Offroad-Express

Toyota Hilux, 2003 mod, 2,5 TD / D4D /SR5 / type KDN 170 / 2WD / 4WD / high / low, no installed switch for rear diff lock activation, no electric locker, no vacuum locker or any other patent is to be observed on the rear differential.
When operated in the 2WD position it is almost like any other car to drive and turn. But when used in 4WD position it is almost like the rear differential is locked, when doing sharp turns the rear wheels lock, and even when car is fully loaded (1000kg wood ) the wheels are syncronius locked, and the car is almost impossible to turn around, at least on paved roads, a little bit easier on earth / moulded ground.There seems to be a kind of differential locker type installed, but the symbol in the instrument panel (RR DIFF LOCK ) is never lit, I have checked the bulb, and it is OK.
Could it be a so called ( LSD ) limited slip differential installed ? Most people think so because there is no locker type to be seen on the rear differential. Driven on paved roads, doing sharp turns ( in 4WD mode ) results in a reacceleration, almost like doing a sharp brake, the rear diff must in one or another way be locked visible lockers or not. But to my knowledge, a LSD should not be so hard locked, or what ?
Anyone know anything about this system ?
Is it a complete rep.manual available for this pickup, I mean except from the original expensive Toyota can offer on DVD ?

Thanks for any answer.
Best Regards
Ronny / Oslo

Unless you have a center diff don't use 4wd on the tarseal or grippy surfaces. You can damage your truck.

This is from a review of your truck "The SR5 is designed to run in 2WD-only on bitumen" so I suspect it does not have a centre diff. Leave it in 2wd on high traction surfaces.

Normally if it's a factory LSD it will have a red/white transfer on the diff housing quoting LSD.
Since its obvious that it's not an E-locker....has someone else (previous owner)installed a lockright?
If you want to find out for sure it's not hard........
Jack both rear wheels off the ground
-spin one wheel, if wheel on opposite side spins opposite direction, open diff.
-if both wheels spin same direction....LSD.
-If both wheels spin same direction( but you can spin one faster than other.... with a ratcheting noise) then lockright installed
good luck