Shaft wear

[Randy Burns]

I'm in the process of repowering and am looking for advice. The original brass drive shaft shows .006" of wear and some scoreing at the cutlass bearing, but not to deep. At the stuffing box it is worn about .015" The shaft is true & I'm replacing the cutlass bearing. Should I reuse the shaft?

 

[tmason]

some sources if you need them

I didn't have a choice when I repowered. My original shaft was 3 inches short. You won't find a replacement today that isn't stainless steel. I bought one at the link below. You've perhaps heard arguments about the need for flexible couplings. (Pro: you need some flexibility in the driveline. Con: it won't save your propeller or tranny in a catastrophic event because a small diesel isn't powerful enough to tear it up.) A coupler will add an inch to the driveline if you decide to go with one. I bought PYI's R&D coupler for $140. My bronze shaft was also scored at the head of stuffing box, but not back where it mattered, where the packing keeps out the water. I wouldn't think uniform wear on the packing surface would matter much. The cutlass bearing surface is more critical.

 

[Randy Burns]

Thanks & Thanks Ed for H37 Repower

I had decided to go the new route and it looks like this will save some money. The old Yanmar had a vibration damper so I bought a Drivesaver - a little different but I guess will work.

 

[Ed Schenck]

Good investment I think.

The new shaft is stainless and should wear better. Even so I had very little play at the cutless after all those years. The marine supply also faced the coupler and reinstalled with a new key. Add a key for the new prop and a new cutless and we are ready for the water. Maybe next week!!The engine template looks good. It seems to be 1/2" in thickness, same as the front mounts. Just remember that the rear mounts are only 1/4" in thickness. How are you getting the required 17" width with the new engine? I assume it is a Yanmar from the looks of the mounts in the picture.

 

[Randy Burns]

Lucky you - I'm looking at mid June

I assume your referring to the width (yes its a YM15)- it seems to be OK in the 27. I did have to grind down about a 1/4" of the beds at the stern mounts, to get centered within the vertical adjustment tolerance. I was about to drill for the motor mount holes when I read your post - since Im using a boom truck anyway, I'll take your advice and set it, mark it and lift it. - good idea