Disco Transfer box?

[Sam Thompson]

Has anyone fitted the above into their Defender? Apparently it will increase the gearing ratio = better fuel economy. Anyone done it? Any thoughts?

 

 

cheers,

 

Sam

[WorcsWuss]

I thought the transfer boxes were the same.... every chance I'm wrong though...

Diffs are quicker in a Disco / RR, that's an easy swap...

[Treewolf]

I sold an ex-Disco2 t-box to a friend with a TD5 Defender last year. He fitted the gears out of it into his t-box (did it that way because it was the kind of Disco box with no difflock) and is delighted with the result.

 

Defenders up to and including the TD5 have a transfer box ratio of 1.4:1

TDCi (Puma 2.4 and 2.2) Defenders, and all Discoverys have 1.2:1

 

Generally fitting is straightforward, but be aware that there are differences in the speedo drive arrrangements (Disco2 I think uses signals from the ABS sensor and has no provision on the output housing for the speedo transducer, however you can swap the Defender one onto the Disco box). Also remember that many Disco2s didn't have the centre difflock fitted - some have the difflock but no linkage, but most don't even have the difflock. It is, however, relatively easy to put the Defender difflock bits on the Disco2 box.

 

Fitting the Disco2 t-box into a Defender is a very popular conversion; the usual problem is finding the Disco t-box since demand usually outweighs supply.

 

The TDCi (puma 2.4 and 2.2) transfer box has the same ratio as the Disco2 box.

[Chris Sheppard]

Until you fit a TDi I wouldn't bother as your TD will find it hard work.

 

I was thinking about a disco box for my 90 a while back and decided that for the extra little bit of MPG, the taller gearing was more of a hindrance as it drives pretty nicely as it is, and you just get used to going a bit slower on the motorway than you would in a "normal" car.

[Shane]

I did it to my defender last year. Works fine. Gearing is higher so initial take-off (as far as it goes in 2.5 diesel defender) is a touch more delicate as I guess it could stall.

Ecomomy better, but you have to plan your gear selection on long hills if you are towing a heavy load.

I never had any regrets - if the gearing is too high for off-road driving I just use low ratios.

If the disco T box is too high in 1st - stop driving up cliffs!

Go for it!

[C.J]

Discovery transfer gears will give you 15% higher gearing and increasing tyre radius from 205/80R16 to 750R16 or 235/85R16 will give you a 10% higher gearing:thumbup1:

[Ty Unnos]

My 200tdi 110 defender has a 1.2 transfer box from a discovery.

 

I am pretty happy with it. It is quieter in all gears and I get good MPG. It cruises at motorway speed without the engine screaming. Low range is the same on both boxes. The downside is it will have less grunt when towing. To compensate I had a bigger intercooler fitted and the engine tweaked.

 

This can be used to work out the different effect tyres, gearbox, transfer box etc have:

 

Ashcroft Transmissions - Ratio Calculator

[tommer9]

High range is taller, low is the same, so pulling away in firt you will require more revs. Other than that it will bolt straight on etc etc.

[david wood]

i had my 2003 defender swopped within 6 months of getting it and its one of the best things i did. keep toying with idea of a chip but my mechanic has chipped his 110 and seems to fry a clutch a year so not too sure.

 

As said above just good gear selection and you are fine, i know with a heavy (maybe a lol overloaded) load its 3rd up the hill between where mother lives and me, nice (legal) load and its 4th up the hill, both mean i maintain 50mph

 

got my box from ashcrofts cause their reputation for quality and support made it a no brainer.

 

Soo much more peaceful on road and will do a nice happy 90 ish or more at full bore - i get scared at 80 on mud terrains though.......... and 65 seems very very nice speed and car is settled at that.

[antipesto]

I thought the transfer boxes were the same.... every chance I'm wrong though...

Diffs are quicker in a Disco / RR, that's an easy swap...

 

If it's a Range Rover, Defender or Discovery diff then it will be 3.54:1 (13 teeth on the pinion and 46 on the crownwheel), series vehicles were 4.7:1 (10 teeth on the pinion and 47 on the crownwheel) but the diff was weaker than the 3.54 having less contact area between the teeth.

Basically;

anything coil sprung is 3.54:1

anything leaf sprung is 4.7:1

With a couple of exceptions - Stage 1 V8's and 101 Forward Control's.

Transfer box ratios are different between defender and discovery or larger wheels/taller profile tyres will help, but check for fouling and put spacers between the bump stops and reduce the steering angle if the tyres are to close to anything