Thread: Defender gearing question

Specifically no. Most gauges have some kind of a zero adj and more expensive ones have span or range adjustment.
What does it read at idle? Should be 750/850 rpm. Mine came from LR and just dropped right in. No error, D'Zook's was the same item from memory.

Trev.

ok... what year model, what engine, gearbox and transfer case do you have?

Originally Posted by BigJon

How have your tachos been set up? Defenders don't have them ex factory and the only ones I have seen sense off the alternator. I would think there is a huge margin for error if they are not correctly calibrated. My Rangie V8 has the sensor wire on the tacho and I think it is just a guide to engine speed, plus a pretty needle to watch winding its way around the dial .

The Td5s have a tacho available that reads straight off the ECU. Fits neatly instead of the clock. Anther LR part not fitted when it should be.

Regards
Max P

1997 300Tdi R380 Defender, 113,000km
VDO Tacho

I've only had the car 6 weeks, I didn't fit the tacho, but it seems ok, Peak power at just over 2,000rpm, peak torque at 2,700rpm.

I've got a vague feeling the seller might have said something about lower gearing after I bought the car, when I was picking it up.

But I thought those conversions lowered low range, but not high range.

Can anyone tell me what T/Case conversions there are and how these affect low/high range ratios?

80kph is 3,000rpm in 4th. I don't like driving in 5th at anything below 80 and most 80 speed limited areas are not a smooth 80kph, and I don't like backing off and accelerating too much in 5th - for the gearbox's sake.

Try these links for TD5 Tacho, and Q gears.
Ashcroft Transmissions
Web Rover TD5 Tacho

Trev.

I don't think you can adjust the tacho on a TD5, it runs off the ecu apparently? Mine also gets 2500rpm at 100k/h and always sounds like it needs another gear. that's on standard 235/85-16's

Originally Posted by Michael2

1997 300Tdi R380 Defender, 113,000km
VDO Tacho

I've only had the car 6 weeks, I didn't fit the tacho, but it seems ok, Peak power at just over 2,000rpm, peak torque at 2,700rpm.

I've got a vague feeling the seller might have said something about lower gearing after I bought the car, when I was picking it up.

But I thought those conversions lowered low range, but not high range.

Can anyone tell me what T/Case conversions there are and how these affect low/high range ratios?

80kph is 3,000rpm in 4th. I don't like driving in 5th at anything below 80 and most 80 speed limited areas are not a smooth 80kph, and I don't like backing off and accelerating too much in 5th - for the gearbox's sake.

Defender high range is 1.41:1, disco's are 1.22:1, I think rangies are 1.22 but some are closer to 1:1. Some 110 with 2.5 diesel (not Tdi) were 1.67:1 but it is unlikely that anyone would fit the 1.67: gears to yours.

All stock LT230's have 3.32:1 low range. Maxi-drive makes replacement lower low range gears. You will have no doubt about if these are fitted, because they are spur gears (instead of helical), they whine loudly when low range is engaged.

Ashcroft only made a small number of crawler gears before dropping them. Again it is unlikely you have these.

If the previous owner lowered the gearing, and it doesn't have the Maxi-drive low range gears, it is more likely that the diff ratio was changed (probably from 3.54:1 to 4.1:1). This would lower the overall ratio in both low and high range and would be suitable for running larger tyres.

If the diff ratio was changed to 4.1:1, and you would like to restore on highway driveability with stock size tyres on a Defender, then consider fitting an LT230 from a Disco. This should not cost you much if you sell or exchange your Defender LT230 and do the labour youself (not too difficult).

Edit to fix diff ratio.

VDO afternarket tacho's are adjustable. They hook up to the W terminal on the alternator, and as these have differing pulley sizes/speeds, they need to be calibrated for each application. There is a 'pot' inside that is adjusted to get reading correctly. The only accurate way I can think of to set it up is use an optical reading tacho at idle (read off harmonic balancer) and re-calibrate the cockpit tacho. Run engine at various revs (eg. 2000, 3000 RPM) to double check and adjust as needed.