On the subject of oil: The gearbox nameplate appears to specify (if I'm reading it right) SAE 20/30 HD.
1) Does this make sense, or am I reading it wrong?
2) How important is the HD part? Automotive suppliers I've called have single-weight SAE 30, but not HD, and when they hear the word 'diesel' they tell me I probably want the HD.
Okay, three questions:
3) Where is the HD version to be had? Is this stuff un-shippable, can't be ordered online, etc. ?
Thanks in advance from the poor ignorant n00b.
My gear box says the 30/40 HD. So I can use either 30 weight or 40 weight oil. I use the 30 weight and you can too. My engine calls for 30 weight for the temp range I operate in. So I can use the same oil in my engine- makes life easier as need to have on hand only one type of oil. Check your manual if you can do the same. You must use Diesel rated oil in the engine- It should be also rated Heavy Duty. DO NOT USE GASOLINE ENGINE OIL in the engine.
I get my gear and engine oil (for a yanmar 3gmd) at Walmart. I get the Rotella (Shell Oil I think) Straight 30 weight oil that is rated for Diesels- Note jug says HD of front- Heavy Duty. It comes in a 4 quart plastic jug and sells for about $17. West Marine sells the same oil but at about $5 more. I use the same oil in my engine- but my manual says straigh 30 weight (diesel rated) is ok. The 30 wt should be good for your transmission. Check your engine manual if it is ok for the engine. Make sure you use oil rated for Diesel engines, like the Rotella T1.
Here is a source:
Rotella® T1 is an easy-flow single grade oil provides quality lubrication consistent performance and excellent wear protection in diesel engines. Low ash content to minimize formation of deposits and to help keep intake ports clean. Outstanding oxidation resistance to help maximize service life. Excellent rust and corrosion protection. Optimized dispersants to help prevent engine sludge and varnish deposits.
What others have said is correct. My engine will not come out of gear if it is left in gear while sailing. The force on the prop and prop shaft jam the gears. Keep her in neutral while sailing- and let prop free spin. You can install shaft brake if you do not like the spinning, but unless you are going to cross an ocean, not really needed.
As others have said, do not over fill the gear box or the engine with oil. Looks like the gear box only takes 0.25 Li about 1/4 of a quart of oil- not much!.
Be carefull what bolts you loosen on the engine or the transmission, you could accidently change and adjustment you cannot get back.
The best way to get the oil out is by sucking in out through the dip stick hole. Many marine engines do not have a drain plug. By draining the oil you could easily flood your bilge with oil and have a big coast guard fine if any gets pumped over board.
I know this is expensive, but it has worked well for me and saves much time (I have tried the hand pumps and found they do not work well):