How do I work out which replacement hub fits my trailer axle?

Answered by RV Parts Giant · Upland, CA · October 9, 2026

Short answer: A hub is matched by five things: axle rating, bolt pattern, stud size, the bearing races pressed into it, and whether the front is threaded for a screw-in cap. Read the bearing numbers and measure the bolt pattern first; those two narrow it to one or two hubs, and the studs and cap thread settle it.

A hub that looks right can still be wrong in three places: the races inside it, the studs, and the front cap. Here is the order to check them in, using the specs DeeMaxx publishes for its galvanized hubs.

1. Read the bearings, then measure the bolt pattern

The bearing numbers tell you the spindle, and the spindle tells you the axle rating. Count the lugs and measure the pattern to confirm.

Axle	Bolt pattern	Studs	Races (inner / outer)	Bearings (inner / outer)	Seal
3.5K	5 on 4.5"	1/2"-20	L-68111 / L-44610	L-68149 / L-44649	1719DLR
6K	6 on 5.5"	1/2"-20	25520 / 15245	25580 / 15123	2250DLR
7K	8 on 6.5"	1/2"-20	25520 / 14276	25580 / 14125A	2250DLR
8K	8 on 6.5"	9/16"-18 or 5/8"-18	25520 / 02420	25580 / 02475	2250DLR

7K and 8K share a bolt pattern, so on an 8-lug trailer the stud size and outer bearing decide it.

2. Threaded or plain front

DeeMaxx marks this in the part number: T is threaded for a screw-in cap, NT (or no letter) takes a press-in dust cap. A threaded hub needs the matching screw-in cap:

3.5K threaded hubs (HUB-545T-GALV) use a 2-5/16"-11 cap, such as the DeeMaxx aluminum cap in black or gray. DeeMaxx cross-references it to Vortex K71-G01-73 (81143) and 21-261.
6K, 7K and 8K threaded hubs use a 2-7/8"-12 cap, the AT-6-8K-LC Lexan cap with a Viton O-ring, listed for oil bath or grease and cross-referenced to 21-35.

The two threads are not interchangeable, so a 3.5K cap will not go on a 6K to 8K hub.

3. Check the brake side

A hub is only half of a drum or disc wheel end. If your trailer has drum brakes, you need a hub-and-drum assembly, not a bare hub. The galvanized hubs above are bare hubs, which DeeMaxx pairs with its slip-over rotors and caliper brackets for disc brakes; confirm the brake flange before ordering those.

What to send us

The numbers off your old bearings, the lug count and pattern, the stud size and a photo of the hub face. With those we can match the hub, the cap and the seal, and ship from Upland, California.