How to Choose Correct Replacement Trailer Idler Hub

Updated 03/19/2021 | Published 03/17/2021

Question:

I am trying to figure out the differences between a 1000, 1100, 1250 and 1350 hub. If they all are 5x 4.5, 1/2 inch studs, straight spindle with 2 x L44629 bearings, why are they rated diffently? Why does only CE smith rate it at 1350 lb?

asked by: John C

Expert Reply:

Without knowing which specific part number hubs you're speaking of, it's hard to say what the differences are, but I can give some generalities that might help answer your question.

The specific hub you'll need will depend on the diameter of the spindle where the inner and outer bearings ride and the diameter of the spindle where the grease seal rides. The wheel size and axle capacity will also come into play as well.

For instance, the # 8-258-50UC1-EZ hub you'd looked at is rated for a 2.2K axle. It uses a L44649 inner and outer bearing f(1.063 inner diameter) and a 10-60 grease seal with has a 1.987 outer diameter and a 1.5 inner diameter. It has a 5 on 4-1/2 inch wheel bolt pattern and is compatible with 13-15 inch wheels.

1000 lb capacity hubs for a 2K axle will use a straight spindle with either a L44649 or a L44643 inner and outer bearing, the grease seals vary as well.

1100 lb capacity hubs for a 2200 lb axle can also use either a L44649 or a L44643 bearing and the seals can also vary.

1250 lb hubs typically use a L44643 bearing and a 12192TB grease seal.

1350 lb hubs usually use a L44649 bearing and a 12192TB seal.

The actual construction of the hub itself also has a bearing on the weight capacity.

Long story short, in order to choose the correct idler hubs for your application, you'll need to choose a replacement that uses the same inner and outer bearings and grease seal dimensions as the hub you're replacing. If you'd care to reply with the inner and outer bearing numbers used by your current hub, the diameter of the spindle where the grease seal rides and the diameter of your current wheels (the last number in your tire size), I'd be happy to help you choose the proper replacement idler hub for your needs.