Help - Lower Unit Won't Come Off

[richb]

I'm trying to inspect the impeller and cannot seem to figure out how the lower unit comes off. I took the 5 nuts off that I could see (2 on each underside and 1 up under by the trim tab). The front of the lower unit drops down about a half inch but the area by the trim tab does not want to drop away even a little. I've tried pounding on it with a rubber mallet but it won't budge on that end. Am I missing something here or what? <br /><br />Mucho Gracias

 

[richb]

Re: Help - Lower Unit Won't Come Off

Sorry but I forgot to say it's a 1988 Merc 100 Horse Outboard.<br /><br />Thanks!

 

[Capt Ron]

Re: Help - Lower Unit Won't Come Off

I might as well be the first to ask, what motor are you working on?<br /><br />Capt Ron

 

[Capt Ron]

Re: Help - Lower Unit Won't Come Off

You beat my question by 1 minute. Sounds like you have removed all of the nuts and bolt but on badly corroded units the water tubes and or drive shaft may be frozen in the gear housing. Pry it off carefully.<br /><br />Good Luck<br />Capt Ron

 

[Capt Ron]

Re: Help - Lower Unit Won't Come Off

You beat my question by 1 minute. Sounds like you have removed all of the nuts and bolt but on badly corroded units the water tubes and or drive shaft may be frozen in the gear housing. Pry it off carefully.<br /><br />Good Luck<br />Capt Ron

 

[richb]

Re: Help - Lower Unit Won't Come Off

Ok Capt Ron I'll keep trying. That might be a good hypothosis. I have no clue as to when the lower unit was last (or ever) dropped on this thing. Right now I'm taking a break cause I was getting a little irritated. I see you mentioned 1 bolt, all I could find was 5 studs, in which I removed the nuts from. Am I missing a bolt somewhere?

 

[JB]

Re: Help - Lower Unit Won't Come Off

Yo, Rich. Did you . .um. .disconnect the shift rod? Just a thought.<br />Good luck.<br />JB

 

[richb]

Re: Help - Lower Unit Won't Come Off

JB,<br /><br />No I didn't. I looked at the linkage around the base of the engine cover but didn't see how it disconnects so as the entire rod could drop out with the lower unit. That and the fact that it's the opposite end of the lower unit that won't break free and drop down made me think it wasn't shift rod related.<br /><br />I am new to outboards and just ordered a service manual today but I was trying to get a jump on the impeller inspection/replacement thing since I am using the boat right now. <br /><br />Any further guidance would be GREATLY APPRECIATED.

 

[ODDD1]

Re: Help - Lower Unit Won't Come Off

Rich, you got all the fasteners.....shift shaft an driveshaft,water tube all slide apart....you are probably stuck on the aft locating pin....get a wedge inthe crack [screwdriver] and strike above trim tab with a mallet.

 

[richb]

Re: Help - Lower Unit Won't Come Off

Thanks guys, it was corroded around the locating pin, I hit it with wd-40 and slowly pryed it down and off.<br /><br />1 more question for you gurus: Are impellers directional? i.e. does it matter with direction the fins are pointing when you drop a new one in?<br /><br />Thanks again!

 

[Capt Ron]

Re: Help - Lower Unit Won't Come Off

The curl of the blades should be positioned in a counterclockwise position when viewed from the top. This means that the drive shaft has to be rotated clockwise while installing pump housing over the impeller. We used to use a little bit of dish soap to make it slide easier. If the impeller is installed backwards it will self destruct on the first startup.<br /><br />Good Luck,<br />Capt Ron

 

[richb]

Re: Help - Lower Unit Won't Come Off

Thank you very much. I understand that if I'm standing in front on the engine looking back toward the prop, and down at the impeller, the blades should be curled counterclock wise. So, use dish soap instead of vaseline huh. <br /><br />You guys have been a terriffic hep.....I'm learning!

 

[Capt Ron]

Re: Help - Lower Unit Won't Come Off

Just to make sure that we understand, The drive shaft rotates clockwise looking from the top. This drags the impeller blades behind the hub which bends them to the left or counterclockwise, again looking from the top. Don't use vasoline, people tend to put gobs of it on and then it plugs up the pump. Dish soap is washed away when you put water to the system and start the motor. Don't need a lot, just enough to ease the impeller into the housing while rotating the shaft.<br /><br />Good Luck,<br /><br />Capt Ron

 

[richb]

Re: Help - Lower Unit Won't Come Off

Just wanted to thank everyone for the help. I went down and got a new impeller yesterday. The guy was showing the how the date of the impeller is cast into them. The one that came out of my boat was dated 1987! Man, is that unreal or what.<br /><br />Anyway I have a new one to plop in. Once again, thanks for the help.