Anyone know what the ratio of a GKN overdrive is?

Also I know that Ashcrofts underdrive is 2.69 ratio but what ratio are the gears in their low ratio transferbox?

Can't seem to find the figures anywhere?

http://www.ashcroft-transmissions.co.uk/contact.html

The info isn't there anynore!

I know, thought maybe those who had one (Nick, Rob???) might know.

JST/Will Warne sent me spread sheets with all the details I can post them onto you later if that helps.
(on a different PC to this one)

That would be great thanks Tony

defender at blueyonder dot co dot uk

I seem to remember the low ratio gears being an 80% reduction, bringing low down to about 5.95:1 ish?

Overdrives seem to bring revs down from 3000 to 2300 at 70mph, which implies a 30% reduction if my maths is vaguely correct?

... or about twice the 'overdrive' of going from 1.4 to 1.2 t-box.

Tried that but excel didn't understand "about twice the 'overdrive' of going from 1.4 to 1.2 t-box"

Worth a read http://forums.lr4x4.com/index.php?showtopic=2785

Thanks Ralph. But still no mention of the actual overdrive ratio, is it a big secret?

Don't think so, But there's no mention of the ratio in my GKN O/D's owners booklet/fitting instructions.

just found this but no mention of ratio at all http://www.gknservice.co.uk/gkn-ids-uk/res...L_Landrover.pdf


at the bottom is a e.mail address, I've spoken to the named guy when my solenoid & speed sensor was playing up, he was most helpful & should know the answer to your question, I haven't found anything about the ratio used.

I have tried google and no mention of it any where I can find. Not essential but would have been a nice to have for a little something I've been playing around with