Ok, can someone please explain the difference between the pre-'04 transfer
case and the '04 onwards one?

What dynamic difference did in make in the behavior of the car. Some people have said that from '04 onwards that the car really doesn't have AWD anymore. Can someone explain what they mean?

Thanks
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Jaguar: Grace, Pace, and Space - Sir William Lyons

 

What people mean is that the viscous coupling was dropped in thre 04 and on transfer cases because they seemed to flex too much. Flexing is why the transfer cases wear out because it causes different wear on the internals. This flexing with the lack of oil in the case causes them to fail thus the reason why the 04 and on reduced the flexing by removing the viscous coupling. Basically the new transfer cases use a different mechanism to transfer power to the front wheels when they slip which doesnt work as well as the old viscous couplings. I bought an 02 for the coupling because I live in colorado and couldn't be happier with it. with that being said, the reliability isn't as good as the 04 and on cases

 

The Post-04 models trade in the viscous coupling for an open differential, and rely on the DSC/ABS to detect wheel slippage and apply the brakes on that wheel. When that happens, power is routed through the open differential to wheels with grip. Post-04 AWD is inferior in ability because of the open differentials ability to transfer power less effectively, and because models without DSC are essentially FWD. Without DSC, ABS cannot detect wheel slip, and without braking that spinning wheel, power cannot be transferred.

It is almost essentially FWD, until wheel slippage occurs, and then it becomes AWD.

 

aml, I never actually knew how that system worked! thanks for describing it, and it makes sense how it wouldn't really work very well. The only thing I would like to add is that I believe that it is exactly how you have described except that it is not fwd bias but instead actually rwd bias. I have seen, heard, and read about how post 04 models are basically rwd.

 

So when I turn off DSC, will that make the car FWD or RWD and save me fuel?

 

It's RWD 59/41% bias to the rear split with power

I was stuck in snow and the rear wheels span like crazy, applied the handbrake, all 4 came into play and out I went.

 

That's what I thought ian. Do you know if the power bias split at all from pre 04 to post 04?