defender transfer box

[mattyme]

i seem to remember talk of fitting a 300tdi defender transfer box when fitting 33" tyres.
ive fitted 2857516 tyres to my 300tdi discovery, that equate to more or less a 33" tyre... do i need a defender transfer box?

[ChrisW70]

I fitted a 1.4 transfer box with 265/75s, makes driving around town much easier, can drop into 5th around 35 with no struggling. On the motorway it feels like it could do with a 6th gear, revs up to about 3.5k at 70, more comfortable cruising around 60 and easier on the pocket!
All depends on your driving style and what roads you spend most of your time on

[lambert]

Just be aware that low range remains unaltered between both boxes so off road the overall ratio is still higher than standard.

[Budgie]

You only need a defender transfer box if the road manners are poor.
I changed mine years ago after a trip back from the Belgium National, I was on the M6 with head wind, going up a long but not really steep hill and there was just not power to keep the Disco going. I was being passed by 18 wheelers and ended up in 3rd with my foot to the floor to maintain 40 mph.
That's when I decided I needed to change the transfer box.

After the change it was like driving the Disco on 235's again. No struggling up hills, I could use 5th again at 30 mph (instead of 3rd) and it just made driving it much easier. OK, downhill decents were a little faster than you may want but you adjust your driving.

There is another option though, you can keep the Disco transfer box and change the diff ratios. This has the advantage of changing both Hi & Lo ratio and works out cheaper if you do the work yourself.
You can get the Ring & Pinions from Ashcrofts.