Sorry, I misspoke....there is an O ring on the shift lever end, and a gasket
on the neutral switch end. You can easily find a 71 series workshop manual online which details everything about the gearbox
, but here is the procedure to change the O ring which is leaking...
- remove the transmission
shift lever by removing the nut and washers holding the lever in place.....be careful of the shift detent ball and spring which will try to escape when you take the lever off.
- remove the two wires on the neutral switch, and then remove the neutral switch from its location in the shift valve end cover. Remove the cover over the end of the shift valve by unscrewing the three bolts holding the cover in place. Under the end cover there is a gasket
and the neutral switch cam plate which will fall out when the cover is removed.
- push the shift valve out of the case by tapping lightly on the threaded end of the valve. The valve will exit toward the neutral safety switch direction...nothing spring loaded will explode.
- Replace the old O ring on the shift valve with a new one, put a little oil
on it and replace the shift valve in the transmission
housing the same way it came out. Note: position the notch in the end of the shift valve toward the lower of the three attachment bolt holes.
- place the neutral switch cam in position with the drive tang positioned in the notch in the end of the shift valve. BE CAREFUL HERE....If the cam gets out of position here it's possible to break the tang off of the cam
- install a new gasket and CAREFULLY position the cover in place and tighten the three mounting bolts. Replace the neutral safety switch and wires....it doesn't matter which wire goes where
- reinstall all the bits and pieces on the lever end of the valve in the reverse order of disassembly, putting a bit of grease on the detent ball & spring. The shift lever should move from forward to reverse with light finger pressure.. If not go back and find out why not.....probably the neutral switch cam got out of position and is jammed.
Hope this helps.