OMC Stringer Problem

Wow, that's not a pretty picture. Your oil intrusion issue could definitely be the seals and orings. We want it to be that - lol. The ball gear should turn by hand fairly easy, soulds like some occlusion somewhere. It is fairly easy to remove, just 4 bolts if you can get to them with the gear not moving, ouch! I'm guessing you have a dead blow mallet, this makes it easier to remove the ball gear housing along with a small pry bar. Be sure to use the same shims when replacing the ball gear housing. From the amount of oxidation it looks like you are going to need some large pipe cleaner type brushes to get the pinion housing and gearing housing cleaned up inside. You are also going to want to clean the water passages going to the pump housing. If you can find it in your area, get some SaltAway and soak all your housing components for several days before you attempt cleaning. Check all the roller bearing surfaces also, if they are pitted you will want to replace them. Incredibly they are standard automotive bearings available from Timken or BCA Bower. If the bearings and the races(cups) look ok just soak the bearing in light oil or WD40 or such for several days. By the way, SaltAway is available on line. It is a great product and used with diligence will prevent much of the oxidation you see in your unit.


www.saltawayproducts.com

Good luck!

 

Thanks for that

It doesn't look good though, does it?

I think I can see how the oil is getting into the impeller housing (or how the water is getting into the upper reservoir) now - I'm guessing the lower o-ring on the bearing housing has failed and allowed water to cross between the impeller outlet and the oil reservoir...well, hopefully that's all it is...to be honest, I can't see how else it could leak.

I'm going to remove the main drive shaft and gear today and then flush the residual oil and see if I can find some SaltAway at one of my local chandlers...the amount of salt deposits and weird slime-things in the water channels is amazing!

Thanks for your help (again!)

Paul

 

Did you mention whether you tried cranking the engine since repairs yet? I've heard of people replacing engines thinking they were seized only to try cranking the new engine thinking it was seized too only to find out it the was the drive the whole time. A broken shaft in the drive could cause both seizing and oil leakage. Plus it's a bad idea to leave the drive in the up position for a long period of time as the oil won't lubricate the seals and hard parts as it's settled in a place where it was not designed to be. In fact it'd be a good idea to keep the oil spread around when you can. Otherwise, seals will dry up and become brittle and hard parts such as gears will rust.

 

Well, I had the engine stripped, examined and completely rebuilt - it was definitely seized due to overheating. I could tell even before stripping it that it had dramatically over-heated, as there was a temperature marker on the block that had peeled off due to heat...

Having now stripped the drive, I'd say the oil would keep the various seals (of which there are actually very few) lubricated whether it was in the up or down position. The oil filled areas in this particular drive are basically two vertical cylinders and any seals are either at the bottom of them or are isolated from the oil altogether. None of the seals showed any sign of degradation at all, which is what was confusing...

Anyway, all of this is academic now, as buying spare parts (even buying the right oil!) for this drive is impossible due to its age. In stripping it down, I discovered the top casting was cracked and essentially beyond repair, so I'm removing the whole sorry mess and bolting an outboard on to the boat, instead.

Quite annoying, considering I had the engine rebuilt at pretty much the cost of a good outboard...

Cheers,

Paul

 

If you lived in Newport News VA, I have an upper gear case stringer. It is the
long shaft version. This one is an earlier version from I think 1968.
In Chesapeake, VA there is a used boat place. When I was last there they had hundreds of gear cases just laying out.

http://www.budgetboats.net/

 

Yep, that's the problem - these things are dead easy to get spares for in the US, but in the UK I can't even get the oil it needs... I must have contacted a dozen places in the US that sold spares - of the three or four who replied to me, none of them were interested in shipping parts to the UK...