Measuring the Bolt Pattern of a Trailer Hub and is there a 4 on 3 Inch Bolt Pattern

Updated 09/27/2016 | Published 09/26/2016

Question:

I have an older Holsclaw boat trailer with a threaded 4 bolt hub. I measured the distance between the bolts and came up with 3! I was expecting 4inch and seemingly cant find anything with a 3inch pattern. The current tire size is a ST175/80R13.

asked by: Jim

Helpful Expert Reply:

Are you measuring from one bolt to the next or from one across the hub to the opposite one? Because on a 4 on 4 hub if you measure from one to the next you will get about 2.8 inches. But if you measure across it is 4 inches like in the picture I have included.

If you can tell me the inner and outer bearing numbers of the hubs you have I can make some recommendations for new hubs.

expert reply by: Michael H