LR electronic 'e' differential
 

Done the usual web trawl but can't find out what exactly land rover's electronic 'e' differential is (on the middle and back of Range Rovers and the like) and how it works.I take it there is no viscous element?

Plenty of RR reviews parrot the blurb but none actually explain - not even LR.com and it hasn't reached Wiki yet.

thanks

Chris S

Chris

The Disco 3 and Range Rover from 07 use Torsen centre diffs (06 and before Rangies use an open Tosen diff)with a clutch plate locker operated by an electric motor -winding the plates tight against each other - so it can be unlocked or fully locked or anywhere in between - (the dash screen only shows it being either open or locked) - depending on the Terrain Response, gear, throttle, engine load, steering positions.

The rear Diff lock works with a clutch system again - operated with an electric motor - fully locked to open and anywhere in between.

they both work very well - as you climb a hill even before you get any wheel spin the CDL engages (engine/gearbox load sensors) and the rear will lock up instantly when TC kicks in - or when you engage Rock Crawl/Sand.

The transmission (ZF Auto) system is the best ive used - it will go places id struggle to put my 90.

- we asked the engineers when we first got them if there was an exposed bolt head on the Torsen/rear diff you could manually operate with a spanner to lock/unlock if the electric motor went u/s - 'nope' was the answer - and that puts me off using one in remote areas - that and the rest of the electrical gubbins and the fact that it weighs 2.7 tonnes (kerb)......1 ton heaver than a 90 hardtop.

the diffs are quite reliable - we dunked them underwater (in silt laden water)daily and had very few problems with them - unlike the handbrake...

cheers
Grif

Thanks Grif.
So these cars dont do the brake spinning wheel Traction Control thing like TD5s.
Had a go in one the other week and I got the feeling stopping/releasing individual spinning wheels would work better than locking a whole axle on and off when going up a steep slippery slope. Better even than a fully locked-out axle diff.

Ch

Yes I've heard about the handbrake. I read one bloke got through 4 before he got a new car. The people on the TD5 day were getting a new Freelander 2 too after only 3 months. On and on it goes which explains these guys' rationale:
http://www.aroundtheworld1999.com/rovers.htm

no problem Chris,

other way around though - they all have 4 wheel TC a la Disco Td5 - the rear locker is a cost (well worth it) option...

so when the rear diff is locked the TC wont cut in on the rear wheels (as both wheels are turning at the same speed)

The TC is 3rd generation - it cuts in within about 1/8 of a revolution of the wheel spinning - its an excellent system - super fast...

...but the rear locker gives 100% traction (as long as the tyres have grip) with no delay and less ground/tyre damage than TC.

The rear/centre locker will also release some preload on a tight turn so you dont get wind up or make the wheels 'skip'

The only drawback with TC is that you can cook the brake discs/fluid if you are on a low grip surface and the TC is working is nuts off over a long time.

a Rover with a rear locker tackles terrain better than one with just TC - it still has TC up its sleeve to to maximize traction if required (on front wheels especially or if the rear locker is u/s i suppose) and still let you steer.

later
Grif

Very good answer and a full explanation - thanks.

Ch