Yanmar's engine manual for the 2GM20F says to use 30 weight engine oil in my boat's the Hurth type transmission. But a link to the C-34 org site posted recently on this forum quotes Carl Hurth as saying "Never use engine oil in a transmission"....."Always use ATF (automatic transmission fluid) in the transmission". Sounds like advice straight from the designer's mouth!!! But a Google search shows that Carl Hurth marine transmissions company was bought out by ZF some time ago. Is his advice still good? I suppose he could still be designing for or supporting the ZF company. Any of you engine/ transmission repair experts have any coments on these two conflicting pieces of advice?
Hurth transmission oil type
- Thread starter jprieto
- Start date
- Status
30 weight oil
According to a diesel repair class at Mack Boring, the East Coast Yanmar distributor, there are two types of transmissions. One type you should use the same oil in the transmission that you put in the crankcase. The other type is for automatic transmission fluid. Go with what the manual says. When I purchased my boat the PO had put AT fluid in the transmission. The Yanmar manual said to use 30 weight oil. I asked the instructor at Mack Boring about the difference. He said not much but drain the AT fluid and replace with 30 weight oil. I have done so and have had no problems in five years. I do change this oil every year and it is as clean when it comes out as when it went in.
According to a diesel repair class at Mack Boring, the East Coast Yanmar distributor, there are two types of transmissions. One type you should use the same oil in the transmission that you put in the crankcase. The other type is for automatic transmission fluid. Go with what the manual says. When I purchased my boat the PO had put AT fluid in the transmission. The Yanmar manual said to use 30 weight oil. I asked the instructor at Mack Boring about the difference. He said not much but drain the AT fluid and replace with 30 weight oil. I have done so and have had no problems in five years. I do change this oil every year and it is as clean when it comes out as when it went in.
Yep, little difference
An example is the Gear-vendors overdrive in my 69 Camaro. Twenty some-ott years ago when I bought it, the manual called for 30 weight motor oil. This unit shifts like an automatic transmission. Well, with that oil, in my climate, when cold, it would take forever to shift. The oil wasn't flowing fast enough to the accumulator. (never-mind, sorry) I called the company a couple years later. They said "Dexron it!" (ATF) They sent me a kit to do the conversion. It was a lighter spring for the accumulator. That's it. Works great.
An example is the Gear-vendors overdrive in my 69 Camaro. Twenty some-ott years ago when I bought it, the manual called for 30 weight motor oil. This unit shifts like an automatic transmission. Well, with that oil, in my climate, when cold, it would take forever to shift. The oil wasn't flowing fast enough to the accumulator. (never-mind, sorry) I called the company a couple years later. They said "Dexron it!" (ATF) They sent me a kit to do the conversion. It was a lighter spring for the accumulator. That's it. Works great.
Look on the transmission!
There should be a label on the back or side of your transmission with the make, model, reduction ration and recommended oil type.
There should be a label on the back or side of your transmission with the make, model, reduction ration and recommended oil type.
- Status