I disagree with one observation, and agree with the other.??
For our Aliners and all aframe torsion axles that I know of, there are only two inner seal part numbers for our hub/drum assemblies. They are listed in the AOC DIY section under bearings and seals: (https://alinerownersclub.org/diy/wiki-bearings-seals/).? They are industry standard, so any make will fit. If your local Pep Boys doesn't stock them, check with a truck parts jobber. The seal must be replaced whenever the hub/drum assembly is removed from the axle spindle.?
I totally agree that a $300 regrease job is usurous. Learn to do it yourself and save on a job that you'll do better and with more caring than a shop monkey would.?
Dave?
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One tricky part in that job is you're supposed to replace the grease seals.? But the only way to find out the grease seal size is to jack up the trailer and pull the hub.? Then hope that a local auto parts store has that in stock, and you don't have to reassemble dissemble again.
In my area they charge $300 to regrease the hubs.? It's gotten pricey.? But the worst part is they've damaged my trailer 3 times at 3 different shops moving the trailer around their lot.? Nothing major just scuffed paint or a dent in the corner cap, but still aggravating.