Synthetcs and wet clutches/brakes

[BGL990]

There has been much discussion here lately about synthetic oils (all of it interesting) and it reminded me of something I heard once. That is that synthetic oils probably shouldn't be used in applications with wet clutches or brakes (those where the friction plates are immersed in oil). The reasoning was that synthetic oil can cause more slippage of the clutch or brake. I'm not sure whether it was supposed to be the base stock or the additives that were "too slippery", but high Moly levels come to mind as something that might have that effect.

When I originally heard this it was in the context of the wet multiplate clutch in CBR600 sportbike I had, but many tractors (including my 990) have wet brakes and many power-reverser type transmissions have dual wet clutches for engaging forward and reverse. I know those parts are in the transmission rather than the engine, but lots of people use synthetic tranny fluid, so ....

Anyone have any opinions or better yet facts? (are you out there gsxr1100?)

/forums/images/graemlins/smile.gif

 

[MikePA]

<font color="blue">There has been much discussion here lately about synthetic oils...</font>
Yep, sure has been.

<font color="blue">(all of it interesting) </font>
Depends on your point of view and how many times you've read the same questions and answers. /forums/images/graemlins/tongue.gif

<font color="blue">Anyone have any opinions or better yet facts? </font>
The facts are, 'If the oil (syn or dino) meets the specifications documented in the Owner's Manual it is OK to use.'. I don't understand why people make this more complicated than that. /forums/images/graemlins/confused.gif

 

[ronjhall]

<font color="blue"> The facts are, 'If the oil (syn or dino) meets the specifications documented in the Owner's Manual it is OK to use.'. I don't understand why people make this more complicated than that. </font>
/forums/images/graemlins/blush.gif /forums/images/graemlins/crazy.gif /forums/images/graemlins/grin.gif
Maybe the best answers I have seen. /forums/images/graemlins/cool.gif

 

[JerryG]

The difference in using synthetic and not using them is the additives. If it has the correct additives, it is better. If it doesn't have the correct additives, it shouldn't be used, because of slippage.

 

[sneaky_pete]

</font><font color="blue" class="small">( There has been much discussion here lately about synthetic oils (all of it interesting) and it reminded me of something I heard once. That is that synthetic oils probably shouldn't be used in applications with wet clutches or brakes (those where the friction plates are immersed in oil). The reasoning was that synthetic oil can cause more slippage of the clutch or brake. I'm not sure whether it was supposed to be the base stock or the additives that were "too slippery", but high Moly levels come to mind as something that might have that effect.

When I originally heard this it was in the context of the wet multiplate clutch in CBR600 sportbike I had, but many tractors (including my 990) have wet brakes and many power-reverser type transmissions have dual wet clutches for engaging forward and reverse. I know those parts are in the transmission rather than the engine, but lots of people use synthetic tranny fluid, so ....

Anyone have any opinions or better yet facts? (are you out there gsxr1100?)

/forums/images/graemlins/smile.gif
)</font>

Did you ever try it in your CBR600? Maybe it is brand-specific, or maybe it is just an old wive's tale like the famous "it's too slick for roller bearings, they will skate and not roll".

I use synthetic in all my bikes that have wet clutches (harley, suzuki) and in all my friends bikes that I work on, and have never experienced any slippage at all. It does make shifting smoother though.

 

[gsxr1100]

so you are saying, for example, a group 5 oil is the same as a group 1? when the complete base oil is different, never mind additives;

If you do not want any slippage from clutch plates, use an oil that passes JASO MA cert.

http://www.aac-jasoinfo.com/jaso_web/index.htm

 

[JerryG]

Having the correct additive in the hydraulic fluid is just like putting friction modifier in a positive track axle in a car or truck. You have to do it so that the clutchs won't chatter and to prolong their wear.

 

[gsxr1100]

mostly true..... but the foundation of a dino or hydro cracked vs a synthetic is different from the start.

Plus I might be getting confused since we are talking about engine oil for bikes and tractor fluid here.

 

[JerryG]

<font color="blue"> mostly true..... but the foundation of a dino or hydro cracked vs a synthetic is different from the start.
</font>
They both need the right additives for the clutches.

 

[Dargo]

The owners manual in my Yamaha 660 Rhino specifically states to not use synthetic oil because of the wet clutches. I don't claim to exactly know why, or if it would really hurt, but since the manual specifically address this issue I'll go by what it says. I have no idea if the same applies to other vehicles. I've never seen it specifically addressed until I bought this new Rhino.