final drive ratio change?

jakebrumby · Post by **jakebrumby** » Mon Oct 01, 2012 5:49 pm

how hard is it to change the final drive ratio on a brumby? would like to go to 27 inch tires but its gutless enough already... any suggestions?

thunder039 · Post by **thunder039** » Mon Oct 01, 2012 5:58 pm

two sets of tyres one for off road one for on road will be much easier

tambox · Post by **tambox** » Mon Oct 01, 2012 9:13 pm

Depends on the diff ratio you have now, there are two available to suit the Brumby, either 3.7 or the lower 3.9.
Check, see what you have, 3.7 is more common.
Otherwise $$$$$$$$$$$$$$$$$$$$$$$$$$$ to get a custom 4.1 or 4.4 diff ratio box made, probably in an L series box to give you the best of everything, then fitting it.
Yep two sets of wheels is much easier

jakebrumby · Post by **jakebrumby** » Tue Oct 02, 2012 6:16 pm

yea i will have the two sets once the lift and muddies are done, am just lazy and dont wana change them over all the time

and its the 3.7 im 99% sure

phillatdarwin · Post by **phillatdarwin** » Wed Oct 03, 2012 5:48 pm

I picked up 4.11 drive line last week for a good price it out of a RS mid 90,s

jakebrumby · Post by **jakebrumby** » Sat Oct 06, 2012 5:16 pm

know where i can get one?

YouTube · Post by **El_Freddo** » Wed Oct 10, 2012 7:29 pm

jakebrumby wrote:know where i can get one?

I'd be looking for a 2L foz gearbox - 1.447:1 low range, 4.11 ratio diffs from the factory. But to fit this box you'd need to modify the gearbox crossmember, drop in an EJ or re-house the gearbox in an L series casing (it slots straight in and bolts up to the EA81) and then organise a new tail shaft as well as a custom gearstick levers/setup using either the L series or EJ setup, I'm not sure which one works best or what exactly needs to be done as I've not done it before.

But that gearbox re-casing trick does work - I've got an L series gearbox in EJ casings for my EJ conversion. Venom has an L AWD gearbox in EJ casings as well. It can go the other way too. Thinking about it the late model gearboxes might have a larger bearing on the input shaft, but this can be sorted with a new bearing that fits the outer and inner diametres as required.

Cheers

Bennie

niterida · Post by **niterida** » Wed Oct 10, 2012 8:20 pm

phillatdarwin wrote:I picked up 4.11 drive line last week for a good price it out of a RS mid 90,s

You mean an RS Turbo ? If its a genuine RS then it is 3.9 front diff and 3.54 rear diff (they have a 1.1:1 drop gear in the rear of the gearbox)