HorizonblueDK
Petty Officer 1st Class
- Joined
- May 27, 2010
- Messages
- 355
Here is something I would like to show you, that doesn't happen that often.
A friend of mine has a 25 footer with a 280 drive and a 41 diesel engine. The original 40 engine was replaced by a previous owner.
On a trip last year, he heard a loud BANG, stopped off course to check what was wrong. Nothing apparently, so he continued, but not for long, and he had to be towed in, since there was only connection between the engine and propeller for a few minutes after the bang.
He took the drive off, and we dismantled it in my workshop. The first thing we saw was this.
Well ok, he must have hit something in the water, so he found another shaft on ebay.
We dismantled the lower unit, and what we saw, was beyond our imagination.
A tooth was missing, so he went back on ebay and found a gear set, helical cut, instead of straight. I recommended the helical cut, to reduce noise.
We have now assembled the lower unit again, and gone through the shimming process and checked the gear contact pattern and backlash.
First assembled the lower unit with shims, calculated according to the original Volvo manual, and the gear painted with marking dye. Here ready for a test, the propshaft is braked and the bearing race is held down with a home made tool.
After a few turns, in the direction the engine spins, the gear is taken out for inspection.
From what I can see and what the Volvo manual states, the contact pattern is where it should be.
The lower unit is now assembled with new seals. Now that we are working on the outdrive, we have knocked the water pipe in the upper unit out and removed the suspension fork, so that area can be cleaned and greased. Then the boat will be easier to steer.
I don't really have any questions, just wanted to show you a rare sight. You are off course free to ask questions.
A friend of mine has a 25 footer with a 280 drive and a 41 diesel engine. The original 40 engine was replaced by a previous owner.
On a trip last year, he heard a loud BANG, stopped off course to check what was wrong. Nothing apparently, so he continued, but not for long, and he had to be towed in, since there was only connection between the engine and propeller for a few minutes after the bang.
He took the drive off, and we dismantled it in my workshop. The first thing we saw was this.
Well ok, he must have hit something in the water, so he found another shaft on ebay.
We dismantled the lower unit, and what we saw, was beyond our imagination.
A tooth was missing, so he went back on ebay and found a gear set, helical cut, instead of straight. I recommended the helical cut, to reduce noise.
We have now assembled the lower unit again, and gone through the shimming process and checked the gear contact pattern and backlash.
First assembled the lower unit with shims, calculated according to the original Volvo manual, and the gear painted with marking dye. Here ready for a test, the propshaft is braked and the bearing race is held down with a home made tool.
After a few turns, in the direction the engine spins, the gear is taken out for inspection.
From what I can see and what the Volvo manual states, the contact pattern is where it should be.
The lower unit is now assembled with new seals. Now that we are working on the outdrive, we have knocked the water pipe in the upper unit out and removed the suspension fork, so that area can be cleaned and greased. Then the boat will be easier to steer.
I don't really have any questions, just wanted to show you a rare sight. You are off course free to ask questions.
