For several years now I've owned an AC 416S, and for years the shuttle has been a headache.
99% of the time its fine, but it needs constant adjustment to be right and it'll slip under big loads.
I use this thing for plowing a garden, it'll only pull the plow in low range, if I shift to high it slips. The final drive belt sometime slips on the front pulley and sometimes the slippage comes from within the shuttle pulley set up, Holding brakes will slip allowing the power to counter rotate the reverse side of the drive a bit. I also have two motorless 410S parts machines, one of which I've robbed of its manual lift lever and shaft for the 416S which came to me sans any lift mechanism.
As a tractor, its a beast, I just need to be able to get all of its power to the ground.
There's no reason why this shouldn't be able to pull a plow in a higher gear, fast enough to roll the soil over into the last furrow. In low this thing bearly crawls.
Third and fourth gear are about useless for all but covering ground fast, it won't even go up a minor grade in fourth without slipping the belt or shuttle.
Now, I do have a straight three speed from a Simplicity 3210, it looks to me like that trans will bolt right in? Even the clutch set up is similar. I can use the shifter from the 3210 or modify the one from the 416S.
Does this sound like a viable swap? I see they did make a 410 with a manual 3 speed, so I'm guessing that its the same trans they used in that model. (All of my parts tractors are also shuttle shift models).
I'm thinking that I'd like the shear simplicity of a straight three speed gear box without all the fiddling around with this shuttle shift mess. If it'll fit, the end result should be a very basic, strong machine.