Oil Seal for Dexter 12K Heavy Duty Axle with Disc Brakes

Updated 10/25/2025 | Published 01/02/2019

Question:

Is this what I need for dexter 12k oil bath with disc hubs? Is there a unitized seal available? Thanks

asked by: TJ

Helpful Expert Reply:

Yes, the Oil Seal part # 10-56 is exactly what you need for your Dexter 12K Heavy Duty axle with disc brakes. If you wanted to be absolutely certain you could measure the inner and outer diameter of the one you have now and it should be 3.125" and 4.500" respectively.

expert reply by: Conner L

Gary D.

10/21/2025

I have 12k dually axles that have the black threaded grease caps and inner grease seals. I'm considering ordering the 10-56 oil seals and converting to oil. However, they have disc brakes. I've heard those brakes run hotter and it will melt the rubber in these seals causing them to leak. Is this combination not recommended? Thanks

Jon G.

10/25/2025

@GaryD It's not uncommon to see oil setups on bigger trailers, but I will say while oil tends to run cooler, it's also more prone to issues like what you referenced. I know grease can be a bit more cumbersome, but my vote is to go with grease for peace of mind.