Prout needs a sail drive

[karenwoods]

What we need for the boat (1994 Prout) is a Volvo penta s120c saildrive.
There is a s120e on eBay ...are these interchangeable? We appreciate any nuggets of wisdom!
Captain Larry

[DougR]

What I recall is that most of the improvements to the 120 series saildrives that were significant enough to cause a model designation change were internal improvements. Things like the addition of shotpiened gears, or the addition of an internal slip clutch to protect gears, or coatings on the shift cone, etc. These wouldn't effect the interchangeability of drives, but might require different lubricants inside the drive.

But there are two things you should be aware of:
- Typically the drive was available in two different gear ratios : 2.2:1 and 2.5:1. You should be sure you get the same ratio replacement drive or you could be looking at having to change your propeller.

- The earlier series 120 saildrives used a saildrive mount that was basically an engine mount with bracket underneath to sit on the bellows clamp ring. I believe the 120e drive used a round trunion type mount that used a different support bracket to the clamp ring. It's possible that the rear plate on the gear case could be changed if necessary from the old to the new style.... but I'm not positive about that.

DougR

[karenwoods]

Thank you,Doug, for your detailed and helpful reply!
This is all good news to me!
Captain Larry