Yz400d dip stick

[Davey Crocket]

The funny thing about "Dexron" auto oil is 40 years ago there wheren't many specialised gear/clutch oils around....we have come along way in 40 years believe it or not.....fact....auto gearboxes have gear sets that are engaged/meshed ALL the time...ie..no "dog box" (that's what a motorbike gearbox is referred to=no syhncromesh, just smash it in....wonder why the "dogs" burr over?). Modern gear oils have a lot of specialised additive packages in them such as "shock proof" to help with the sudden impact of "wacking" 2 gears together (this does not happen in an automatic transmission) as well as additives for the clutch plates for smooth engagement, disengagement and general operation. I think the oil company's know a fare bit more about gearbox operation than the typical "I have always used auto oil in my gearboxes, forks etc" type of bloke....try putting the old 20W50 engine oil in your new car and see how long the motor lasts?. Same goes with new pistons etc we have now....way better than the "old days"....shit, look at the air filter technology, you guy's are just sticking your heads in the sand to save a few bucks. Most of you guys are riding/racing bikes that are hard to get parts for so why would you not give your gearbox the best chance of survival?.

[firko]

We're all entitled to use whatever oil we choose so if ATF works for you that's great. The way I see it, for the amount of money that goes into rebuilding these old engines, I'm not going to go all cheap arse on the oil that goes into them. I've used Motul Transoil 10W/30 in my bikes for years as do most of my mates. I've also used Castrol MTX gearbox oil with no problems in the past.

[Ted]

Fair call but do you guys dump all the oil after every ride day or leave the good stuff in there for 12 months with any or all shavings in it. Methinks best to use ATF and dump after every ride day.

[Davey Crocket]

That's a cheap cop out......of course you still change the oil very regularly.

[firko]

I change oil after every ride, it's as regular a task as oiling and adjusting your chain or cleaning your filter. Spending a paltry $20 a litre on a $1000 engine is minor outlay when you consider what the possible consequences of running dirty oil are. To be clear, I have friends who use ATF in their engines with nary a problem so I've got no objections to using it, even Frank Stanborough, one of the cleverest race engine blokes around reckons ATF is fine.....but still uses quality 10w/30 or 40 engine oil in his own motors.