'89 Merc Black Max 150 Water Pump Change

[jordy1380]

So, I made an attempt to change the water pump in my merc 150 as it looked super simple and sounded pretty easy from reading the repair manual. Everything went great when I was working on it as it's pretty simple to take off the lower unit. I changed the pump, tightened everything back up and when I tried to put the drive shaft back up into the unit, it wouldn't fully go it!!

I read all the posts about how the splines need to line up from the drive shaft, turning the flywheel to get the splines in place, etc. but it didn't feel like it was pushed up enough, which it wasn't. I took my aqua vu camera and put it on a dowel to find that there was a bearing that had dropped down which was preventing it from going into place. After about an hour or so of moving that bearing around and trying to get it to slide into place, it finally went in place and I jumped for joy!!

Is there any trick to keep that bearing from falling down when you take out the lower unit? I don't want to go through that hassle again when I need to change it again. Honestly, the impeller looked good when I took it out and it's been 3 years since it's been changed so I think I'm going to wait at least that long to do it again since it was such a pain.

 

[racerone]

I think you need to investigate this " loose bearing "-----I would not run that motor !

 

[jordy1380]

I think you need to investigate this " loose bearing "-----I would not run that motor !

I've read through a lot of posts where people have issues putting the lower units back in and I've read this on a couple occasions. In the repair manual, there could be some "shim material" then the bearing, then the gear that the drive shaft slides into. When I bought it I was told that the whole motor was 'rebuilt' 5 years ago so that would be 8 years ago from now. Maybe there should have been something shimming the bearing tight but there hasn't been?

Also, I've read a few responses on another forum called hull truth where there's acruelly a tool that mechanics use in case this happened so it may be a common issue? Not sure on this one.

 

[Dukedog]

its a "seal" tha presses inta tha bottom of tha crank... several ways to get it back inta place but it won't stay... power head has ta be pulled and seal replaced with a new one.. its called "carrier assembly".. why, i don't know?... part no. 54196A 6

 

[jordy1380]

its a "seal" tha presses inta tha bottom of tha crank... several ways to get it back inta place but it won't stay... power head has ta be pulled and seal replaced with a new one.. its called "carrier assembly".. why, i don't know?... part no. 54196A 6

That must be it. What point does it serve? Looks like just a round piece of metal...maybe like a thick washer....

 

[sam am I]

Wondered that myself but, put a new one in just for grins when I was there. The drive shaft needs carrying evidently :facepalm:

 

[Dukedog]

That must be it. What point does it serve? Looks like just a round piece of metal...maybe like a thick washer....

supposed ta keep unwanted junk outta tha spline (crank female, drive shaft male) area......

 

[jordy1380]

Ok, so everything is back together and I'm almost 100% sure it's done correctly. With a new pump and impeller does it take a little bit of time for the water to come out the motor? My motor usually don't start peeing until after it warms up a bit so maybe I didn't give it much time but I put the muffs on and started it up tonight. It made a pretty tight seal with the muffs and water was coming out the exhaust like normal but it wasn't coming out the pee hole after a couple minutes. I've read some places where you should take it to the lake after a new water pump rather than starting it on muffs but I don't feel like I gave it much time to warm up. Any truth to this??

 

[Dukedog]

sounds normal.. stats should open in short order.. startin' on tha hose is fine... jus don't expect same results as when in tha water.... keep a hand on tha heads at tha t-stat/block area.. if tha temp comes up dramatically and no stream shut it off...