Tranny issue / eratic speedo

[167XRK]

I am in the process of redoing a 1991 W-250 4x4. yesterday afternoon the speedo went nuts and the tranny started to shift funny... overdrive in and out and harder shifts. Could this be a problem with the (VSS) vehicle speed sensor? I think it is located on the transfer case? Any help would be great

Thanks

 

[1STGENFARMBOY]

Yes thats exactly what the problem is sounds like to me, your spedo will jump all over the place and at the same time it drops out of overdrive,you can pick up a new one at federated auto parts or napa, and yes its on the transfer case, there are two wires on it and it screws on a little gear box.