12-71 Transmission Oil Change?

[racclarkson@gmail.com]

I’m bringing this old thread back to life because I was reading my Twin Disc MG-514C service manual and it recommends a 6 month or 1000hr interval for oil and filter changes. I am using the same oil as in my engines: NAPA low ash 40wt. Is this still considered good procedure?

Six months? That seems a bit pointless, especially given the 1000 hour alternative.

[SKYCHENEY]

Changing the filters on those is kind of a PITA. I would change oil every 3-5 years and filter every other time if you only put 100hrs/year on them. You never stated how much you run them.

[dottieshusband]

FWIW.. The 514c manual called for 9 gallons, but in my boat, it has the shallow case and only took about 6 gallons. I used shell rotella T1 because it was the only engine oil I found that said it was good for transmission service.