richardabeattie
Well-Known Member
I have a Yanmar 2GM20 and the recommended oils are 15W-40 for the sump and SAE 30 for the gearbox. Can anybody tell me why they need to be different? Would it be so very wrong to use 15W-40 in the gear box?
Sump oil and gearbox oil
- Thread starter richardabeattie
- Start date
KellysEye
Well-Known Member
If that is what Yanmar say stick with it, there is a reason for it. If you are interested call them and ask why the difference.
rob2
Well-Known Member
This is purely surmise as I'm not altogether familiar with the Yanmar gearbox. Many gearboxes use either a plate or conical metal-to-metal clutch and this will slip if using multigrade oils. I made this mistake with an old Albin installation and had to put flushing oil in the box and tug at the mooring for half an hour slipping her in and out of gear before refilling with the proper stuff. Straight grade oils are sometimes available from supermarkets but I got mine from Morris (the oil supplier, not the car manufacturer).
Rob.
Rob.
lw395
Well-Known Member
Engine oils and gear oils have different additives to cope with different problems.
Engines have to cope with combustion by products, gearboxes have to cope with the gears shearing the oil molecules, and be resistant to the gears making froth.
It's quite possible there is an oil that meets both specs.
Most motorcycles have the gears in the sump, so it's possible.
But the gearbox oil does not need changing that often, it's no real hardship to get the right stuff for it, and no advantage in using anything fancy as the box is unlikely to wear out anyway IMHO.
Engines have to cope with combustion by products, gearboxes have to cope with the gears shearing the oil molecules, and be resistant to the gears making froth.
It's quite possible there is an oil that meets both specs.
Most motorcycles have the gears in the sump, so it's possible.
But the gearbox oil does not need changing that often, it's no real hardship to get the right stuff for it, and no advantage in using anything fancy as the box is unlikely to wear out anyway IMHO.
wotayottie
Well-Known Member
Other way round. If you pout hypoid gear box oils or other oils with very high lubricity ( synthetics for example) in a box with a cone clutch, the clutch can start to slip and wear. With my 2GM, I had this problem and when the box was re-built the engineer who's business as a Yanmar agent involved a lot of small inshore fishing boat maintenance recommended using straight SAE 10 engine oil in the box. Worked well for years after that.
rotrax
Well-Known Member
I think you will find that Morris cars have not been available for some considerable time........................
John100156
Well-Known Member
Having recently posted and receiving good advice regarding a good quality engine oil for my TAMD63P engines, I moved on to my ZF IRM220A1 gearbox oil. The Volvo manual stated only mono-grade SAE30 oil, so I emailed ZF direct. They provided me with a list of oils that could be used, to include multi-grade 15W40!
Just to be certain, I questioned this with them again, they re-confirmed that yes, Shell Rimula R3X 15W40 oil definitely could be used, they manufactured the gearboxes. This meant I only required one oil for both engine and gearbox. They said their recommendations also included the use of SAE30 oil or SAE40 in hotter climates but this was not the only suitable oil.
Just to be certain, I questioned this with them again, they re-confirmed that yes, Shell Rimula R3X 15W40 oil definitely could be used, they manufactured the gearboxes. This meant I only required one oil for both engine and gearbox. They said their recommendations also included the use of SAE30 oil or SAE40 in hotter climates but this was not the only suitable oil.
vyv_cox
Well-Known Member
Very strange, because the recommendation for my 3GM30 is for 15W/40 in both engine and gearbox. If you are using the API CD generally recommended for the GM series there is only a very small additive content anyway.
lw395
Well-Known Member
According to this:
http://www.yanmarhelp.com/i_box2.htm
Yanmar seem to recommend a variety of oils for different boxes.
http://www.yanmarhelp.com/i_box2.htm
Yanmar seem to recommend a variety of oils for different boxes.
James_Calvert
Well-Known Member
Your question caught my eye because I've been doing something similar for a good number of years. The oil specified for my Bukh 20 is SAE30 for both the engine and gearbox. Having established that 20/50 multigrade would be ok for the engine, I've been using the same oil for the gearbox as well.
Relieved, but not surprised to infer from advice so far that I'm doing nothing wrong...
Relieved, but not surprised to infer from advice so far that I'm doing nothing wrong...
RestlessL
Well-Known Member
Bukh now list 15/40 multigrade (e.g. Rimula X) for both engine and gear box.
See the updated version of the DV24 manual for details:
http://clouds.nl/cyfu/__bukh-downloads
bajo
Well-Known Member
I have a Yanmar 1gm10 with a KMP2 g/box in my small sailboat and I was unable to get a 40 grade CD API oil and had to settle for a 15-40 Castrol CRB TURBO API CH-4SJ ,but I live in the Caribbean an Yanmar recommends 40 grade for my temperature zone Should I change it to a 40 grade when available or leave well alone
lw395
Well-Known Member
The oil you are using meets every requirement of an oil sold to CD spec, in fact betters it by a wide margin. In my opinion it will be fine, but as the oil content of the 1gm is small, I tend to think its worth changing it fairly often.