need help with diff locks !!!

I'v just bought a 1991 range rover for off roading, lots of fun but it has no diff lock, it's been converted from a petrol V8 auto to a 200 TDI manual. I'v looked at diff lock kits but are really expensive, i also looked at fitting a disco tranfer box but i don,t know alot about land rovers and if its compatable. Can anyone help point me in the right direction cheers.

If its a 91 you have a viscous coupling.this works like a central diff lock but ovibously isnt switchable. If traction is lost heat is generated in the vc and a jelly substance in there reacts to heat making the central diff locked.its probbaly as good as a standard difflock found in discos and defenders.if you want a locker on an axle then your talking dolla.

yep what g said

i have that in my bobtail and it works well,if i get stuck i have front and rear arb air lockers

i can imagine that the viscous coupling works well cos obviously its like an intelligent diff lock.

the only concerns people have is that it only comes into action after you got wheel spin happening, whereas with a locked diff youve got power transmitted all the time, limiting the chances of getting into a spinning axle situation in the first place.

is it possible that the viscous can send more power one way depending on which axle is spinning? or does it give no more than 50/50?

what about having a quaife centre diff btw? because theyre torque biasing, can they send more power away form the axle that is spinning? now there's a thought

or a pair of arb air lockers

if its a viscous transfer box, check its got ATF in it rather than gear oil. My bobtail transfer box works way better now it has the correct Auto Transmission Fluid in it!!!