Lower Unit Won't Budge

[racerone]

I have used hydraulic puller to get the stubborn ones apart.-----Perhaps your local shop has done these before and can help you.

 

[oldboat1]

Whacking on the AV plate is always a little dicey, but I've used a two by four and a mallet, moving side to side -- 2x4 lengthwise along the plate with the wide side against the leg. Hit it downward in the middle, angling a bit inward. If you get a little progress, move to wedges, again side to side.

 

[Ol Sarge]

Whacking on the AV plate is always a little dicey, but I've used a two by four and a mallet, moving side to side -- 2x4 lengthwise along the plate with the wide side against the leg. Hit it downward in the middle, angling a bit inward. If you get a little progress, move to wedges, again side to side.

I'm going to try hanging weights on the lower unit and with all the bolts out running the motor to see if the extra weight and vibration will open up a gap that I can work with. Don't know if it will work but it's worth a try. I've got about 150lbs of weights I can hang on the lower with ratchet straps. If it works then I'm good to go, if not I'll have to resort to something more drastic I guess.

 

[Ol Sarge]

Eureka, I finally got the lower unit off and the water pump changed. I removed all the lower unit bolts and I hung bar bell weights from the lower with ratchet straps. I let the weights hang there and ran the motor. I guess the vibration along with the additional weight broke the drive shaft loose from the power head and it came off. I did leave a bolt on each side of the lower unit in there about 3 or 4 turns in just in case it did break loose. Worked like a charm. Hope this will help someone else having the same problem. Thanks guys for all input and suggestions. I really appreciate it.

 

[interalian]

Good job! How rusty/crusty are the splines on the top of the drive shaft? And was the O-ring there?

 

[Ol Sarge]

Good job! How rusty/crusty are the splines on the top of the drive shaft? And was the O-ring there?

The splines actually looked really good and had clean grease on the splines. I couldn't find any reason why it was stuck. There wasn't an O ring of any kind any where. I was wondering if there should have been when I had it apart.

 

[boobie]

Glad to hear you got it and was glad to hear it worked.

 

[oldboat1]

for reference: http://ww2.iboats.com/Gearcase/dm/ca...iew_id.1540342 (O-ring #58)

 

[F_R]

I would have expected the o-ring would be in an internal groove in the end of the crankshaft on that model. But maybe not (???)

 

[Ol Sarge]

for reference: http://ww2.iboats.com/Gearcase/dm/ca...iew_id.1540342 (O-ring #58)

There was a large, 1 1/4" inside diameter, O ring in the kit but it was way too big to fit the drive shaft any where. It must have been for another model engine. I looked at the drive shaft top and bottom and under the water pump impeller for an O ring and there wasn't one. The only O ring in the kit was that large one.

 

[Ol Sarge]

I would have expected the o-ring would be in an internal groove in the end of the crankshaft on that model. But maybe not (???)

The factory shop manual didn't mention or show an O ring of any kind. I hope there isn't one that is supposed to be there.

 

[interalian]

O-ring is 310585. If your kit didn't include one, you should get one. Clean off all the old grease and coat the splines with Triple-Guard grease (or a good marine equivalent). Keep grease off the flat end of the shaft to prevent hydrolocking when re-assembling.

 

[Ol Sarge]

O-ring is 310585. If your kit didn't include one, you should get one. Clean off all the old grease and coat the splines with Triple-Guard grease (or a good marine equivalent). Keep grease off the flat end of the shaft to prevent hydrolocking when re-assembling.

Since that O ring wasn't there I'm assuming it goes at the upper end of the drive shaft just below the splines. Is that correct? What are the results of not having it there?

 

[interalian]

There should be a groove near the top, just under the splines. The O-ring is there to keep water out and the grease in.

 

[Ol Sarge]

There should be a groove near the top, just under the splines. The O-ring is there to keep water out and the grease in.

When I inspected the drive shaft upper end I specifically looked for an O ring grove in the shat and there wasn't one so I can only assume that on this model it doesn't use one. It gets really confusing what one model uses and what it doesn't . I guess if you've been working on outboards for years you get to know the differences but for a guy like me that doesn't do it for a living it can be a bit frustrating trying to figure out what's right and what's not. Especially if someone else has worked it before and didn't do it right.

 

[racerone]

The o-ring is in the crankshaft !!

 

[F_R]

The o-ring is in the crankshaft !!

That's what I say also. They started putting them in the crankshaft way back in the late 1970's. It is shown on the crankshaft page of the 1992 70hp parts book. Part number 0310585.

 

[Ol Sarge]

That's what I say also. They started putting them in the crankshaft way back in the late 1970's. It is shown on the crankshaft page of the 1992 70hp parts book. Part number 0310585.

That's a really strange place to put an O ring. I've gone through the factory shop manual several times and can't find any mention of it any where. I'm guessing the only way to change it would be to pull the power head. I really hope I don't have to do that for any reason. I got the water pump changed and everything seems to OK so far.