenders too. I always pack the bearings and tighten the hub and then back it off just a bit. Not too much that they wobble. On top of that I plan to carry a spare set of bearings just in case.

Thanks

Carlos