Land Rover Repair: transfer case, limited slip differential, differential locks


Question
QUESTION: I have a 2000 disco 2 and noticed my rear axle not pulling.
I jacked up the front and put it on stands with the rear still on the ground, put it in drive and nothing out of the rear. should have started to push off the stands right? same results in all gears and also low and high range. also on gravel put it in gear and gave it alot of gas just to turn over the tires to see which tires turned over and only the front ones turned over, rear nothing. PLEASE HELP! THANKS>

ANSWER: Contrary to what you believe, no help is needed.  Your vehicle is acting as it should.

Cars have differentials in the axles to allow the wheels to turn at different speeds as they follow different paths around sharp turns.  One result of that is this:  If you jack up one sid eof a regular car's axle, the jacked wheel will spinfreely and the car won't move.  That's the same thing you see when one wheel is spinning on ice and the other side is on solid ground, and you're stuck.

Land Rovers have those differentials in both front and rear axles, but they also have a differential between front and rear.  The result:  Jack up the front, and the front spins and the truck sits still.

But when all four wheels are on the ground, the differentials allow power to be distributed evenly to all the wheels.

Some Land Rovers have differential locks to lock the front-rear system for off road or mud driving.  However, your models does not have that feature.

Best of luck to you!

John Elder Robison

Check out my car blog at http://robisonservice.blogspot.com


---------- FOLLOW-UP ----------

QUESTION: so if this the case, i should be able to jack up the rear and the front won't pull but the rear should spin correct. also atleast shouldnt one wheel pull on each axle in four wheel drive? "a limited slip differential" or does this model not do that? there should be two wheels pulling all the time correct? one on front one on back? or will it just pull on front and not back or back not front. Ive never heard of a four wheel drive with limited slip diff's not turn atleast one wheel per axle before.

Answer
If you were on a steep hill, and you lifted one wheel into the air, that wheel would spin and the others would sit still.  That's the result of your three differentials in action.

Now, as a practical matter, things are not that bad tractionwise.  First of all, even though the differentials are free like I told you there is enough friction in the system that the other wheels will pull you though on that to some extent.

Second, most Discoveries have electronic traction control, which applies the brakes to a slipping wheel, causing the power to be transferred to the other wheels that have grip.

Finally, if yo have become insecure about this, you can purchase a kit to mechanically lock the transfer case front to rear (like a Defender or older Discovery) and then you will have guaranteed drive to both axles.