Transmission Oil
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So ... the tranny manufacturer says ... what?
IMHO - any transmission that shifts w/o benefit of synchronizer rings and engages by jamming the teeth of the gears together to mesh (as does a boat tranny) has to be wearing off metal from the gear teeth. This metal is in suspension as the gears turn. This same oil lubricates the trannies bearings as well. That's why most transmissions of this type have a magnet in the bottom of the case to trap the shavings.
I change ny gear oil every season (per manufacturer's recommendations).
IMHO - any transmission that shifts w/o benefit of synchronizer rings and engages by jamming the teeth of the gears together to mesh (as does a boat tranny) has to be wearing off metal from the gear teeth. This metal is in suspension as the gears turn. This same oil lubricates the trannies bearings as well. That's why most transmissions of this type have a magnet in the bottom of the case to trap the shavings.
I change ny gear oil every season (per manufacturer's recommendations).
I, too, change the transmission oil in my Yanmar every season. When I took a diesel engine maintenance course many years ago, I still remember the instructor saying something to the effect about how a few cents worth of oil could potentially save you thousands in repairs. The only bad experience I know of, however, involves a friend with an aging Hunter 27 who never checked, changed, or added oil to his transmission. It eventually burned up costing him a bundle and a lost season....
Every season or when
I remember to do it.
Naw, we have a regular schedule based on engine hours, in the engine log. When we got the boat, it took me a while to "get into things" so it was two or three years. The PO had a yard do his work. While I've extended the period between changes, I always feel good about exchanging dirty lubricant with clean stuff, even if it gets filthy in two seconds. About once every two years, I run 150 hrs a year.
I remember to do it.
Naw, we have a regular schedule based on engine hours, in the engine log. When we got the boat, it took me a while to "get into things" so it was two or three years. The PO had a yard do his work. While I've extended the period between changes, I always feel good about exchanging dirty lubricant with clean stuff, even if it gets filthy in two seconds. About once every two years, I run 150 hrs a year.Two questions
Two questions:
1) On my boat, it doesn't say whether to check the level with the dip stick screwed in or not. Does anybody know which it is?
2) The above question is almost irrelevant because when I changed it, the new oil was so clear that I really couldn't read the diptsick anyway. Any solutions to this problem?
Two questions:
1) On my boat, it doesn't say whether to check the level with the dip stick screwed in or not. Does anybody know which it is?
2) The above question is almost irrelevant because when I changed it, the new oil was so clear that I really couldn't read the diptsick anyway. Any solutions to this problem?
1. Unscrewed, resting on the top.
2. Use a paper towel and roll the end of the dipstick on that - it'll become "clear" to you immediately, or, better yet, keep what you have taken out in a clear plastic cup, put new oil in another cup to the same level, then check with dipstick as noted.
Yearly
Yearly for me. It's simple, and one quart of ATF costs me $3.42 as I just did it yesterday. A replacement Hurth V-Drive for me is about 4k+.. $3.42 vs. 4k vs. piece of mind..
Re: Yearly
My transmission uses the same grade oil as the engine. It is as clean to day as when I put it in ten years ago. A few drops on a glass plate are completely free of particulates. The transmission fluid in my car hasn't been changed in a hundred thousand miles.
My transmission uses the same grade oil as the engine. It is as clean to day as when I put it in ten years ago. A few drops on a glass plate are completely free of particulates. The transmission fluid in my car hasn't been changed in a hundred thousand miles.
What type of transmission are we discussing? Conventional, saildrive or outboard motor?
Re Capn Ellis' remarks; surely all proper marine transmissions are constant mesh with clutches to engage forwards or astern - at least mine on my Yanmar is. Also the set up is that the gear shift requires the throttle be closed when the shift is in progress.
IMHO only the smaller outboard motors have a dog clutch for gear selection.
I agree with Ross that a 'conventional' gearbox only needs an oil change if one suspects something may have contaminated it - and it is so easily checked too.
Saildrives, spending their lives underwater, rely on good oil seals to keep the water out - and no fishing line around the shaft! Probably best to change oil as per makers spec or annually just to be careful.
Small outboards - why bother? They always seem to leak water in and also seem to run perfectly well on a blend of EP90 oil and seawater. I suspect they are designed to. They hardly even seem to suffer internal rusting and corrosion. I only do mine when I have the bottom end on the bench for other reasons - probably at 5 yearly intervals. I just let the old gunk drain and refill with gear oil and don't worry about the seals. Curiously they don't even seem to leak oil out even when laid in the car trunk.
Re Capn Ellis' remarks; surely all proper marine transmissions are constant mesh with clutches to engage forwards or astern - at least mine on my Yanmar is. Also the set up is that the gear shift requires the throttle be closed when the shift is in progress.
IMHO only the smaller outboard motors have a dog clutch for gear selection.
I agree with Ross that a 'conventional' gearbox only needs an oil change if one suspects something may have contaminated it - and it is so easily checked too.
Saildrives, spending their lives underwater, rely on good oil seals to keep the water out - and no fishing line around the shaft! Probably best to change oil as per makers spec or annually just to be careful.
Small outboards - why bother? They always seem to leak water in and also seem to run perfectly well on a blend of EP90 oil and seawater. I suspect they are designed to. They hardly even seem to suffer internal rusting and corrosion. I only do mine when I have the bottom end on the bench for other reasons - probably at 5 yearly intervals. I just let the old gunk drain and refill with gear oil and don't worry about the seals. Curiously they don't even seem to leak oil out even when laid in the car trunk.
The transmission is a place where the virtues of synthetic oils shine. They resist temperature breakdown and maintain viscocity for much longer periods of time. Unlike in an engine where the oil gets dirty and contaminated by combustion byproducts in a transmission the oil is encased in a clean environment with less heat exposurse. I'm currently replacing the oil every three years but can see that it would easily last fro 5 to 10.
check with the dipstick Unscrewed
According to Westerbeke, on my 13A with a Hurst transmission, one checks the fluid level with the dipstick just resting on top, NOT screwed in. I had been screwing it in which is a 1/4 " lower and the level was "right". But not really, it was 1/4" too low so I've added some more.
According to Westerbeke, on my 13A with a Hurst transmission, one checks the fluid level with the dipstick just resting on top, NOT screwed in. I had been screwing it in which is a 1/4 " lower and the level was "right". But not really, it was 1/4" too low so I've added some more.
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