I have over 1/2 a gallon of 75/90 semi synth gear oil left from my beemer days, not likely to find another use for it. Do you think it would it be usable in my G5 gearbox/final drive ?Â
I would say so - check the service classification matches/exceeds the recommended if you have the handbook.
Ian
Synth may tend to leak past old models’ oil seals … (?)
Only one way to find out of course …
go for it
Thought I might have given ATF a try in mine. Kind of hoping I haven’t.
Anyone want to wager on how this might manifest itself if I have, given that I’m nipping over to the Dutch rally this weekend?
You still worrying about that empty ATF bottle?
Would be inclined to drain and refill for peace of mind, rather than find out the hard way.
Yeah, still worrying - but I guess not quite enough; for better or worse. I would drain but I’d already added some rather expensive molyslip additive. (So how much is a recon box if I’ve got it wrong?
Box will be a lot more than 75cl of oil and some molyslip 
.
Good lord easy enough to find out, stick a thin sticky shaped thing into filler 'ole, pull it out, how runny or not is the oil on it, there’s your answer
PS: also the smell (to quote my factory workshop manual, “if it smells bad then it’s gearbox oil”)
OK well it is quite distinctive anyway