Thread: TD5 Defender ratio change

Hi BAuke, yes it is a good thing, BUT you still have to deal with the 2.5litre aspect, even chipped they are basically nowhere near an Isuzu for bottom end

Highway running it'll be excellent, but you may need to turf the 255's or you'd be in 4th on every hill. And you have HEAPS of hills out where you are

Give it a whirl, I reckon it'll be fine, but 1st gear starts when towing up hill, and reversing a trailer etc will need lowrange.

A bit like my 110 will be trying to reverse with a trailer on

I have a 90 to do soon, THEY really need the 1.222:1 change over IMO.

JC

Unfortunatly you'll have to use the clutch harder on 1st high and you'll have to use low range more offen.
How i know? I have a disco td5 manual and tuned with 235/85 16 tyres it revs 2180 at 100km/h,i put 255/85 16 on,revs drop to 2080 at 100km/h,at 3200rpm you travel with 150+ km/h! but the clutch takes a lot of "beating" on take offs from traffic lights,especialy on ascents,so i was considering using a transfer box from a def..
You can use this Ashcroft Transmissions - Ratio Calculator to experiment.
Only R/P change will suit your (and my)needs ,plus that low range will get lower
At this video http://www.youtube.com/watch?v=E9ZaR...yer_embedded#! i was in 2nd gear low,i had to slip the clutch real hard... i didn't want to use 1st low(my mistake)..

do you really need to change Defa gearing when running 255/85/16?

It is only a 4% increase from the stock 235/85/16

I agree with Fatman that R+P is the best way but that would mean a 3.7 and i dont think that anyone makes them.

Fatman is talking Disco and 255/85 are a 15% increase so he would need 4.11

thanks justin another question does a 1996 v8 disco transfer box fit straight in in regards to speedo sensor etc

Originally Posted by Bauke

thanks justin another question does a 1996 v8 disco transfer box fit straight in in regards to speedo sensor etc

Yes, but you'll need to fit the front output housing, as the low range switch needs to be connected to the system, to allow the engine ECU to know it is in low range, and adjusts the throttle response accordingly.

JC