I used the Amsoil stuff in my last 850R, and that was fine - I used the cooler line method on that one too. As Forrest says, it is a lovely colour
I've been using Fuchs ATF4000 in my 940 and that has also been fine - I chose Fuchs this time as the Amsoil stuff is ridiculously expensive now !
https://www.opieoils.co.uk/p-1052-am...eries-atf.aspx
One quart is just under 1 litre, and I typically run 10-12 litres through when doing a cooler line change...
https://www.opieoils.co.uk/p-965-fuc...ion-fluid.aspx
BTW, my 'take' on the drop'n'refill vs cooler line method is this:
If the fluid is black, that discolouring is likely due to debris from worn clutch plates as much as discolouring due to overheating. That debris is compensating for the clutch plates being worn - its passing between the clutch plates and assisting the friction between the plates, so if you then remove all the debris (using the cooler line method of fluid change), then all of a sudden that assistance is removed and the gearbox fails. This, I believe, is where all the doom n gloom reputation of gearboxes faling after using this methd comes from.
Using the drain and refill method still removes some of the debris, maybe about a third at each change, but as there is still a significant amount of debris in the system, the gearbox continues to work, albeit at a reduced efficiency I'd guess. The gearbox is still knackered, but its struggling along lol.
That is my very unscientific and totally unproven belief anyway