Advice needed on dropping lower unit.

[KCLOST]

Re: Advice needed on dropping lower unit.

I still think you should pull the power head!!!!!<br /><br />On an engine that size it's much easier to free the powerhead from the drive shaft compared to removing the lower unit (assuming it's seized together anyway)... You will have the ability to use some side to side pressure, thus freeing the driveshaft from the crank. On a lower unit you can only go in one direction.

 

[michaelbr1]

Re: Advice needed on dropping lower unit.

Another thought that may help. When I pulled one of my powerheads last year, the studs were so corroded in the holes that the thing wouldn't budge. I used a pneumatic impact gun on the end of the studs, and the vibration worked them right out. Not sure how you would get at your drive shaft though.

 

[boatster]

Re: Advice needed on dropping lower unit.

Steve,<br /><br />don't sacrifice the exhaust housing. You can drill a big hole into one of the circular bumper housings and get someone to torch cut the driveshaft. You might also want to check the front bolt at the front of the cavitation plate. It turned out mine was corroded (white rusted) into the exhaust housing. Check to see if that is free or not. If its not free You most likely will need to cut it with a handsaw right between the lower unit and exhaust housing. I would say check that nut first before you do anything. Wedges will definitely not work when that nut is stuck because theres more than 2' of bolt that goes into the exhaust housing and if its stuck, no way in heck your gonna get that out. Good luck. <br /><br />I'm gonna post an update on my progress on my thread

 

[steviecops]

Re: Advice needed on dropping lower unit.

Hi<br />Today I tried to get the powerhead off, but that didn't budge either. I also made sure all the lower unit bolts were free, and they were, so it all still pointed to the drive shaft being stuck solid. Time for action!<br /><br />What I did was enlarged the holes I drilled to get oil onto the shaft, so that they were big enough to get a hacksaw blade in. Then I passed the blade right through the exhaust housing and cut the drive shaft. O.K, so there are now two holes in the exhaust housing, but I can easily repair them with some chemical metal.<br /><br />So the lower unit is off at last. The hard way! Found the impeller hub spun, so an easy repair for the original non pumping problem. The question is now how do I get the drive shaft out of the crankshaft?<br /><br />I put my hand up inside the exhaust housing and tried to wiggle the driveshaft free, but that thing is solid. It isn't moving one millimetre! My manual still hasn't arrived, so I'm at a loss as to how to remove the exhaust housing from the powerhead. I thought that it would just drop off seeing as I have removed the six bolts that hold the powerhead on. Are there any more bolts anywhere?<br /><br />Once I get the drive shaft out, can I have it welded back together? It's a mild steel one.<br /><br />Thanks agin for the advice.<br />Steve

 

[steviecops]

Re: Advice needed on dropping lower unit.

Forgot to mention. When the lower unit came off and I turned the motor back up the right way, about 1 1/2 pints of penetrating oil ran out of the housing! So that things has had a thorough soaking, and still it won't budge!

 

[jim dozier]

Re: Advice needed on dropping lower unit.

You should be able to get the powerhead off now that the lower unit is off. Can you drill a hole throught the driveshaft stuck in the powerhead, insert a bolt, and hammer down on the bolt?

 

[michaelbr1]

Re: Advice needed on dropping lower unit.

If you could take it to a garage where they would have an air hammer, you could probably get it out. The vibration on the end of it would seem to drive it further in but it would actually be busting the seal it has. As I said before, I did this with 4 long studs on my powerhead, and it broke loose instantly.

 

[steviecops]

Re: Advice needed on dropping lower unit.

Jimd<br />I cant get a drill at the drive shaft as I've cut through it about 6 inches up into the exhaust housing.<br /><br />I'll try hammering the shaft up though, that sounds as if it could work.<br /><br />Then I've just got to hope I can get it welded back together again.<br /><br />Thanks for the advice.<br />Steve

 

[KCLOST]

Re: Advice needed on dropping lower unit.

Man that sucks....<br /><br />You diffinitely have a siezed mess....<br /><br />I'm sorry the powerhead removal didn't work for ya... But I guess it's no loss for trying...<br /><br />Keep working at it, you'll get it...

 

[steviecops]

Re: Advice needed on dropping lower unit.

I drove a socket extension bar onto the drive shaft today and pounded the hell out of it with a big hammer, and it still won't move! A great pile of rust fell out of the housing when I tipped the engine up afterwards, but the drive shaft hasn't moved a millimetre!<br /><br />I'll try some more oil now that a lot of the rust has fell away.<br /><br />This motor won't beat me! I'll kill it first!<br />Steve

 

[boatster]

Re: Advice needed on dropping lower unit.

Steve,<br /><br />I just got the driveshaft out of the powerhead by drilling it and breaking it apart with punches. By the apparent stubborness of the rust I don't think you'll have much luck getting it out in your current config. You need to get the exhaust housing off so you can see where the driveshaft meets the powerhead if you want to asses how bad it is. Also I don't think the penetrating oil is going to do anything at this point either. There is supposed to be a rubber sleeve where the shaft meets the powerhead ( I assume it was supposed to keep water out ). At any rate mine was all warped with from the rust expansion that nothing would penetrate into the mating. If anything you'll need to tear away at the now wasted rubber housing to expose the rust binded shaft in the powerhead. Once you get there you'll be able to see how bad it really is. Mine was literally fused. A good 3 hours of drilling, punching and hacking finally got the shaft out in bits and pieces and tons of drill shavings. I hope yours isn't as bad. Luckily for me I found a replacement driveshaft and exhaust housing and I'm going to be using those. Overall the cost to get at this has already exceeded the value of the motor, but I'm goddang too stubborn to give in. Damn sensability, I wanna win this one!!! You seem to be the same. Good luck.<br /><br />Adam<br /><br />BTW in order to get the exhaust housing off all you need to do is remove the six bolts sitting under the powerhead. The housing should slide right off. Oh and also maybe the shift linkage. It should be apparent what else needs to be removed.

 

[steviecops]

Re: Advice needed on dropping lower unit.

Adam<br />Yes, my motor sounds as if it's going to be a difficult as yours was. So far, I've managed to keep the exhaust housing usable, just a couple of holes to fill in later and some paint should see it alright. However, the 6 bolts under the powerhead have been romved and yet the housing hasn't moved! I would have expected to see at least a small gap open up, but it's still tight on there.<br /><br />I'm determined to get it off, even if it's only to see how bad the corrosion at the crank shaft is.<br /><br />Thanks again<br />Steve

 

[steviecops]

Re: Advice needed on dropping lower unit.

I know that you all like to hear of happy endings.<br /><br />Sorry, but no happy ending here! ;o)<br /><br />My Merc 200 is destined for the scrap heap! That drive shaft just wouldn't come out. I couldn't get the power head off in order to drill the drive shaft out, as that was stuck fast too. The closer I got to admitting defeat, the harder I hit the thing, and the bigger hammers I used. I've got to tell you, when those drive shafts decide that they're not coming out, there is no amount of hammering that will get them out! ;o)<br /><br />So I've stripped her bare of all the parts that I thought might be useful, given her a few extra whacks with my biggest hammer and now she sits in my garden awaiting reomoval to the rubbish dump!<br /><br />I hate to admit it, but I know when I'm beaten. Beter luck next time, eh?<br /><br />Thanks for all the advice<br />Steve

 

[boatster]

Re: Advice needed on dropping lower unit.

Steve that is so sad to hear. Now I must ask (like a parasite), any chance you want to sell your scraps? I could always use an extra powerpack, and other junk. I think I'm developing a sick addiction to collecting junked Merc 200's god help me . Oops I forgot you are in the UK.... <br /><br />Heh, I'm kinda like phatmanmike, vulturing in on other's dead motors. He was eyeing my stash had I thrown it in the trash heap. <br /><br />Anyways sorry to hear of your misfortune. Its too bad because that stupid driveshaft is the weak link in an otherwise fabulous motor.

 

[steviecops]

Re: Advice needed on dropping lower unit.

LOL ;o)<br /><br />If you can make it over here boatster, you're welcome to the spares!<br /><br />I'll put this one down to experience and leave the old mercs alone from now on.<br /><br />Thanks<br />Steve