Hey Steve, I can't PM you, says you cannot receive new messages LOL

I agree with billyT. Mobil 1 is very good stuff, either the 10w-40 or the 0w-40. In my opinion ATF is just too thin when hot to provide smooth gearbox action. Gearbox failure is nearly always bearing wear caused by dirt in the oil or impact damage caused by hitting lever on rocks or poor shifting. I have seen gearbox failures by galling where steel cogs run on steel shafts and ATF has been used rather than the manufacturers recommendation of 10w-40 or light (SAE 75) gear oil.

Cheers

b40rt A dinna ken wit a B40 bike is.

I typed this into google translate for a giggle and it blew up

For a modern bike (1990's onward) I can't see the oil choice being that critical, yet if I had a GasGas Pro I would choose very carefully 'cos an added consideration must take into account that the mains sit in gearbox oil...would ATF suffice? From what I remember ATF is just a low viscosity/high shear hydraulic oil with minimal lubricating properties?

I am willing to be corrected if someone wishes to take this up in detail.

Wayne

I typed this into google translate for a giggle and it blew up

For a modern bike (1990's onward) I can't see the oil choice being that critical, yet if I had a GasGas Pro I would choose very carefully 'cos an added consideration must take into account that the mains sit in gearbox oil...would ATF suffice? From what I remember ATF is just a low viscosity/high shear hydraulic oil with minimal lubricating properties?

I am willing to be corrected if someone wishes to take this up in detail.

Wayne

Seems many run ATF in the Gassers by reports on the threads. I have no specifics, yet once again it does seem to be tougher than one may think.

Whatever Synth and additve properties seem to be good enough with some of the ATF to gat a "fill for life" rating with no service interval. Who's life, I am not sure?

Seems many car engines are nor speced for 5-20w and such as well, for maximum fuel effiency. That stuff is p*** thin as well, but it does work as long as it is clean and fresh!

I typed this into google translate for a giggle and it blew up

I typed giggle into Google translate and a picture of a small girl in a pink dress and pig tails came up !

There is a lot of misunderstanding about ATF. As John Stoodley points out there are some you can use and some you should not.

Putting it simply there is the old fashioned Dexron II, which is basically a SAE 10 monograde mineral oil with antifoaming additives so it works in the hydraulics that actuate gear changes in automatic car gearboxes.

Next is Dexron III which has some multigrade properties but is still approximately SAE 10. It has higher film strength and gives better fuel consumption than Dexron II.

The "newest" ATF is synthetic and designed for sealed for life automatic gearboxes. It is usually designated LT followed by about a 5 digit number.

Car autoboxes are significantly different to trials bike gearboxes and are cushioned by fluid flywheels, jurid couplings, regulated clutch engagement etc.

Why put ATF which is designed for such application in your trials bike gearbox? Surely far better to use Mobil 10W-40 which is specially formulated for the job. If you fancy something cheaper but still better than ATF try universal tractor oil which is designed for gears and wet clutches.

Cheers