SM420 Transmission Inspection

I am just cracking open my SM420 tranny for inspection. From it shifted and spun in all gears when I got it. I have not done this before so what should I be looking for in particular during inspection? What cleaning techniques did yall use? I was just thinking a dunk is carb cleaner. Should I just do a full rebuild (with Novak Kit)? I've never done this kind of work and was wondering if i should just leave this to the professionals.

Thanks

I do have a few rebuild guides but would like to hear from those who have done it.

 

Ahh they are pretty simple to be honest, just take your time, have an exploede diagram and a digital camera handy for step by step disassembly pics for reassembly "which way did that go" type stuff..

 

I saw a pic, somewhere in my search of T18 rebuild stuff, of a rack a guy made to hang all the internals on as he removed them from the case. Pull it out, hang it on the rack the way it came out, install in reverse order. It was just a hunk of heavy c- channel with another piece welded onto it, at one end, at 90*. Then parallel with the bottom piece, a piece of pipe was welded on to hang the parts from.

 

My SM465 had been sitting for a number of years and there was some rust on the mainshaft that could not been seen until I took it apart. It never sat outside but must have goten some moisture in it. Just something to look for when you take it apart.