Hello all to this is of interest or who have already done it.
I finally decided to do a manual to electric dolly conversion on my Detro made trailer.
IM 69 years old and no where as spunky as I once was ( sound familiar) anyways I bought a 12 volt motor conversion gear drive kit for my trailer. I have been almost a full day and a half getting all this changed out being I am somewhat handi capped with my legs not in the best of shape.
I was thinking I could have this knocked out in a half day at best.
So my original dolly gears had a solid roll pin that would not budge in the gear to the shaft. I then center punched and drilled to finally get that out to relieve the gear and get the shaft out. Had to finally cut the OEM shaft in 3 pieces with a saws all its been so much fun .
I finally got everything back in line had to put cross shaft in lathe to get enough clearance to get Hex adapter to shaft motor lined up.
So moral of the story is dont believe the plug and play senario the vendor tells you. All things worth while take time or something like that. You all be blessed.

For those of you thinking of making this move DO IT Im so Happy to just making a move with my finger to raise and lower legs its well worth the investment.