Defender Transfer Case gearing change

[spudboy]

Have got a UK advert in front of me which says:

DOES YOUR DEFENDER REV EXCESSIVELY ON THE MOTORWAY?
If so, you may wish to raise your transfer case gearing by 15% by changing to the Discovery 1.2 gear ratio gears. THis offers a simple cost effective, easy to fit alternative to the overdrive. GBP558 fitted.

Can this be done in Australia just by purchasing the relevant Discovery gears (looks like 3 gear assembly things in their picture)?

If anyone has tried this, does it ruin the acceleration?

Also - I presume your low range ratios would be unchanged.....
Thanks
David

[rangieman]

are you realy worried about acceleration in a defender hope your not serious https://www.aulro.com/afvb/ https://www.aulro.com/afvb/

[spudboy]

Well I've currently got a TDi300 Discovery, and that is not real flash 0-100, so I kinda know what to expect.

I borrowed a TD5 from the local dealer for the weekend and did a couple of hundred KMs in it, and at 110KM/h it felt like it was doing 4000RPM (No tacho so no actual idea, but it was revving high - esp compared to my Disco).

For long distance touring, I would expect to get better milage if the engine is revving 15% less at 110Km/h.

Anyway - if the TC gearing is upped by 15% I would expect the acceleration to decrease by 15%.

Just wondering if anyone here has done this, and how it feels.....

[disconut]

My defender (with tacho), revs at 2500rpm for 100 klm/hr. From memory the DII Disco auto was 2200 rpm at 100 klm/hr.

The link you have is from Ashcroft Transmissions,

http://www.ashcroft-transmissions.co.uk/.

They are Disco gears and affect the high range only. If your Defender is chipped, this would be a good mod. Currently he was out of gear sets when I mailed him in November. The gears are available in Aus through LRA.

Part numbers:
IEH000081 $330
IEH500020 $330
FTC4850 $800

Plus around $500 to fit. (these prices are mates rates).

I think it is cheaper to import them. (Gear Set only £225 new outright )

Trev.

[loanrangie]

Most fender owners are trying to lower their gear ratios not raise them, they would sell them in the uk coz you have to drive so far to get anywhere near any dirt ! Seriously , it would be a real dog if you lost what little acceleration you have now. Only way around it would be the above mentioned disco t/case gears and smaller diameter tyres which would defeat the purpose.

[disconut]

Originally posted by loanrangie
Most fender owners are trying to lower their gear ratios not raise them, they would sell them in the uk coz you have to drive so far to get anywhere near any dirt ! Seriously , it would be a real dog if you lost what little acceleration you have now. Only way around it would be the above mentioned disco t/case gears and smaller diameter tyres which would defeat the purpose.

You may want to lower your low range gears for rock crawling, but not the high range. After all you still need to get where you are going, even in Aus.
Can you imagine going to the Gold Coast from Toowoomba @3000 rpm for 100 klms? Not likely!
Best option would be an overdrive unit for the high range box.

Trev.

PS I have enough torque to pull higher gears, but it will never make a drag racer. Its just perfect as is for towing, so I am leaving mine as is.

[George130]

I have the ZF auto so do 2200 rpm at 100. I also have rock crawler low range 8) . It would be worth getting an overdrive or changing the high range just for the comfort factor. I just want the new 6 speed auto :twisted:

[spudboy]

Disconut: Are you sure it's doing a "real" 2500RPM at 100Km/h? Is it still on standard tyres?

My 300TDi Disco is revving at 2600RPM at 100Km/h (from memory), so I would be very surprised if the Defender was revving slower. I'll check the revs later today when I go out and about, but I'm thinking that perhaps your tacho may not be calibrated 100%.

Has anyone else got a RPM @ 100Km/h figure?

Maybe it all just sounds louder in a Defender because of the lack of noise insulation.

[spudboy]

Also (Disconut), forgot to say thanks for those part numbers and prices.

I'll be filing those away in my list of useful information for future use.

[drover81]

I've got the Ascroft gears sitting in a box in my cupboard at home. After customs gets hold of the gears and charges GST etc, the end price is close to AU$900 to get them in.

I've just got to find the time to put them in :? This'll be the first big job I've got to undertake when the weather cools down.... Apparently it's a cinche once the transfer box is out...

[rmp]

My Defender does I think 2800 @ 100. Pretty high. But I soundproofed it so it's not so bad. Roll on the six-speed manual :-)

[disconut]

Originally posted by spudboy
Disconut: Are you sure it's doing a "real" 2500RPM at 100Km/h? Is it still on standard tyres?

My 300TDi Disco is revving at 2600RPM at 100Km/h (from memory), so I would be very surprised if the Defender was revving slower. I'll check the revs later today when I go out and about, but I'm thinking that perhaps your tacho may not be calibrated 100%.

Has anyone else got a RPM @ 100Km/h figure?

Maybe it all just sounds louder in a Defender because of the lack of noise insulation.

it real. I run standard tyres. My2003 TD5 Extreme could be different to your 300 TDi.

Ask Zook for his rpm @ 100klms.

Trev.

[spudboy]

I just checked the Disco, and it is 2400RPM not 2600RPM at 100, so perhaps 2500RPM in a Defender is accurate after all.
From my test drive though, it seemed much higher. Dunno why.