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35 Merc Lower Unit Removal

A

abl

Contributing Member
"I wrote a while back seeking

"I wrote a while back seeking advice on how to remove the lower unit on my 1986 35 Merc. I tried tying a come-a-long to the lower unit, nothing. I tried working it off with the nuts using wedges, I deformed the nuts. Tried hanging it up-side-down by the lower unit for about a month, nothing. One suggestion was to run the motor....which I did today, only for a couple of minutes because I didn't get any "tell Tale" flow. I disconnected the tell tale line from the block and still no water.....I put a wire in the hole and still nothing. Then, I took the water intake off and found pieces of the impeller. I don't want to run the motor anymore until I get the impeller replaced.....HELP! Thanks! Spring is coming!!!"
 
"Bandit, I did just that for a

"Bandit, I did just that for about a month, with no progress. I guess I'm hoping someone has another "Trick" they can share with me. I had it hanging by the lower unit."
 
"I beginning to give up hope.

"I beginning to give up hope.
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"NO!!!!!! <[img]"http://www.ma

"NO!!!!!!
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I really wanted this to have a happy ending......I'll hang it again for another month or so. Unless there are any other suggestions out there.
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"Hey was this a salt water eng

"Hey was this a salt water engine??
Anyway, after reading all the posts, which there was a ton of them, seems like everyone has suggested just about everything. I would take it to the dealer, let them spend and hour on it and see if they can get it apart for you. Take it to the ugliest smallest marine tech shop around. They seem to be the best for jobs like that."
 
These were a fresh water engin

These were a fresh water engine. The shafts are carbon steel. There are not many other suggestions that I can give you.
 
"Undo the top end from the mid

"Undo the top end from the mid section, chain to lifting points on the powerhead and hoist up with chain block and tackle that should help to separate drive shaft! Your inner water jacket plate is probably in as much need of attention IE: rust, rubber impeller fragments and corrosion inside it dont get caught out if you put a new impeller in it and all of a sudden it sends water and other muck left inside the cooling system rushing around the water jackets and blocks it. AI recently re did my midsection gaskets between the power head and it was feral inside to say the least a lot of muck and corrosion inside to the point it was closing over the flow holes in the water jackets. FYI"
 
"K Gram, I think your suggesti

"K Gram, I think your suggestion is the best one yet, "take it to the ugliest little marine tec shop around". That will be worth the hours work and cost of the impeller to save my engine. Thanks for all the help."
 
"I remember your problem, sorr

"I remember your problem, sorry nothing worked. I'm next to St. Louis if you are close."
 
"Hi JB, I'm in Rhode Islan

"Hi JB, I'm in Rhode Island, but thanks for asking. And thank you for all the help. I'll let you know how I make out. But with snow in the forecast, it may be a little while."
 
"Okay Guys, here's one for

"Okay Guys, here's one for you. My motor is hanging by the lower unit in my garage because I still cannot get the lower unit to drop. The concensus is that the shaft is "frozen" by rust into the powerhead. My Dad saw it today and said, "how about pouring some Coke down there, that stuff eats anything?". Now I have to admit, I looked at him funny at first, but now I'm wondering.....hmmmmmm? What if? What do you think?
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"Andy I've read through al

"Andy I've read through all the posts from this one and the last one. i noticed JB mentions the shift shaft and the drive shaft, DID i read it right that the front of the lower unit ie: the one that sits closest to the rear of the boat is not pulling apart as far as the other end? i just had my lower unit off my 40hp merc several times and the main drive shaft was fairly rusty like BANDIT states they are only carbon steel. I also had a problem with my shift shaft linkage sticking from the top of the power head down to the lower unit. At the top under the carby is the shift shaft selector i found like a roller or slit pin running through that selector that connects it to the shift shaftand locks the splines. i got a small thin nail punch and tapped it out freeing the shift shaft from top end and hey presto the lower unit dropped down. Once it was out I could easily remove the shift shaft from the lower unit and put it back up through the midsection and re connect it to the selector and replace the pin. Locates in the diagram item no3 19,20 and 21 they are the ones to play with.

<center><table border=1><tr><td>http://www.marineengine.com/discus/icons/mime_pdf.gif""" align=left alt=""application/pdf"">selector shaft diagram
[url=""][b]17.pdf[/b][/url] (37.7 k)</td></tr></table></center>"
 
"HI Brent,
I think you may ha

"HI Brent,
I think you may have something there.....I'm going to take another look at things and I'll let you know. It does seem like it's something like you said, and now that I think about it more, the unit only drops less than a quarter of an inch, which would be about the clearance of the shift lever to the motor housing....I'll let you know and thanks for giving me more hope."
 
"Brent,
I think you're r

"Brent,
I think you're right about the pin in the shift shaft lever.....but I can't figure out how to get it out.....I've been able to move the shift lever to a position where I can insert a steel rod into the hole to push the spring pin out but it will only push out about half way because the engine block is in the way.....now I cannot move or twist the shift lever because the pin hits the engine block. Do I have to drill it out?
Here is a photo.

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"It didn't work! I cut th

"It didn't work! I cut the pin off per JB's suggestion on this separate post....http://www.marineengine.com/discus/messages/12479/147330.shtml I confused it with your post then tried to go back....anyway....
I don't believe the shift lever connects to the lower unit the way we thought, JB was right. I'm on my last days of hope on this....the outboard shop may have to figure this one out.
Thanks for trying though. I think the reason the back end opened more was just a leverage issue.
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"I believe it does connect the

"I believe it does connect the way we thought!It was a very, very good suggestion but it obvious it is stuck in the crank."
 
"Have you tried jarring the sh

"Have you tried jarring the shaft? Put some even pressure between the edges of the lower section IE: wood preferably (2 man Job) Get some one to get a block of wood and a mallot and strike the top of the flywheel whilst the other person places even downwards pressure on the lower unit.

By jarring it it will send a shock wave down the drive shaft and help to free up the problem hopefully. Just make sure the items you use to help prise the lower end are wood and same with the block you use to hit with the mallot. I got this info from a boat mechanic who has used this technique on many occassions with rusted sticky drive shafts. Make sure the engine is supportd well ie: on the back of the transom, as I recall you had it hanging upside doen in the garage.. Hope this is of some help??"
 
"Thanks Brent, I'll give i

"Thanks Brent, I'll give it another try once my order for Kroil comes in....I'll soak it for a few days then try your techniques. I don't believe I've tried hiting the top of the fly wheel yet. I've tried hitting everything else with a rubber mallet while there was pressure on the lower unit with wedges....we'll see. Thanks again."
 
"I think it's a sign, just

"I think it's a sign, just as I posted above, the Kroil arrived......wish me luck!"
 
Be sure to use a block of wood

Be sure to use a block of wood as a rubber mallot will absorb all the shock where as the wood will carry the shock through the metal. if u use a rubber mallot only to hit the metal the mallot itself will absorb the shock. Plus the wood is still softer than the metal so the worst u can do is break the wood. Freferably get a piece of wood that fits in the area over the flywheel bolts. you need to keep it as central as possible when you strike it. good luck
 
"Hi Brent,

Here's where

"Hi Brent,

Here's where it stands at this point: I hooked the engine over the end of my work bench via the transom bracket. I have a strap wrapped around the lower unit, I attached a come-along to the strap and rigged it around the other end of the bench with a little piece of wood to keep the engine/drive shaft and cable in alignment. To strike the flywheel, I actually attached a gear puller and I hit the end with a 4lb hammer, just lightly at first but I can put some pretty good wacks on it....I also drilled a small hole in the upper housing of the leg where I can spray Kroil onto the shaft so it will roll to the splines.....(I can put a screw in the hole later if I need to). I also shimmed under the two bolts on either side of the lower unit to aid in the "pressure". I'm hoping I hear a "pop" while I'm sitting on my couch.....we'll see. If I get a chance, I'll take a photo of the setup.....it looks a little crazy, I'm hoping it will eventually work."
 
"Would love to see the pics of

"Would love to see the pics of this contraption. Hey if it works you could patent it make a quick million and then buy a new 300hp Mercury Verado V6 and as for the 35hp? well um, they do make good anchors!!"
 
"Andy..
If it doesnt pop, you

"Andy..
If it doesnt pop, you may consider cutting off the lower unit with a hacksaw.. Start cutting from the front.. you will go through the shift shaft, waterpump, 2 studs and then the driveshaft. These lower units are pretty cheap and plentiful... Make sure you use quality blades. Once lower unit is off, remove the powerhead, weld a plate on the driveshaft and hammer away.. it will come off..."
 
"I'll try to post a photo

"I'll try to post a photo of it tonight! It's not pretty. Thanks for all the advice but if this doesn't work, I'm going to drop it off at a repair shop to see if they can work some magic."
 
"Here is an image of the contr

"Here is an image of the contraption I have set up in my basement trying to remove the lower unit. Any suggestions are welcome.

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"the engine needs to stand on

"the engine needs to stand on its head or hang to let the oil flow down the shaft and into the crank. Don't smack the crankshaft with a hammer, the tappered bearing on top is quite expensive. Looks like a nice rig."
 
"I've got a gear puller at

"I've got a gear puller attached to the flywheel and I've been hitting that! But I've since found another method which I am trying.....since the forward section doesn't separate as much as the aft section, I am going to try and shim it up tight around the center of the lower unit and use the nuts on the aft half of the lower unit to try and "walk" out the shaft.....I started doing it last night and it looked like it might be working but ran out of time....I'll try again tonight and see."
 
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