Twin Disc question for edb

Hi Mike,
only ones I ever worked on at The Dealer, here in OZ down under, were from vessels and went back into them after O/haul.
Most of these were small ones on D330, D333, 3208, 3116. If I recall correctly most if not all larger engines here had Cat Marine Transmissions on them.
Cheers,
Eddie B.

There are plenty of different marine gearboxes on the market to do this, providing you don't already have the maximum reduction which will be around 6:1. The most popular are Twin -Disc and ZF but for a cheap alternative there is also D-I from Korea, their deepest reduction is 6.95:1

Hi guys. Thanks for the info. I'll start looking at marine transmissions.

Hello
We have several CAT 3406C's running with Twin Disc MG5091 gearboxes at continuous ratings, 300hp @ 1800 Rpm.
The ratio is 3.0:1 therefore resulting in a shaft speed of 600 Rpm.
For example if your D342 was running at 1200 Rpm full load with a 3.0:1 transmission ratio, then the shaft speed would be 400 Rpm.
If you were to replace this installation (example) with a CAT 3406 engine of 1800 rpm then to maintain the same shaft
speed the transmission would require a ratio of 4.5:1 to produce the same shaft speed, i.e. 400 Rpm.
If you try to turn the propellar that was fitted to the D342 faster then you could find yourself overloading the engine.
If you go ahead with the re-engineering using a 3406 ensure that the transmission supplier does a torsional anaylsis of the drive
line, and uses the correct flywheel coupling to transmission as we have seen clutch plate failures as a result, Twin Disc know
of the problem.
Trust this is of assistance.
Best regards Gary