The transmission you need is a Hurth 10 with a 2.1:1 ratio.
The tranmission is the weak link in the drivetrain though. The 4-108 at 51 HP @4000rpms is right on the limit for the hurth 10 you might want to install a ZF12 (ZF bought out Hurth) but you will need to move the engine forward or shorten the prop shaft, as the ZF12 has a larger casement.
The Perkins 4-108 is a awsome engine old school tech heavy and strong. However they leek oil from front and rear oil seals. If a perkins stops leeking oil then there probably isnt any left in the oil pan.
02-12-2010 07:39 AM
You're welcome. The First 38 is an excellant yacht. Andy and Liz Copeland traveled the world in theirs (Bagheera) and she's still going strong with their children now in command. The 4-108 is arguably one of the strongest engines and, with proper maintenance, will run 10,000--and some claim 20,000--hours. They do tend to leak a bit of oil from time to time but that can be limited by keeping the oil level at the mid-point on the dip-stick. For what it's worth, there are more 4-108's running tractors, generators and farm equipment around the world than boats so parts are readily available.
02-11-2010 08:20 PM
Thank-you so much for the information and phone #. I really appreciate your help!!!
02-11-2010 06:24 PM
The First series drive train of that era where typically 4-108's linked to Hurth 2.1:1 transmissions. If you have the boats HIN number, you can get specifics from Ward Richardson at Beneteau USA (01-843-629-5300).
02-11-2010 02:06 PM
Transmission used in a 1984 Beneteau first 38
Just wondering if anyone knows what transmission was installed in the 1984 Beneteau First 38. It has the original Perkins 4108 diesel with 4918hrs. Not being familiar with this type of engine, I was also wondering when I would need to consider rebuilding the engine?