1996 Mercury 60 HP BigFoot Clunking in Reverse

[HAHPontoon]

I have a 1996 Mercury 60 hp Big Foot 2 stroke. The boat had sat for 3 years unused (broken dam on lake), so I put a new water pump impeller into it before starting it for the year to put it in the water. On the first attempt to install the lower unit, I had the unit in drive and the shift shaft had wiggled past drive and therefore it would not shift at the console.

I dropped the unit down again and moved the shift shaft into all three positions to make sure it would shift. I installed it in reverse (which I have since read is a no no).

The unit then seemed to shift fine. I started up the boat in neutral. It shifts into drive just fine and back into neutral. I put it in reverse and the unit clunks like its not in gear correctly.

I dropped the lower unit down again and reinstalled in neutral this time (by rotating the flywheel). It still clunks in reverse when the prop is spinning.

Did I permanently damage the lower unit by installing it in reverse or is this something fixable? So much for watching youtube videos on installing a lower unit.

[boats.net]

If prop is still spinning forward then it will make a very load clunk when put in reverse, when motor is in water prop doesn't keep spinning after you take it out of gear and wont make the noise.

[HAHPontoon]

If prop is still spinning forward then it will make a very load clunk when put in reverse, when motor is in water prop doesn't keep spinning after you take it out of gear and wont make the noise.

The issue isn't when you shift into reverse, its when its in reverse and spinning, you can hear a clunking sound in the lower unit when the prop is spinning (motor running). It almost sound like its not full engaged in reverse.

[boats.net]

Without a load on prop it will make some noise usually noticeable with a heavy ss prop more than with an aluminum prop.
Change lower unit oil and look for metal on magnet of drain screw. A lot of metal would indicate gear or bearing damage.