Rebuild or Repair Lippert Tongue Jack?

I had damaged the original LCI 3,500 lb. tongue jack on my RV (chock slipped, jack tube was bent). I popped over to ebay to buy a new Barker jack (had one in the past and was happy) and I stumbled across a new Lippert Components jack for half the price of the Barker! (cue ominous music) I thought DW would be happy since it was the exact same model as the damaged one so it would match.

I installed the new jack and it worked exactly four times. Gearbox seized as I was running it up after hitching to the truck. I originally thought I had electrical issues so I tried moving it with the manual crank. Nope, seized up tight.

ebay guy (RVSurplusInc) says I need to speak to the manufacturer, Lippert says I need to return it to the dealer. I'm pretty sure I just learned a $140 lesson.

Now I have two dead jacks. Has anyone ever disassembled one these buggers? I'd like to Frankenstein one jack out of the first one (good motor and gearbox) and the second one (good tube).