Loud clunking when going into gear

[Thompson1987]

I have a 1986 Thompson Daytona with a Mercruiser 350, SE106 upper and lower unit. Replaced the entire water pump assembly (housing, impeller, gaskets, etc). I am mechanically inclined, but I will admit this was my first time replacing a water pump on a lower unit. Replaced the water pump with relative ease, just taking time to put everything back together the exact same way I took it apart. With a little bit of persuasion was able to get the lower bolted back to the upper (never took the upper off the boat), tightened the bolts and refilled with gear lube using a pump from the bottom. Started the boat up, put it in gear and heard a louder than normal clunk when the gears engaged. I have ran the boat in gear out of water before and never has the clunk going into gear been this loud. The clunk does go away immediately and I do not hear any type of grinding or anything out of the norm at all while the prop is engaged. Is there anything that I could have done and/or missed while installing the lower to the upper? Any help would be much appreciated, thanks.

[admin]

If you are able to get both forward and reverse, then it is safe to say you got it back together properly. The design of the dog clutch means it will clunk. It will be louder out of the water, and even louder with a stainless steel prop. Also make sure the engine is idling at the proper rpm. If it is too high, it will clunk louder also.

Tech Support

[Thompson1987]

Thanks for the quick reply, hoping to be able to take the boat out tomorrow for its maiden voyage of the year. I have asked a few friends who have experience repairing outdrives and they said the same thing, that it will be quite louder out of water. Mine just seems to be even louder than it used to be, not necessarily a "clunk" but more of a metal on metal gears griding together for a quick second then it goes away. Is that normal? With not taking the upper off the boat I figure there isn't really much to screw up bolting the lower back to it, as long as the splines on the driveshaft line up and slide it in. Which if you do not have the splines lined up it won't bolt in to begin with.

[admin]

One thing I forgot to mention is to shift it quickly into gear. Don't shift slowly into gear as that will cause more wear on the clutch system. It should make a quick clunk if your shifting it properly.

Tech support

[vail426]

If you are shifting out of the water, in my mind that is a no no. Without the resistance of the water it will take longer to engage and will probably grind....