The difference between the LR4 and the new Defender is that Land Rover has made it clear the new Defender is targeted at the off road segment, unlike the LR4. True, there is not much aftermarket yet, but what company has been able to get ahold of one? That’s just starting now and there will be an explosion. With the positive reviews it’s received on trips like the one LR did in Namibia, unless it falls on its face in terms of reliability it will be one of the greats in terms of off road vehicles.G'day Joseph Michael, ARB did make an aftermarket rear air-locker for the LR4, but had so many problems with fitting them to the last couple of years of D4. They then dropped the unit & said it was not suitable for D4. ARB's front air-locker works o.k. on D4's, but without a rear locker it's of questionable value. Another Aussie company; Harrop make a brilliant E-locker, based (I believer) on the Eaton unit,
however it will not fit the D4's diff housing. I've tried to convince them to re-engineer their unit to make it suitable for D4 (and D5) but they're not interested even though the market for such a unit is expanding due to D4's becoming a little more affordable here on the used market.
You cannot fit a LR rear diff lock to an existing vehicle as it must be factory-built-in to the terrain system electronics. From this forum I recall that a couple of guys in the U.S. have successfully fitted them, but
maybe they're engineering & electronics geniuses. Dealers can't & won't do it.
I could not imagine that new Defender would be any different. Maybe contact Harrop to see if they've looked at Defenders diff housing specs.
Here in Oz I don't expect to see many new Defenders in the Bush as they're much too expensive with the
packages. The current Toyota Landcruiser 200 series & Toyota 79's are more affordable & Toyota has
dealers even in more remote parts of our vast land that can fix them - unlike Land Rover!!
If you really want a Defender that can handle every terrain imaginable then bite the bullet & pay the price
for a package with rear diff lock. I won't be - my D4 with its terrain system, Compo wheels & KO2 tires
& good protection gear can get me in and OUT of anywhere I want to go - AND it's bigger than Defender
& has a full chassis that can take all the aftermarket gear anyone could possibly need - unlike Defender.