dexter 10k axle oil change question

If you have metal like you say you're gonna wanna do the races and bearings

 

Change all the seals, flush the hubs to make them really clean, take notice of the amount of metal in them, if there is a lot, check the bearings and replace them all, not one wheel but by axle.

It is far cheaper to replace bearings, seals and oil than to be under a load and having one bearing fail and you are on the side of the road.

 

If you do a halfas job, expect a halfas result.

Don't just attempt to drain and fill, do it right and pull the hub. That will also insure bearing preload is correct. Sometimes doing this right is hard.

 

Looks like to me you’re going to have to tear the hubs down, clean everything up, inspect the bearings, install a new seal, and put it back together.
Otherwise, you’ll never get all the old oil out, and you need to figure out where that grit is coming from. Either somebody poured some dirty oil with grit in there, or something is coming apart inside the hub and causing the grit. Unless it’s poured in, I’ve never seen grit just work its way in from the outside, your seal will leak the oil out before it will let debris in from the outside.

 

The hubs carry oil in their centers, between the bearings. You’ll never get all that out, without disassembly.

With the work you’ve described so far, I would’ve pulled everything, below the frame rails. Obviously, this trailer has been neglected. If you have grit, you need to check it with a magnet. If it sticks, you know you have bearing issues. If it doesn’t, you know you have dirt intrusion, somehow. If the brakes are shot on only one axle, that tells you there’s an issue, either electrical or mechanical. No matter, all four corners need thoroughly gone through and wiring checked for power. I’d pull every bolt out of the suspension and check bushing wear. If the general trailer condition is poor, the bushings will be shot. Lastly, put power to the cord and go through every socket, connector, and inch of wiring. Most likely, there are plenty of chafed wires, corroded connections, etc. This trailer sounds like a fun project, to me.

 

You can do two things. 1st do what every body else is telling you to do or take it to a shop and have them do it for you. Do it right the first time will save you money in the long run.

 

You should use new races too. Don't put a new bearing with an old race