Technical Specs

[ARBTAM]

Well I have looked and searched everywhere but I am struggling to find a list of the different technical specs, especially diff ratios used in the different D3 models/engines. Any help would be greatly appreciated to point me in the right direction.

[loanrangie]

I would think the gear ratios are the same across all variants.

[ARBTAM]

No all the diff ratios are different depending on the motor, the one I can't find is the V6 petrol spec.

[loanrangie]

I take it you need a new diff and found a petrol one, LR barely changed any ratios from county to D2.

[101RRS]

I would think the gear ratios are the same across all variants.

This site selling diffs would indicate there are different ratios for different engined D3s - 3.54, 3.07, 3.73 but none listed for the petrol V6

Land Rover Discovery 3 (https://www.winchestergears.com/land-rover-discovery-3-13-c.asp)

Edit - google is your friend - I just found this site Land Rover Workshop Manuals > LR3/Disco 3 > 205-03 Front Drive Axle Differential > Front Differential Description & Operation > Page 403 (https://workshop-manuals.com/landrover/lr3/205-03_front_drive_axle_differential/front_differential_description__operation/page_403/)

It says:

The front differential is available in three ratios. V8 and V6 petrol engine vehicles use a front differential with a final drive
ratio of 3.73:1 and TdV6 diesel engine vehicles use a final drive ratio of 3.07:1, for vehicles with manual transmission, and
3.54:1 for vehicles with automatic transmission. Changing the number of teeth between the crown -wheel drive gear and

For the rear diff it says
The differential is a conventional design using a hypoid gear layout, similar to the front differential. The open rear
differential is available in three ratios. V8 petrol engine vehicles use a differential with a final drive ratio of 3.73:1, V6
petrol engine vehicles use a differential with a final drive ratio of 3.73:1 and TdV6 engine vehicles use a final drive ratio of
3.54, for vehicles with automatic transmission and 3.07 for vehicles with manual transmission. Changing the number of
teeth between the crown wheel drive gear and pinion gear changes the ratio.

So this indicates that the diff ratio for the 4.0 Petrol V6 is 3.73:1.

I hope this helps

Garry

[ARBTAM]

Thanks Gary much appreciated, I had been Googling for hours but could not find that info. We are going to do a Diff ratio swap with Locker install and it would appear V6 Petrol diffs are more plentiful than anything else.........cant understand why as I thought the V6TD auto was the biggest seller D3.

[veebs]

... We are going to do a Diff ratio swap with Locker install ...

As in, retrofit a diff lock?

I know it's been done before, but keen to hear how you get on with this!

[ARBTAM]

As in, retrofit a diff lock?

I know it's been done before, but keen to hear how you get on with this!

Fitting ARB air lockers. Decided we will go with Auto diesel ratios.

[letherm]

Fitting ARB air lockers.

IIRC this approach was looked at previously on this forum and advised against due to conflict with the terrain response system. Try googling it in the AULRO search box below.

Be careful to check it out first.

Martin

[ARBTAM]

Thanks Martin, I did read a bit of a section on that, but there was never given an explanation why. We could see maybe this being an issue with an auto, but cant see how it could be effected on a manual.