170 Transmission Problem

(quoted from post at 16:55:36 06/12/19) My faithful AC 170 failed me yesterday while getting ready to bale hay. While backing in reverse, the tranny made a "thunk" and the tractor stopped moving. I found I could no longer shift into (or out of) any gears. After inspection with the tranny cover removed, I found the forward shift fork (gears 4-6 and 7-8, I believe?) had snapped off and was loose in the tranny. The idler controlled by the shift fork was all the way forward (I'm guessing in gear 7-8?). I hastily tack welded the shift fork to the broken pin as a quick fix and moved all the gears to neutral (I think?). I then re-installed the cover with all three forks in the neutral position. At that point, I could shift gears, but the tractor still won't move, and the engine bogs down when I engage the power director. What's the best way to diagnose this problem, and how can I unlock the tranny if it is indeed stuck in 7-8 and reverse at the same time?

I'm going to assume your broken fork was the longest fork?? That is reverse. I've welded many without any issues. The front fork is 3rd and 4th transmission gears (4-6 and 7-8 speeds). The rear fork is 1st and 2nd transmission gears (1-2 and 3-5 speeds). Anyway, as long as you welded the fork close to where it belongs, you have assembled it back onto the transmission top wrong. You are in two gears at once. The shift cover must be installed when it is in SECOND gear and the tranny has to be in SECOND gear (3-5 speed position). The two shoulder bolts go in the left front and right rear corners of the shift cover to align it to the transmission case.

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