So I got a 28 tooth speedometer gear with the long shank but I think the diameter is too small. Am I suppose to change the matching gear in the transmission? It seems to be 1/2" too small or 1/4" per side.
I have the same issue, and although I haven't tackled the issue yet, I've been told you may have to swap over both gears (meaning the one on the inside as well). I swapped a NP242 in for an older NP231, and needed to use the 91 VSS from the NP231 (so I had both electronic and cable). The gears on the original speed sensor from the 242 are larger, and no amount of adjusting has gotten the smaller 91 VSS to mesh. Supposedly I have to open the 231 and take the corresponding gear and swap that over too..
I did a few searches last night and finally understand what to do. The housing is eccentric like a cam lobe.THAT is what I have to clock to bring the smaller gear close to the stock worm gear. Thanks!!!!