Best Transmission Oil

[Lotus54]

Synthetic oils for clutch is just fine. Just can’t have the ‘friction modifiers’ In most car engine oils.

I’ve been running synthetic for years and years with no issues at all.

Just as a note, ATF varies quite a lot from type to type. They are not all the same at all. That said, I have no idea how the different formulas would work relative to each other in a motorcycle gearbox/clutch.
I would speculate none would cause clutch issues- but that would certainly depend on the composition of the clutch material, amount of pressure, amount of slipping and of course heat.

[Johnno]

Some of the things you get told: The proprietor of a motorcycle repair and tyre shop who I consider a friend berated me for not using a specific 2 stroke gear box oil. It was Motul 5100 engine oil versus 5100 trans oil.

His reasoning was that a 4T oil would ruin my crank.

I wondered how it was going to get in there.

I said my understanding, and that's all that is, is that the trans oil 5100 doesn't have the stuff it doesn't need to be in the top of an engine.

The fact that the trans oil 5100 is a few cents cheaper might bear this out.

In the 1970's ( this was all trees then, no buildings ) the handbook told you to run 10w or sometimes 10W30 motor oil in the trans. My IT175F manual told me to run 10W motor oil in the forks. Guys started running ATF which is about 7.5W ( as far as I know ) in their forks and 2T trans. It worked well.

My point is, I am not sure of any ground braking technological ( can't believe I spelled that correctly, WIN!! ) improvements to the 2T trans. Okay the fibre isn't whale skin any more or something but it's still the same mechanically.

My favourite is: Why do you use a diesel engine oil in your trans, you should use a motorcycle pacific ( sic ) trans oil because your bike is toadally gonna blow up mang.

It's good stuff, that's why. My clutch doesn't slip ever and I can go over to my bike stone cold in first gear, pull in the clutch and push it.

If you are happy to use Motul ( I never had a problem with it ) or any other Motorcycle oil please continue.

If you start using Delo or any other diesel oil then do it because you looked into it, maybe spent an afternoon or 3 with a cup of something learning a bit about oil, it's make up and what it can and can't do.

Not because I said so.

Peace

Riding a 2018 Beta Xtrainer. Low speed technical rocky rooty steep 1 and 2nd occasionally 3rd gear riding. Air temps 90-95 high humidity. Hawaii.
I recently "Upgraded" from the regular Rotella Diesel oil which I have been running for 2 years to their Synthetic. Not sure yet if it is a coincidence but I am having some trouble with overheating since doing so. I also at about the same time installed a Rekluse radius CX clutch which I don't bog or run it in too high a gear so I don't believe I am creating more heat slipping the clutch...unless the synthetic oil is causing slipping.?
I spoke with my very knowledgeable mechanic and he said he recommends that I go away from synthetic oils for the trans/clutch. Wondering if you or anyone on here had an opinion on synthetic oils for transmissions with a wet clutch and if there is a problem.

As others have pointed out, synth oil is generally fine but read the fine print about friction modifiers. Clutches DO NOT like them.

[Mp5]

Been using Rotella T in everything I own for 15 yrs. Sleds, 4 stroke KTM, two strokes GasGas and Beta, lawn mowers and sxs. Even ran it in my Ultra Classic for 10 yrs...great oil at a great price

[Navigator]

I would def stay away from any oil that doesn't have clutch friction modifiers in it ie. diesel oil. People can say what they want just find a oil formulated for motorcycles and it will prob work fine.

[trich]

I've ran Rotella in my bikes the last 15 years, it good stuff!!!

[webmaster]

I usually stay out of discussions on oils and chain lube, but....

Rotella has a jaso ma2 motorcycle rating.

Jeff