Land Rover Repair: 2000 Discovery chatter when in reverse, warranty coverage, transmission problem

Question
I have a 2000 Discovery II with 80k miles. For the past 6 months it has been intermittently 'chattering' when in reverse. This is difficult to describe, but it almost feels like you are backing up over very small speed bumps - or maybe that you still have the parking brake engaged and are pulling against it. This is most noticeable when the truck is allowed to just idle while moving in reverse, giving it gas seems to stop the problem.
I have not noticed any connection to either the internal or external temperature.
My local mechanic is stumped (partially because the truck will not perform this trick for him). I have a 100k/6 year warranty that expires the end of this month (03/2006). I don't like to take my truck to the dealer unless I know that the service will be covered.
Any help would be greatly appreciated.

Answer
Hi Jon,

you have warranty coverage?  Get it in quick before it expires.

Sounds like a possible transmission problem (reverse gear?) but can't tell from here.  Could also be driveshaft or differential.  All should be covered under warranty.

In this case, you are not sure of coverage.  The only way to find out is to take it into your dealer.  It could save you $1000's of YOUR money.  If its not covered, LR will tell you very quickly.

It is not normal to hear noises while in reverse.  Sounds like a drivetrain problem.

Best of luck,

JohnMc