Re: Lower unit won't reinstall 10HP Chrysler
The lower unit clutch is spring loaded and it is way easier to get it into forward than reverse because of this. The shift rod moves a stepped cam that pushes a ball ended rod pressing on the clutch retaining roll pin and the spring. The largest step is on top for reverse and the smallest is on the bottom for forward. Thus going into forward you are releasing spring pressure and in reverse you are compressing it. Try pushing down on the lower shift lever by hand and see how much force it actually takes! Surprising, isn't it?
Forward is up and reverse is down SO:
Pull the shift rod all the way up and put the engine shift lever in reverse. This extends both rods and gives you room to attach the two shift rods together. Then as you push up the lower unit, put the engine lever in forward. If you leave the engine lever in reverse, frequently, the mechanical advantage of the linkage will prevent you from moving it as you push up the lower unit. It may also be necessary to turn the prop shaft while engaging the gears so the drive dogs will clear each other.
Now: This assumes that all you did when you removed the lower unit was to change the water pump impeller and did not disassemble the lower unit itself. If you did disassemble the lower unit, there is an odd "U" shaped bent pressure spring that holds the cam tightly against the casting. If this is assembled incorrectly it can bind the stepped cam---but that is highly unlikely--not impossible, just unlikely because it sits in a depression in the casting.
Couple of other things: Be certain the cam is installed with the steps facing the rear of the lower unit so it actually moves the rod. Be certain that the drive dog is not jamming on the prop shaft splines and preventing shifting movement. Also make sure that the shift rod is moving smoothly through the seal. An old swollen tight seal can stop all shifting.
