Trick to align drive shaft splines to install lower unit.

[byron.akhavi@gmail.com]

I recently went with a friend that had his outboard motor serviced. I witnessed a mechanic use a sharpie to mark the drive shaft and water pump housing. He did in the same manner I mark my trim anode to position it in place upon install. He then turned the drive shaft clockwise to mount the water pump housing onto the impeller. Then he aligned the sharpie marks and installed the lower unit splines without resistance.

I normally have to turn the lower unit to align the splines a bit and then double check for the shift shaft and water tube. He also used a tie down strap to secure the lower unit and slowly bring it up to position the shift shaft and water tube. Used an inspection light and thin nylon trim tool to slide in and move the shift shaft tube in place.

Do you guys use a sharpie to mark the unit when it is removed and then align the marks?? Never heard of this method in any forum and just happened to observe it. It seems like a great method and worked.

[99yam40]

I just play with it for a few seconds to get it back into place

[robert graham]

I just play with it for a few seconds to get it back into place

Me too….why make a lot of work out of it?

[boscoe99]

If it works it works. The marker that is.


I have heard of using a shim type device to help position the upper shift rod into place. Last thing in the world for a mechanic is an irate customer that trailered his boat to the ramp only to find out that the shift rods were not connected.

And when it comes to the F350 and the XF425, the tie down straps are all but an essential tool. If a guy is removing and reinstalling multiple smaller gear cases a day, I can see the strap being used on those as well.

[jrchandler]

I put mine into forward before removing the lower unit. Then you can spin the prop to turn the shaft to align the splines.

[oldmako69]

Seconds or thirds on the ratchet strap. My lower units are heavy and they NEVER slide right back into the proper position without a lot of messing around. No longer strong enough to go through that crap with my old back.

The sharpie trick sounds interesting unless you're putting in a new WP with housing. I like the idea of leaving it in gear. Funny that the manual says N.