Re: Gearbox reassembly on 175 mercury
The typical problem areas:
1. Did you turn the flywheel a bit as you were bolting-up the lower unit? Otherwise the splines won't engage.
2. The other area that usually gets ya is the shifting, you've got to make sure the controls and the lower unit are in the same gear or the shift shaft splines won't engage properly with the upper shift rod. Easiest for the 'novice' to do is to have the gearbox and remote control in Neutral. You may have to turn the lower unit's shift shaft to find Neutral, use a set of pliers/Vice Grips padded with tape, or wrap a rag around the shift shaft splines to protect them.
Note that you turn the shift shaft CCW from Forward, to get to Neutral then further CCW to find Reverse. Spin the driveshaft to confirm you're in Neutral.
3. Sometimes the upper shift rod doesn't line up perfectly with the shift shaft, due to a bit of tension on the shift cable. In that case, the only solution is to undo the control cable from the upper shift arm and "jiggle" the shift arm a bit to get splines engaged. Of course, you'll have to be putting upwards pressure on the lower unit when you do this, so you'll need long arms or an extra set of hands!
Hopefully that does the trick, if not, a couple other things to look at would be engagement of the copper water supply tube into the pump, and exhaust tube sticking.
If you have a the plastic guide sleeve inserted into the pump, this shouldn't be a problem. Sometimes the water tube catches the rubber pump gromment and it won't go in all the way. A thin coating of waterproof grease on the tube helps.
A little grease on the exhaust tube helps it slide easily into the rubber gasket in the lower unit.
Hope that helps, let us know how it turns out...........ed
