lower unit removal

[newatthis]

I've got a late 80's Mercury Force 9.9 that I'm trying to change the water pump on. What I've read so far tells me I should be able to remove the four lower unit bolts and pull lower unit down and out. Well four bolts out and down only about a half an inch. Is there more? My first outboard, my first boat. Learning as I go. Any help would be super.:%

 

[golfcarmad]

Re: lower unit removal

i have a 7.5 merc.i cant remove lower leg either! however on my model there are 6 bolts at top,and 2 down below,i being under the metal strainer-maybe this helps you.if you ever manager it-let me know please-i'll of course do the same-i am almost at stage of BIG HAMMER

 

[newatthis]

Re: lower unit removal

i have a 7.5 merc.i cant remove lower leg either! however on my model there are 6 bolts at top,and 2 down below,i being under the metal strainer-maybe this helps you.if you ever manager it-let me know please-i'll of course do the same-i am almost at stage of BIG HAMMER

 

[newatthis]

Re: lower unit removal

I found that the shift bar has a number of places that one bar connects to the next. After I dropped the lower unit down about a half inch I could look up inside above lower unit and could see one of those points. An allen wrench later the lower unit came right out. I hope this might help you. Another thing that really helped me out was a vary friendly small shop owner/mechanic that actually took me out back to his shop to show me this.Bonus! He's also the cheapest parts prices I could find anywhere including the inernet. Please let me know how this goes. I could also revisit my local buddy to get some insight on your plight if you would like me to.

 

[holbs]

Re: lower unit removal

I have a 15 hp merc and had the same issue. I had to remove the water pump bolts with an open end wrench one turn at a time but eventually the lower unit came right out but it was a bit time consuming. Its the water pump bolts that were holding her on, there may be a better way but i learned by myself and it worked great.

 

[sport15]

Re: lower unit removal

Watch out for the big hammer!?! I got to that same point on a 'rude 25 when I was a kid and whacked the tar out of the cavitation plate. After breaking a big chunk off it I figured out that the zink tab bolt was the culprit (who's stupid idea was that?). That day I learned two things, one was the value of reading the book and the other was that I was still faster than my Old Man. By the time I got home he'd cooled down enough that I lived to tell about it!

Dave

 

[newatthis]

Re: lower unit removal

Update....new pump in, lower unit on, pumping water as planned. In ref to zink tab bolt. I work on aircraft for the USMC and I do believe the same engineers that design the Harrier do outboards as well. The small experience I have on outboards I find myself asking who the heck plan these things. Definately not mech friendly. I do have new found respect for those who work on these things for a living. The same third arm I grew on the weekends that I use on aircraft I'm using on my outboard. Thanks for the inputs from all!!!!!!!

 

[monk-monk]

Re: lower unit removal

hey newatthis, what a great post!! After reading the first sentence of your apparent hard fought success, I was happy for you but, I have to say what really made my day was the rest of your post...that was my laugh for the day!!! My knee is still red from the slapping it took!! Congrats and thanks. I'm getting ready to do water pump service for the first time...I have my doubts i will be laughing then!!

 

[golfcarmad]

Re: lower unit removal

still cant get lower leg off.Power head came off which surprised me.Does the lower leg (2 parts) just pull apart,I can only get back to drop 1/4 inch-Help?????

 

[emckelvy]

Re: lower unit removal

OK, talking about a 7.5 Merc, right? Well, the Good News is you got the powerhead off, which of course means the driveshaft is not rusted stuck into the crankshaft.

Providing you've loosened/removed the nut at the front of the lower unit up high, and the nut underneath the anti-ventilation plate, about the only thing that typically would prevent the unit from dropping down is salt deposits around the forward-located stud.

Try applying some heat along the area in the "leg" (exhaust tower, center section) where the stud is passing thru. This'll expand the aluminum and hopefully release the stud. A bit of penetrant (such as PB Blaster) after heating will help. It'll also help to carefully pry between the stud and the leg. Use caution not to damage the stud's threads when you're prying on it.

Last resort, you need to 'wedge' the lower unit off. Don't use screwdrivers as the thin blades will break the fragile aluminum!

Use some plastic wood-splitting wedges, or if you can get your hands on some metal, wide-and-thin machinist's wedges, those are the best of all.

Put one in front and one on each side in the rear and carefully tap all of them equally inwards.

I expect you'll find the long stud in front is keeping it from coming down so concentrate your effort on that area.

HTH.........ed