How to determine what axle you have:
Most common utility trailer axles fall into two types, and only three sizes.
The two axle types:
Rubber Ride Torsion (no springs)
Conventional Leaf Spring (either straight or dropped)
The Three Basic Sizes:
| Typical Rating |
Axle tube OD Size (spring axle only) |
Spindle Number (see chart below) |
Outer Bearing ID Size |
Inner Bearing ID Size |
Seal ID Size |
Brake drum Size (Bolt pattern) (See chart below) |
Dust cap ID Size |
| 2000#-2200# |
1.75" |
BT8 or BTR |
1.000" (L44643) 1.063" (L44649) |
Same as Outer Bearing |
1.25" (12192TB) or 1.50" (10-60) |
7" (4x4 or 4x4.5) |
1.78 or 1.98" |
| 3500# |
2.375" |
#84 |
1.063" (L44649) |
1.375"(L68149) |
1.75" (10-19)*** |
10" 5 Lug (4.5"/4.75"/ 5.0"/5.5")+(6x5.5") |
1.98" |
| 5200#-7000# |
3.00" |
#42 |
1.25" (15123) (LD)* 1.25" (14125A) (HD) |
1.75" ( 25580) |
2.125 (10-10)* 2.250 (10-36) |
12" (6x5.5" or 8x6.5") |
2.44" or 2.71" |
As you can see, there are only 3 basic sizes of axles:
With 4, 6 and 8 bolt Wheels, just measure across to the opposite lug to get the bolt circle.
On 5 bolt wheels, you must use the chart below to figure your bolt circle:
How to measure your axle, (to order a replacement)
* Notes:
- There are many other less common axles out there, this covers "Most" axles 7000# and lighter
- Mobile home axles may or may not use standard parts, you have to look inside yourself.
- The large #42 spindle can have either 2.25 or 2.125 ID seals, you have to check.
- 'Not all axles have brakes, but the bearing sizes are still the same, either brake or idler.
- Rarely, I have seen a LM67048 Outer bearing used on the #42 spindle (light duty)
*** on Some Square Tube axles, found almost always on Boat Trailers (EZ Loader, Ranger, etc) Made by UFP, the grease seal will be slightly smaller ID of 1.68". If you have a boat trailer with a square tube axle, check your seal size before ordering.