So what are my thoughts on an the Lokka?
Bloody awesome
One thing that put me off getting an auto Lokka was being told to expect heavy steering in 4WD. I'm happy to say that my steering did not feel any heavier. The steering returns to centre more aggressively, but it is not heavier. I was expecting to have to change the way I drive to allow for it, but I found that the only change in my driving was driving slower instead of crashing and bashing. I also left the rear DL off for pretty much the whole City View trip and only turned it on if I needed to.
There is one hill in the play area at City View which Homer made it up in the wet last time there and no one else could get even half way up. So fridge goes first this time, dragging his diff nearly the whole way. Took a while and a bit of forwards and backwards, but he made it. I went up without the rear DL engaged and it just walked up. I only engaged the rear DL for a small step up near the top. I lost traction and came to a stop with wheels just spinning. In the past I would of had given it a few berries to get over it but this time I just engaged the rear DL and Bruce crawled up without any fuss.
Having the front locked shits all over having the rear locked IMHO . A big statement maybe and fuel for Homer and geek and obviously duel locked is the only way to go , but anyone who is cranky with themselves for not ticking the rear DL option should not be disappointed in having a front locked, rear LSD Triton. It would be much better than just a rear locked one IMO. Bruce would go further with the front locked and an open rear than just a rear DL. A bit more testing is needed (at Coffs maybe ), but so far I'm happy as a pig in shit.
So if you want to lock the front, get an auto Lokka. I would class this as the best mod to my Triton so far
How they work from their website
The actual principal of it's operation while easily demonstrated is difficult to explain in writing - but is as follows.
1. LOKKA has only 4 main parts - a pair of Cam and Axle (side) gears for each axle, there are some springs and pins, some have spacers.
2. LOKKA is normally in a fully locked state and only allows differential action by unlocking the unit when the ground driven force acting on a wheel (either during turning or when negotiating obstacles) forces that wheel to turn faster than the other driven wheel.
ie a turning vehicle's wheels actually travel two different paths with the inside wheel turning in one circle while the outside wheel travels in a larger circle, and therefore faster.
3. LOKKA makes use of two distinctly different sets of opposing forces that exist due to its design - one to dynamically couple the gears when engine torque is applied and the other to uncouple the gears when one wheel overruns.
3a. The locking force is applied by the action of the pinion cross shaft acting on a uniquely designed and shaped cam - the more torque that is applied the harder the unit locks.
3b. The unlocking action occurs due to the ramping effect between the low profile ramped teeth which force the cam away from the axle (side gear) eg when an outside wheel turns faster than than an inside wheel when cornering. Power continues to be applied to the inside axle. As the turn is completed and the wheels again rotate at the same speed, the outside lock re-engages.
4. It should be understood that only when there is an external force being applied to a wheel to make it turn faster than the rest of the drive train will LOKKA allow one wheel to differentiate. Slippery surfaces where one wheel would normally break traction in an open diff cause LOKKA to stay locked - even with one or both wheels in the air, LOKKA will remain locked.
and
LOKKA will perform the same as open and LSD differentials when the vehicle is driven under equal traction conditions, ie on road. The LOKKA allows the wheels to "differentiate" around the turn, but reverses the operation in that it transfers the engine torque (hence drive) to the inside wheel, rather than the outside wheel.
I have Easy Select, but I beleive these also work with Super Select. My understanding is that if you have one in a vehicle with Super Select, then it just means you can no longer run on bitumen in 4WD at all.