can't get lower housing back in place

[da bear]

WE just took the lower case off our Merc 40 hp 2-stroke (1996 model year) to replace the impeller, and now it won't go back together! Everything appears to be lined up correctly, but it seems like the shaft won't go up far enough to let us bolt the housing back in place on the motor-very frustrating!
Any suggestions? It came apart so easily, too!
Thanks

 

[frozenokie]

Re: can't get lower housing back in place

Don't get discouraged. I have pulled lower unit off four different Mercs and I had to do this each and every time due to the same problem you are having.

The first thing is be absolutely sure that everything is back on the way it came off.

Now - the splines of the shaft will only go into the head one way. What I had to do was hold the lower unit up either by hand or with assistance using a jack or similar. turn the shaft clockwise just a hair and retry meshing it back into the head. If it doesn't go in all the way, to within say a 1/4", then it isn't lined up correctly on the splines. Lower it back down to where you can reach in and turn the shaft again and try again. Keep doing this until it meshes. If you turn the shaft too far in a single attempt, you could pass up the line-up point and you would end up having to do this for quite a while.

Keep in mind not to turn the shaft counter-clockwise or you could get the new water impeller fingers bent backwards and that would destroy it when you start up your motor.

It may tire you a little, but keep trying this and eventually you'll get it to line up as I've had to do this EVERY time i've pulled the lower unit.

Good luck...

 

[da bear]

Re: can't get lower housing back in place

Thanks so much for the quick response-now you've raised a new question:redface:
I am concerned that I have the new impeller blades bent the wrong direction-which direction are they supposed to be slanted to the right (as you are looking down at it while installing) or to the left?
We just got this boat, and have only had it out once-don't want to fry the motor on the second launch!
Thanks again for the help on this
DaBear

 

[frozenokie]

Re: can't get lower housing back in place

To the left which would be turning the shaft clockwise (to the right). It may be worth taking the top impeller housing back off for a moment and check to make sure they are correct. No problem on the advice, I just hate to see someone do the same thing I did and screw up the new impeller like have before.