Determining Axle Weight Capacity in Relation to Bolt Patterns, Brake Size and Bearings

Updated 05/15/2017 | Published 05/13/2017

Products Featured in This Question

Replacement Trailer Hub Bearing - L44643

(2147)

$6.78

Replacement Trailer Hub Bearing - 14125A

(138)

$16.04

Replacement Trailer Hub Bearing - 15123

(2147)

$11.79

Replacement Trailer Hub Bearing - 25580

(2147)

$23.81

Replacement Trailer Hub Bearing - L44649

(2147)

$22.82

Replacement Trailer Hub Bearing - L68149

(2147)

$18.41

Replacement Trailer Hub Bearing - LM67048

(2147)

$14.82

Question:

Two answers end with this statement: "The next step would be to measure bolt pattern on the hub, size of brakes, and bearing part numbers, to narrow down the capacity of your axle." That old adage about assumptions comes to mind. Could you give some rule of thumb to relationship of axle capacity, bolt pattern on the hub, size of brakes... Thanks and BTW your FAQ section is great!

asked by: Tim

Helpful Expert Reply:

There are commonalities between bearing combinations, bolt patterns and brake sizes for certain axle capacities. Starting at the low end, axles with a 2,000 lb capacity can use a 4 or 5 bolt hub with a brake size of 7 inches x 1-1/4 inches using inner and outer bearings # L44643 or # L44649.

Axles with a 3,500 lb capacity can use a 4,5 or 6 bolt hub with a brake size of 10 inches x 2-1/4 inches, with outer bearing # L44649 and inner bearing # L68149.

For axles with a capacity of 4,400 lbs, a 6 bolt hub is needed with a brake size of 10 inches x 2-1/4 inches with bearings # L68149 and # LM67048.

Axles with a 5,200 lb capacity use a 6 bolt hub with a brake size of 12 inches x 2 inches and bearings # LM67048 and # 25580. The only difference between those axles and 6,000 lb capacity axles is that the 6k capacity uses one different bearing, # 15123.

Finally for the recreational towing market, there is the 7,000 lb capacity axle, which uses an 8 bolt hub with 12 inch x 2 inch brakes and bearings # 25580 and # 14125A. This is admittedly a lot of information to take in, so I have linked a help article which contains this information in a chart that you may find useful.