1982 merc 150 waterpump change: shift issue

[fishingdan]

I have replaced a number waterpumps in various mercury engines over the years (8 or 10???). The latest was in a used 1982 Merc 150 that I picked up last fall. As the procedure dictates, I put the engine in gear and changed out the pump. <br /><br />After reassembling the leg, the lower unit will not go into gear. I plan to take it apart again tomorrow for analysis, but any thoughts on what could have happened? I have not had this issue in the past.<br /><br />I am also only getting a trickle out of the telltale. Plenty of water is pumping out of the prop exhaust when running and the temps seem normal. I suspect the telltale line has some blockage.

 

[phatmanmike]

Re: 1982 merc 150 waterpump change: shift issue

ive done this with my 200 merc.<br /><br />did you slide the lig on REAL slow and make sure the shift shaft was lined up?

 

[fishingdan]

Re: 1982 merc 150 waterpump change: shift issue

I thought I did, but I'm guessing something is off. I will pull the lower unit and see what the scoop is.<br /><br />Thanks

 

[fishingdan]

Re: 1982 merc 150 waterpump change: shift issue

I opened her up again tonight and found what was wrong. The speedometer tubing was wrapped (once) around the shift rod and the shift rod never connected with the lower unit. <br /><br />As far as I can tell, the lower unit is currently in neutral. I know the normal waterpump replacement procedure calls for one to put the engine in gear before dropping the lower unit. I did this at the time. In theory, my lower unit should still be in forward gear, but something turned during the assembly and it shifted into neutral. <br /><br />Two questions:<br />1) What position (f-n-r) should the shifter and the lower unit be in when I reassemble the leg?<br /><br />2) How do I make sure that the shift rod and the lower unit get connected? The shift rod from the engine can move a little bit as you tilt the engine and I can see how one can easily miss the connection. As I lift the lower unit, there doesn't appear to be enough space to align the shift rod while raising the lower unit. Is there some magic that I can use?? I am thinking I need something thin knife blade?<br /><br />Thanks

 

[Texasmark]

Re: 1982 merc 150 waterpump change: shift issue

I have done both. I like N because I think the remote shift linkage and the lower unit can both be set to N more accurately to insure that you have the full FNR range when you are finished. Problem is that you can't turn the driveshaft to get the splines to line up...............But you can if you wrap a piece of small rope (line) one or two turns around the shaft and pull on it enough to get them to line up. In N the shaft turns fairly easily (water pump impeller resistance).<br /><br />You could pack it with vaseline or a piece of bread to hold it in place or use the blade as you mention. Never did the packing...just came to mind, but it ought to work and flush out readily when you run the engine.<br /><br />Mark

 

[fishingdan]

Re: 1982 merc 150 waterpump change: shift issue

Thanks Texasmark, but you lost me. I normally turn the flywheel a bit to get the drive shaft splines to line up. I don't think I have never had to turn the driveshaft itself.

 

[thehermit]

Re: 1982 merc 150 waterpump change: shift issue

DAN, I have had this problem too. You must make sure lower unit is in gear while trying to install. The LU and motor should bothe be in forward. When I did my first gearcase removal on this engine the boof said put it in forward gear. What id didnt tell me was that the gearcase slips out of gear while you are working on itcausing this very puzzling problem. Basically double check that the lower unit is in forward...engine is in forward...and splines meet (along with everything else)...good luck

 

[BF]

Re: 1982 merc 150 waterpump change: shift issue

Like texasmark, I usually leave mine in N. I don't monkey with the shift linkage with the lower unit off, but it's not difficult to find the center of the N position anyway.<br /><br />Ditto on slowing moving the flywheel to get the splines to line up. An extra person is really helpful.. they hold the LU, then you can do the flywheel, then use needle nose plyiers to giggle the shift linkage connection to get the splines aligned.

 

[fishingdan]

Re: 1982 merc 150 waterpump change: shift issue

Thanks folks. As you mentioned hermit, I did it by the book only to find later that something moved. With the LU off, how do I know which way and how far to move the LU shift rod to get it into FWD? <br /><br />I hope I only need to do this once more, but my gut is telling me that the gear position of the LU will be a learning experience.

 

[thehermit]

Re: 1982 merc 150 waterpump change: shift issue

Dan, Carefully twist the shift shaft on the lower unit to one direction. The prop should only move in one direction. Check the book but I believe in forward the prop will not move in a counterclockwise direction (please double check). After you get the lower unit and the linkage in tune put it together.Before you clamp it all down tight check (using the controls) how the prop spins in nuetral/forward/and reverse. <br />TH<br />Takes 5 min to remove and 20 to get back on

 

[fishingdan]

Re: 1982 merc 150 waterpump change: shift issue

Thanks TH.

 

[Texasmark]

Re: 1982 merc 150 waterpump change: shift issue

Yes on the CCW rotation hermit to get the shafts to align; CW and the slip clutch slips. <br />---------<br />I don't use the flywheel cause I usually work alone and I'm busy with the other end, but, as you know, that works too.<br /><br />Mark

 

[fishingdan]

Re: 1982 merc 150 waterpump change: shift issue

I usually work alone on this stuff as well. I never thought of using the prop to turn the driveshaft. That is a heck of a lot easier than trying to work on two ends of a engine at the same time. <br /><br />Last night, I had another failed attempt. Here is what I think it occuring. As I raise the lower unit, the speedo tubing is bending and pushing the shift rod to the side. Today, I will try to secure the speedo tubing before the next attempt.