Hi Mgoldman,
I also have a 1710, and it has given a few occasions of the transmission locking up in two gears, I think in 1st and reverse. 2nd and 3rd seem to be OK. I have the model with three (and reverse) on the steering column, and 4 ranges on the floor. 1st and reverse are "shift lever up", 2nd and 3rd are "lever down". Going to take off the 4 range cover and see if only one of the two yokes is not moving far enough. I think the steering column linkage has gotten quite sloppy and may be the problem, not the transmission. Do you have the service manual? I have a pdf copy, it is 21 meg.
Eric O