Thread: Who's Running a Defender Transfer Case in a Disco Tdi300?

Anyone out there that has done this at all???

AFAIA high ratio remains the same low ratio is lower otherwise same box

Yeah, I thought it was the opposite. There's a lot of Defender Drivers who put the Disco T'fer into their Defenders to obtain a Hwy cruising speed whereas I'm looking for the opposite to counteract the taller tyres I'm running....

rob

Originally Posted by Robmacca

Yeah, I thought it was the opposite. There's a lot of Defender Drivers who put the Disco T'fer into their Defenders to obtain a Hwy cruising speed whereas I'm looking for the opposite to counteract the taller tyres I'm running....

rob

You are correct, the Disco and the Defender LT230s have different high range ratios (Disco 1.222:1 and Defender 1.410:1)


There are two ways to change the ratio:

• as you suggested, replace the entire LT230 transfer case. Mind you, there are a couple of variations out there and I am not 100% sure how compatible/interchangable they are. I think, you will have to change the rear output flange at least.
• you can get yourself a gear set (high range cog & intermediate cluster) and put it into your box and inspect and recondition seals and bearings at the same time. A professional should be able to do the job in eight hours drive in drive out (that's what I was charged).

Just make sure that you do your ratio calculations to see where this change gets your engine RPM wise.

Bought a 200tdi Disco a while ago with the Defender 1.4 hi range (and maxidrive low range). Its still unregestered, but seemed to get along (inc hills) ok when i drove it home. Its on 265/70-16's atm.

I know it's not the question you asked but what about a Bigger turbo? Exhaust mods? More power = better towing capability

Originally Posted by Lemo

I know it's not the question you asked but what about a Bigger turbo? Exhaust mods? More power = better towing capability

All good but the trouble is bigger tyres change the gearing and if the revs are to low as is mine even with a canned 4.6 now that I know it's high range I will be changing it over as well

Originally Posted by jbe

You are correct, the Disco and the Defender LT230s have different high range ratios (Disco 1.222:1 and Defender 1.410:1)


There are two ways to change the ratio:

• as you suggested, replace the entire LT230 transfer case. Mind you, there are a couple of variations out there and I am not 100% sure how compatible/interchangable they are. I think, you will have to change the rear output flange at least.
• you can get yourself a gear set (high range cog & intermediate cluster) and put it into your box and inspect and recondition seals and bearings at the same time. A professional should be able to do the job in eight hours drive in drive out (that's what I was charged).

Just make sure that you do your ratio calculations to see where this change gets your engine RPM wise.

Thanks for that.... I thought the Disco Transfer was a straight swap into a Defender so I thought the reverse would be true as well..... will have to do a bit more research then....

But from a quick calculation, going from a STD Disco tyre size of 235/70/16 to 235/85/16 is a 10% increase in size. Now, going from a Disco T'fer to a Defender T'fer case is about a 15% reduction, so, if my maths is correct, I'd be easily better off doing this mod as it will help on take-off on hills, towing and even may bring me better economy....

The Tacho works off the ALT doesn't it? IF so, then my Tacho will be out, not that it be a big problem and I assume my speedo would be out as well and again, that wouldn't be a big issue for me as I mostly go by my GPS......

Anyone out there that is good with maths and that can tell me if my thinking is correct?