Page 1 of 1
Mineral Oil & Clutch Slip: Anyone used Castrol ACT EVO
Posted: Tue Jul 24, 2012 2:10 pm
Author: Tonto
Previous threads have mentioned semi synthetic oil and probable cause for clutch slip. My A4 was running on Castrol GTX with no probs; did an oil change 300 miles ago again using GTX, but this time she started slipping at between 4-5k. So at the weekend did yet another oil change: I used Castrol ACT EVO 10-40 Mineral: states on the marketing bumph "for use in Classic Bikes" - gobsmacked, but it actually fixed it: 100+ miles and no hint of clutch slip.
Not sure if anyone else had used it - but seems to have cured (one of) my A4's gremlins.
Cheers Tim
Posted: Tue Jul 24, 2012 3:14 pm
Author: Eric Frith
Castrol changed the formula for GTX a while back, it used to be SG but not any more.
Silkolene do an SG semi synth for wet clutches, works a treat
Posted: Tue Jul 24, 2012 4:37 pm
Author: kz900B1
Had the same issue with mine using GTX .Now running Rock oil 10-40 part synthetic and it appears ok.
Posted: Wed Jul 25, 2012 9:29 pm
Author: njwmct
Using Castrol Power 1 - 10/40w semi-synthetic (used to be Castrol GPS) in the MK2 with no clutch slip problems - designed for motorcycles that use the same oil for engine, clutch & gearbox.
I would think something like GTX (a basic car oil) is going to get broken down pretty quickly by the gearbox.
Posted: Thu Jul 26, 2012 7:05 am
Author: 750steve
Yup, GTX makes mine slip now too. Used to be JASO-MA rated now its not. Any JASO-MA rated oil will work in a wet clutch bike as it hasn't had friction modifiers added to it
Posted: Thu Jul 26, 2012 7:44 am
Author: Pigford
If an oil needs some extra "modifier" added to it - it can't be
all that 
Just make sure its
motorcycle specific oil and it'll be fine
Posted: Thu Jul 26, 2012 9:59 am
Author: IanM63
I used to know a crazy black guy with a 'Rat' CB200 who ran it on Mazola corn oil!
Not sure if it's still running now though..
