Diff ratio

[TD50WA]

Hi all
I've recently joined the D3 brigade, a TDV6 2.7.

As I understand it, the diff ratio is 3.54 for the standard tyre size of 30". I have now fitted 31.5 inch tyres (285/60/18) and whilst that is quite ok on those diff ratios, if I have worked it out correctly, the 3.7 ratio out of a V8 would put the overall gearing back to normal.

Will the 3.7 ring and pinion go into the 3.54 diffs? And will they handle the torque?
I am going to retrofit an Ediff so would like to get best ratio for the bigger tyres whilst I'm at it.
Any thoughts ...........info appreciated.
Cheers all
Kev

[SBD4]

Kev, if you are planning to retrofit the e-diff then you will be buying a whole new "e-diff" anyway so the discussion on fitting the 3.7 ring and pinion into the 3.54 housing is moot.

If you haven't yet, have a read of this to get an idea of what you are up for:

Disco3Club The Discovery 3 and 4 Owners Club • View topic - Locking Diff retro-fit (http://www.disco3club.co.uk/phpbb/viewtopic.php?f=9&t=943)

https://landroving.shutterfly.com/1433

[TD50WA]

Yep seen that write up, that's where I got the idea:D

Still have to do the front diff though don't I?......don't think 3.54 at one end and 3.7 at the other will go too well.......:p

Getting the mechanical will be ok, it's the wiring that will be fun. It's just a concept at the moment, I saw an e diff on eBay with the 3.7 ratio, that's what made me think of the ratio change.

Cheers
Kev

[SBD4]

Yep seen that write up, that's where I got the idea:D

Still have to do the front diff though don't I?......don't think 3.54 at one end and 3.7 at the other will go too well.......:p

Getting the mechanical will be ok, it's the wiring that will be fun. It's just a concept at the moment, I saw an e diff on eBay with the 3.7 ratio, that's what made me think of the ratio change.

Cheers
Kev

quite right! wasn't thinking about he front end when I wrote that!

[TD50WA]

Yeah, I knew what you meant though.....:D

[Redback]

If you're going to all this trouble, think about fitting an ARB locker to the front with the 3.7 ratio.

Baz.

[TD50WA]

I have thought about the traditional lockers but I haven't had the car long enough to evaluate its ability. From reading various forums, there appears to be some who like normal lockers and those that say that it is better to let the terrain system work like it should and a locker would interfere with this. As I said, I have no opinion on this because I haven't really looked at it or spoken in depth to anyone that has a locker and what effect if any it has on the cars systems.

[~Rich~]

If you're going to all this trouble, think about fitting an ARB locker to the front with the 3.7 ratio.

Baz.

If I need to rebuild either end that's what I'll be fitting. ;) Got the compressor.
(Standard ratio though)

[jonesy63]

I wonder if unseenone (whom hasn't been here a while) does a kit to do the conversion? As North America have mostly V8s, they should be readily available.

[Tombie]

Do some checking that the vehicle systems will play nice with the ratio change.

The computers may not like the speed variation between gear, road and engine rpm

[TD50WA]

Yes Tombie, someone else suggested that issue as well, so I think it's better to stay with original ratio. Glad I asked though, could have been expensive or even dangerous I guess.
Cheers mate.
Kev