Thread: defender transfercase gear ratio change.swap with disco t/c

I have not driven a td5 defender before, but my manual D2 running 265/75 which is about the same as 235/75, I find it an absolute pain to drive around town and in some cases offroad too. Sure it does drop the revs at a 100 down to about 2200rpm, but its a pain to take off, especially on steep inclines as mentioned. And wouldn't a d2 transfer in a fender throw out the speedo as well? My speedo is out by about 10%. I myself have considered dropping in a defender transfer, bit cheaper than 4.11's.

I have done the complete opposite. My D1 has 30.5" tyres and it was absolutely woeful on all but a flat highway. It would not tow, would not pull away on any incline, had no acceleration. Defenders are a 32" tyre. You're in for a world of pain downgrading to disco gearing.
I've spent the last 2 weeks on a drive from Brisbane to Melbourne and return. It will sit on 120 all day on flat to mild country. It is a small engine, it needs rpm. It does not have the capacity lope along at low rpm. TD5 are more powerful granted but torque is still limited, they are still only 2.5L

if you want to swap im looking at puting a defender case in my disco i would evan pay for the swap

Originally Posted by 100I

I have done the complete opposite. My D1 has 30.5" tyres and it was absolutely woeful on all but a flat highway. It would not tow, would not pull away on any incline, had no acceleration. Defenders are a 32" tyre. You're in for a world of pain downgrading to disco gearing.
I've spent the last 2 weeks on a drive from Brisbane to Melbourne and return. It will sit on 120 all day on flat to mild country. It is a small engine, it needs rpm. It does not have the capacity lope along at low rpm. TD5 are more powerful granted but torque is still limited, they are still only 2.5L

i think their may be something wrong with yours mine has 31's and i tow over 3 ton regularly but didnt find much diffrence apart from 100to 160kmph (privet road tests)

The TD5 130 we recently bought and built up had a Disco transfer case, as we found out late in the build.

As part of the build we installed a flashable chipped ECU.

On the trip to the Northern Territory (Sydney to Gove) , we found we were driving outside the desired rev range and optimum turbo curve, making the drive less than pleasurable. As said in a previous post, 5th gear was really an overdrive, but who really wants to be cruising at 110kms per hour in 4th gear.

Added to that the fuel economy was a lot worse than it should have been.

We did have a decent head wind added into the mix, making 5th gear pretty useless for some of the trip. Also making this worse were the larger than standard tyres.

I drive this stretch twice a year with, lately with a non chipped 06 TD5 Defender and prior to that in a non chipped TD5 Disco and IMHO this is a far better driving experience for both accelleration at speed, general driving, those small inclines, starting on a hill and Fuel economy.

One of my jobs on the 130 is to change back the transfer gear ratio to standard.

My Isuzu 110 has the 1:1 TC (Factory fit) but i've swapped out an R380 into it. (was LT85) Its great on the Highway - but too fast.. I'm constantly overtaking people as the engine wants to be at a bit higher revs.

Sounds great but traveling at 120km/h in a 20 year old car with drum brakes isn't my idea of fun. (or the people in front of me, haha)

Stepping down to 1.2:1 and fitting 33s at the same time should drop me about (licks finger and holds up in the air) 10%, which will put 5th in the sweet spot at 110km/h.

My Father has an '02 fender (Td5, R380, 1.4:1 TC, 235/85) and has fitted the GKN overdrive. This is a really sweet setup. On the highway you just pop a switch and the noise disappears.. get to a hill, flick it again and you power up the hill. Its very very nice - but I can't fit it in my 110 as the Isuzu will eat it.

For a Td5 however, this is the best of both worlds. (albeit more expensive)

F

Hi Scampo, I have a 2000 TD5 Extreme which i have put a 1.2 transfer case into from a 96 Auto 300tdi Disco and i get between 9.2 - 9.8km's per 100k's. Conversion is straight forward enough, i just swapped my speedo transducer and hand brake from my defender t/case over to the disco t/case. My defender is chipped,bigger intercooler,exhaust 2.5in all the way and 18psi boost. I have no problems with driveability at take off and around town driving is far better in my opinion as it uses the torque i have available far better than the old 1.4 t/case. At 100km/h i am doing slightly under 2200rpm, have no problems overtaking from 85-90km/h in 5th and i can tow my 4.5m boat without a problem. I definately wouldn't do the conversion on a std td5.

My issue now is i want to go from 265/75/16 tyre to 315/75/16 tyre and i think this will knock the wind out of its sails. But if you keep the standard size tyre then i think you would be very happy with the end result.

A GKN overdrive would have been my first choice but as they are no longer available the disco transfer case was the next best thing.

Cheers Shane

all sounds good haven't cone the or wont do the bigger inter cooler or the exhaust i don't that will make much more power ,power is very very good if not to much as is .it reminds me off riding a motor bike with a power band have scored a transfer case from this site for $300 from an 2002 disc with 13000km? this ain't got the lock up ,so i should be straightforward to put the gears in to my case ,the works not the problem I'm a mechanic harha was told just swap the gears ,,is this all the gears or just input from gearbox out put and center gear only .haven't done or seen inside off both together.& at the end off the day if its not what I'm after i can reverse it haven't much to loose ,i don't think my 130 tdi would have the top end power for this thou??
+ i dont whant to put big tyres on its dont do it for me
cheers guys

Originally Posted by Bundalene

Also making this worse were the larger than standard tyres.

And that's the biggest problem with converting the transfer case. If you go to a bigger tyre/rim combination you'll hate it very quickly.