John:
I have spent lots of time working on this as I replaced my shifter cables with new Teleflx cables and I replaced the old style shifter with a new single lever one.
What I learned from this regarding not shifting into a gear, fwd or rev, is that you need to look very closely at your transmission lever and the shifter cable mount and clamp hold down. To study this, first, remove the shifter cable from the shifter lever on the transmission. Now, move the trans shifter lever into fwd, neutral rev, just move it back and forth. Now stop it in neutral, making sure your this trans shifter lever is is neutral. Next, with the cable end removed, move your shifter at the helm into fwd, neutral, rev and look at the movement of the cable end, obviously this takes 2 people. Now, position the helm shifter in the neutral position. Look at the cable clamp and the cable feed and it should be 90 degrees to the transmission lever when both are in neutral. What you might find is that this is not the case.. This cable mount, cable clamp, on the transmission, we had to remake so that we could position the cable 90 degrees to the lever in neutral. If this is off then the cable will push more in one direction over the other. This study of the movement of the transmission lever related to the cable being 90 degrees may fix your problem.
That is where I would start.
Hayden
