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7.5 water pump replacement question

S

Smokinal

New member
I'm helping my buddy replace his water pump in a 7.5 hp Merc thats about 20 yrs old. We got the impeller replaced just fine but in the process, we have messed up the gearing in the lower end somehow. When we put it back together, if the shift lever is in neutral, the lower end is in forward; and if the lever is in reverse, the lower end is in neutral.
We have had this thing apart 7 times. Logic is telling us to take it apart with the lower end in neutral (lever will be in reverse), move the lever to neutral and reinstall. But it either will not go together that way or it still doesn't fix it.
I have tried to manually spin the splined shaft on the lower end when it is out, to find the neutral position but it will only spin to 2 positions: neutral and forward; I cant get it to spin to all 3 positions. Could we have messed up the gearing in the lower end somehow? How do we get this thing back together correctly? Vids on it?
 
This is a very common thing.--------------They jump into forward from nuetral while you are not looking !----------So get forward on the lower unit.---------Put lever in forward and re-assemble.--------Can't count how many times I have done this procedure.
 
Thanks Racer; I'll try it again. I believe, though, that we have tried it that way but the lower end will not slide up into place. It binds up about 1.5 inches from seating position. Almost like the top of the long shaft will not mesh with the engine like that...?
 
As stated I have done this caper many times.-------------YOU need to make sure lower unit and lever are in the same gear.--------Ease the lower unit up into place keeping the surfaces parralel and in line.-----Make sure water tube is in the plastic guide tube.-------Then rotate flywheel slightly if need be to engage the splines.-----Done this countless times with no problems !!
 
Turn the entire motor upside down to reassemble it--the Dave Bernard Method. And look down (now) into the tower to see if the shifter rod is centered in the hole. If not, center it with a Philips screwdriver. The splines go only ONE way, so you MUST get them right. (Not the orphan or blind spline in the shifter splines.)

Finally, IF you didn't yank the shifter shaft out of the lower unit by now consider yourself lucky!

Jeff
Those are tricky little b*st*rds to put back together if you haven't done one before.
 
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