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

Drops the revs 20%, is a good thing for highway use BUT can be a nuisance towing heavy items off the mark, especially up inclines.

JC

Originally Posted by scampo

hi all have just brought a 110 2001 td5 extreme .has any one put a disco transfercase in to one? been told this drops the rpm bye 1000rpm .th vehicle has a power chip up date and goes to good most off my use is highway travel ,i find the sweet spot for the engine revs is at about 90/95 km ,have owned 2 x 130 300tdis over the last 9 years & noticed the same lower gearing rev sweet spot . my ex has a 2000 td5 disco with standard small wheels my guess is there is a a defernent ratio change ?? any help with any sagestions ////?????
all so why are all the defenders ive owned the spedos are out ?? with correct tyres on them .
cheers scampo

A drop of 1000 rpm? Er... not quite. Well, only if you could get to about 5000rpm in a gear, you'd drop back to about 4000rpm in the same gear with disco t/case! about 20% drop as JC said is correct. Many people have done it though.

As for the speedo, I think you'll find most vehicles over-read the speed for a few %, with standard tyres in my D1 the speedo over-read by about 4%, now with slightly larger tyres it is almost spot on compared to GPS. I don't think its a bad thing, it gives a little safety margin if your speed creeps up a bit - you have 2 easy options, fit slightly larger tyres and it will be closer to correct, or just accept driving a few k's slower than indicated and enjoy the view!

As a side note to speedo's over-reading, post 2000 (IIRC) the ADR's were changed such that a vehicle must not UNDER-read the speed, it may only OVER-read by up to 10%, so car makers most likely factored a small under-reading margin to ensure legality.

Seano

hey guys cheers for info was told to expect 15% drop but not the flashest for heavy toeing in top gear .has any one had first hand expierience on this mod .doing the the jobs not the isue its the actual how it went// goes in the long run .not interested in big tyres just interest better fuel or a nice cruise at 110/120ks on the open road & what would be the best disco to score one from ie..manul auto 4or 5 speed etc. just
done a nearly 2000ks trip toeing a big loaded up trailer with 25 / 30 knot head wind and my good it dont even notice it on the back except for the hi fuel witch i expected.
as for the spedo my 130 tdi has 235/85 16s is 101km @110 & 110 defender is 103/4 @ 110 km & my last 130 was 10 k out seems odd
have come across a cheap wreck 130 2000model was thinkin of gradeing tdi to td5 is there a market for 300tdi s gearboxs diffs etc

If you are towing big loads then leave it be, BUT if a one off then yes by all reports it improves fuel economy and you loose that feeling of wringing that wonderful Td5's neck when overtaking at 120

Also, if you do tow you can lope along in 4th gear, which is better for the trans anyway.

ANY LT230 from a Disco will fit, manual or auto. If getting one from a D2 however, mid 2001 to 2003 they lost the CDL etc. This is no biggy as you can rob all the bits from your present case, but that would render it unsaleable....

JC

I went the other way and replaced the D2 Discovery tcase with a defender as I wanted lower torque. Fuel economy suffers, though with larger tyres it improved low down high range. Could swapping tyre size be an easier alternative to the final ratio? Just a thought.

pm Tusker, I'm pretty sure he runs 1.2 high range, but I think he did this when the transfer was apart rather than swapping out the transfer.

cheers not into big tyres thats not my thing may be 20 years ago .plus when remote travling i stay common har har .as you were saying d2 cases just strip n swap gears i see a late modle one in here some where for $300 .as 4 ringing its neck out not constant for hundreds off ks non stop. but i must say im inpressed at what it does

Originally Posted by scampo

cheers not into big tyres thats not my thing may be 20 years ago .plus when remote travling i stay common har har .as you were saying d2 cases just strip n swap gears i see a late modle one in here some where for $300 .as 4 ringing its neck out not constant for hundreds off ks non stop. but i must say im inpressed at what it does

Sure thing, they do a hell of a good job for 2.5 litres!!!

JC