ben2go
Guru
Through research, I have narrowed my transmission choices down to two that will work the Beta 38 engine going in my boat. The two units are the PRM Newage PRM125 and the Technodrive/Twin-disc TMC-60-A. Both of these units are very similar in design and operate the same. Both are cone clutch style transmissions.
Let's start with the PRM unit. The PRM125 is an updated and upgraded version of the PRM120. I will have to cut down and angle my engine beds along with angling the engine up at 7 to 8 degrees or add a V-drive and reverse mount the engine. It will barely fit under the hatch. I may be forced to use solid engine mounts to get the engine low enough in the hull to use the PRM trans. I found this transmission has a 1500 hr rating between refreshes. It's rated for 5000 rpm input. It will take everything my engine has at 38hp and 3600 rpm. I also have a full shop service manual for this transmission. The UK canal cruisers love them. They brag about how much abuse and neglect they can take.
The Technodive/Twin-disc unit on the surface seems to be a perfect choice. It specs out just a little under the PRM125 but more than capable of handling my engine and boat. The one major plus is the TMC-60-A has a built-in 7 degree down angle. I couldn't find a recommended refresh time frame. Only a service guideline. I found a few naysayers on the TMC trans but no mention of a specific model number. This transmission would greatly simplify my driveline install, not that it would add much complexity to install the other set up. I would just have to spend more time measuring twice and cutting once to get the angle correct on the engine beds.
What do you guys think? Any experience with either of these transmissions? I'm leaning toward the Techno/T-D because of ease of installation, but it's hard to ignore the PRM's reputation of being drug through the mud in the UK canal system in narrow boats.
Let's start with the PRM unit. The PRM125 is an updated and upgraded version of the PRM120. I will have to cut down and angle my engine beds along with angling the engine up at 7 to 8 degrees or add a V-drive and reverse mount the engine. It will barely fit under the hatch. I may be forced to use solid engine mounts to get the engine low enough in the hull to use the PRM trans. I found this transmission has a 1500 hr rating between refreshes. It's rated for 5000 rpm input. It will take everything my engine has at 38hp and 3600 rpm. I also have a full shop service manual for this transmission. The UK canal cruisers love them. They brag about how much abuse and neglect they can take.
The Technodive/Twin-disc unit on the surface seems to be a perfect choice. It specs out just a little under the PRM125 but more than capable of handling my engine and boat. The one major plus is the TMC-60-A has a built-in 7 degree down angle. I couldn't find a recommended refresh time frame. Only a service guideline. I found a few naysayers on the TMC trans but no mention of a specific model number. This transmission would greatly simplify my driveline install, not that it would add much complexity to install the other set up. I would just have to spend more time measuring twice and cutting once to get the angle correct on the engine beds.
What do you guys think? Any experience with either of these transmissions? I'm leaning toward the Techno/T-D because of ease of installation, but it's hard to ignore the PRM's reputation of being drug through the mud in the UK canal system in narrow boats.