|Sabb model G - advice please
Post Number: 1
|Posted on Wednesday, June 22, 2016 - 09:05 am: ||
Having struggled to align my engine perfectly sometime ago, I have foolishly been running the engine with a visible wobble at the fore end of the stern tube. I have now developed an oil leak and the engine sounds different (a little rough). I think the new noise is more prevalent when running in gear but it's tricky to be sure. The oil leak is coming from the gear housing which is located between the cylinder block and the reverse gear (clutch housing). Having checked the oil levels in both the engine sump and reverse gear I noticed a rise in oil in the reverse gear and a loss in the engine sump. According to the manual http://nettbutikk.sabb.no/cda/viewfile.aspx?id=75 this could be blow-by in cylinder or a leaky oil seal in the gear housing. The engine starts perfectly and judging by the evidence of the oil leak I am presuming it is the oil seal. My question is this: could I have damaged the bearings in the gear housing as well as the oil seal? Could this explain the noise? Is it possible to damage this through running a misaligned engine? Also the rear oil seal on the reverse gear shows no sign of leaking and the reverse gear is working perfectly. Would the misalignment not damage the reverse gear before the bearings on the cam shaftgear housing? Before I remove the saloon table and drag the engine out, am I barking up the right tree? Any advice on how to proceed greatly appreciated. Thank you for taking the time to read such a long post.
Post Number: 876
|Posted on Saturday, June 25, 2016 - 08:57 pm: ||
My experience has been that the shaft log wears out to an egg-shape before the bearings on the gear box wear out.
The shaft log was brass naterial in my boat.
After I aligned the engine and shaft, (some 20 years ago)I've had no issues .
I found the best way to align the engine and shaft is to have a small separation between the engine side hub and the shaft side hub, and tweak the engine mounts until I had the same dimension on the North, South and East and West positions
( should be within 5 - 7 thou).
It helps if your hubs are snuggly fitted i.e. no wobble.
In my engine the gear box and engine shared the oil sump.