Engine repair: Seized shaft bearing on a 7.5 Merc

[Matt]

Recently was given a 1971 7.5 hp merc from the original owner. Everything is really clean in and out except the damn thing seemed to be completely seized when I got it. The shift linkage works fine, but the main drive-shaft is where I found my problem. I started by removing the fly wheel cover and trying to rotate it by hand to no avail. I then removed the lower unit of the motor to inspect it. After removing the water pump assembly I found a HEAVILY corroded bearing between the main shaft and the gearcase inside of the lower. I was wondering if anyone had opinions on removing or freeing this bearing. Do you think it could be destroyed and removed in pieces without damaging components on the other side of the bearing?

Input appreciated.

Matt

[flippinfool]

IT WAS FREE! DITCH IT OR PART IT OUT!

[Anonymous]

Most of those repairs are pretty straight forward and easy. The tough part is figuring out why it went south. It should be just a matter of removing the old one and putting a new one in. If there's a water leak in the case somewhere that caused the corosion that will need to be repaired as well. Run it on the stand for a long time and take it apart again after the initial repair.

[Matt]

The reason for the original seizure was from the motor sitting. It sat for 3-5 years since I've ripped it apart. The water leak thing is a decent theory as well I will have to look into that.

I found a place to buy a replacement bearing, but still don't know how to remove the existing one!

Matt

[Matt]

IT WAS FREE! DITCH IT OR PART IT OUT!

If it turns out to be just the bearing the part it only 10$ and that would be pretty stupid. Everything about the motor is mechanically great, so far just the one bearing appears to be the problem child.

[Bodofish]

You might need a bearing puller. If you don't have access to one of the right size you can usually make one with a long bolt and a couple of nuts and some fender washers. Juice it up good with some break free or wd to start on the rust. You can also tap lightly on the race to set up a vibration to break the rust with the oil on it. Go for gusto sounds like an easy one.

[swedefish4life1]

E-:cheers: ARE YOU READING THIS ABOUT SITTING FOR YEARS ?#-o THAT COVERS OUTDRIVES , MOTOR'S SEALS AND WORSE THEY ALL DRY:-$

YOU CAN BEAT THE SNOOTER OUT OF A MOTOR WILL IT DECREASE ITS SERVICE and LIFE IF THE OIL , FILTERS LUBE POINTS ARE HIT AND WITH REAL CARE MAYBE or NOT??

IF THE MOTOR, OUTDRIVE OR JETPUMP IS NOT OVER REVED :bounce:

BUT ANY MOTOR, SHAFTS, SEALS, GASKETS AND A LIST LONGER THEN JOHNSON:colors: SITS AND IS NOT STARTED THE SEALS LUBED AND MORE EVEN WITH PRELUBE BEFORE LONG TERM STORAGE AND CARE OVER TIME ITS TOAST!!! $$$ ON IT DRY AND WORSE

I ALWAYS SAY LUBE AWAY:colors: :chef: !!!!

[Matt]

I got advice on another forum that the key (in reference to the bearing) is the removal of the shaft itself which requires also the removal of the prop and prop shaft etc. Gotta get the shop manual if I am to proceed any further.... opinions on if I should move forward or just scrap it?

my biggest fear is getting the bearing out to find 10x the corrosion beneath it/in the gear case.


Matt

[Bodofish]

Never know till you try. as the Swede says oil the crap out of it before you try and start. Probably not a bad idea to buy a few gaskets and pull the pistons to make sure they're all free and good and slippery.

[Bscman]

Whats the downside? A little lost time?
Better than watching TV isn't it?

Best case scenario you get a running motor for under $40 and a little more knowledge to throw in the bank.

Then again, I'm a tinkerer by nature so I wouldn't even have to ask!