Gearcase lube

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Gearcase lube

Postby Backyard Bob » Mon May 09, 2022 5:44 pm

Can anyone recommended a modern oil/lube for the crankcase on a 165 motor? Thanks.
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Re: Gearcase lube

Postby Emerica1975 » Mon May 09, 2022 10:11 pm

I don’t know of a new modern lubricant. I use 40 weight non detergent oil and it seems to work alright. I think the guys here might actually recommend 30 weight non detergent oil. But all I could get was the 40.
Hope that maybe helps a little.
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Re: Gearcase lube

Postby pumpguy » Tue May 10, 2022 10:56 am

In addition to my interest in Harley Hummers from back in the day, I am a fan and user of other 2T bikes, namely Maicos and Kawasaki KDX 220s. Many users in these groups are recommending and using ATF, Type F.

If you think about it, automatic transmissions are full of clutches, gears, and bearings, and this fluid goes for years, sometimes even decades without changing. This fluid is specifically designed for just this service.

The problem with using motor oils for this application is you have to be careful they don't contain friction modifiers which can cause slipping clutch, and there are so many flavors to choose from.

Yes, I know many 4T bikes use the same oil for engine and transmission, and for these, special oils are available along with advice not to use oils with friction modifiers.

Oil debates are never-ending. This post is just something more to add to the debate.
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Re: Gearcase lube

Postby Brent » Tue May 10, 2022 11:13 am

Years ago I rebuilt a 1946 Indian Chief trans that only had 17k miles on it and it was worn out. I had a Sportster also. It used H-D Sport-trans fluid for the shared clutch/gearcase so I thought "What the heck" and ran that in the Indian. 17k miles later I checked the trans and found virtually no wear on the gears along with no clutch problems. The ATF fluid sounds logical.
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Re: Gearcase lube

Postby hennesse » Tue May 10, 2022 11:31 am

Backyard Bob wrote:Can anyone recommended a modern oil/lube for the crankcase on a 165 motor? Thanks.

I think you mean transmission, not crankcase.

The old Harley manuals say "Harley medium heavy 75" motor oil, which was SAE 40 with detergent. So any modern SAE 40 motor oil will be fine. For this application, and the light use most of us give our bikes, SAE 30 detergent motor oil should be just fine.

Certain types of equipment, like air compressors, specify non-detergent oil. But I don't see any reason to use it in a our lightweights.
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Re: Gearcase lube

Postby 2ma2 » Tue May 10, 2022 10:51 pm

Fwiw On my road king I tried the recommended gearbox specific oil as an accepted alternative to motor oil. I noticed the shift points were more positive and felt better with the motor oil in the box, I’ll be switching back at the next oil change. On the hummer I used 30wt non detergent from ace hardware per recommendation on this forum
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Re: Gearcase lube

Postby Backyard Bob » Wed May 11, 2022 7:42 pm

Dave, ya caught me. It must have been beer 30 when I wrote it. I meant gearcase, not crank case. So far, from what I've read, it looks like these bikes are pretty forgiving with whatever oil we use. Truth is I put about 10k miles on my first bike at 14 (a Honda 90) and owned enough bikes along the way to where the relationships were fun but not long lasting... and that was part of the fun. The bikes I've picked up along the way were mostly used and abused by people who ran'm hard and put'm away wet. Putting them back on the road was another type of fun.
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