85 250trx fourtrax transmission bench test

first - some background on the 250trx fourtrax gears order. R, N, SL, 1, 2, 3, 4
- also shaft driven


When the quad was put in SL, it would just click and not move. I tore the tranny apart expecting to find something broken, but all i found was a washer laying in the bottom of the case missing from the top of the countershaft. Everything else looked good with only light wear.

i put all the gears back together and put the case back together and wanted to bench test it by shifting through the gears and watching the output drive rotate. i am having all kinds of issues with this. It feels like the drum is binding sometimes and it is very hard to shift or many times i cannot rotate the gears (they lock up). i am beyond frustrated at this point. i've had it apart and together more times than i can count and cannot figure out what is wrong.

I am certain i have everything together correctly and in order.
1. i took video of every piece coming out and laid each piece in order
2. i have the schematic to match against
3. i can tell by "wear" marks that everything is back correctly

has anyone had experience bench testing a tranny? should it shift through the gears easily (understanding that i have to keep the shaft rotating to line up the dogs)

I have the drum groves lined up to each fork and the forks in the correct order and facing correctly up. Nothing appears bent. the shift drum pin is lined up with the hole on the drum and the drum shifter is back on correctly as well.

Biggest problem is i cannot test it with the case off laying how it sits in the bike or everything will fall out. with the case together, i cannot see half of the gears to see what is going on inside. I was told it really has to be sitting like it sits in the bike or gravity makes it difficult with the forks.

Any insight would be appreciated. I'm desperate at this point.

thanks