Does the Center Pilot Hole on a Trailer Wheel Have to Be an Exact Size to Fit Over the Hub

Updated 01/23/2014 | Published 01/21/2014

Question:

I currently have an old Dilly boat trailer that has 5.30-12 tires on it. The original rims are 4inch x 4 lug rims. They have a pilot hole that is exactly 2.5 inches across. This pilot hole fits just right around the hub with no visible gap when the wheel is installed. I have been looking on various web sites and it seems that 99 of all new model 5.30-12 tire/rim combinations show a pilot hole of 2 3/4 or 2.8 inches. This would give me a gap from the pilot hole edge on the wheel to axle hub of 1/8 of an inch all the way around. Only the 10 inch models are consistently showing a pilot hole of 2.5. The only exception I found was one galvanized rim without the tire which was for 5.30-12 tires and it had a 2.5 inch pilot hole. My questions are: 1 How important is the pilot hole size? 2 Does it need to be the same as the hub like my current wheels are? 3 Can the pilot hole be slightly bigger then the hub leaving a 1/8 inch gap between them?

asked by: James B

Expert Reply:

There are 2 different types of wheels you will find on a trailer: lug-centric and hub-centric. If your wheels attach to the hub using lug nuts then it is lug-centric. This means that the wheel centers on the hub using the lug nuts.

If your wheels attach to the hub with wheel bolts and no lug nuts then it is hub-centric and the wheel centers on the hub using the center pilot hole.

If you have the first type, lug-centric, then the pilot hole can be larger since it centers on the hub using the lug nuts. If you have the second type, hub-centric, then the pilot hole as to be exact, for you 2-1/2 inches.

I have included a link to all of the tire and wheel combos with 5.30-12 tires and 4 on 4 bolt patterns. I have also included a link to our info-article on trailer tires for you.

expert reply by: Michael H