Land Rover Repair: clunk, balljoint, input gear

Question
Clunk  at down shifting during slow stop and go movement. 98 Disco. 50k miles. Never off road, all dealer service.  Is this gear box mainshaft spline ware?  Cost to repair? Or should the transfere case be replaced?  Thank-you, Kirk

Answer
Hello Kirk,

could the sound also be a balljoint?  Here's what I found out for you:

mainshaft clonk:
The best way of determine the degree of mainshaft wear is to chock the two front wheels, handbrake off, mainbox in first and jack up a rear wheel. Remove the PTO cover to the left of the handbrake and you will be able to see the gearbox mainshaft in the centre and the transfer case input gear around it. By rocking the handbrake drum you will be able to rock the gear around the shaft thus getting some idea of wear/backlash between the two.

Balljoint:
Car in gear with parking brake engaged on a flat surface. One person watches the ball joint and the other rocks the car hard back and forth. You should see movement if it is loose. You can also try moving it with a pry bar.

If you've never had balljoint work done, a 98Disco with 50K miles ...you may want to test this out as the possible cause first.  About 3 hours work and much less in repair bills.  Cost depends on your area.  I had balljoint work done here in Quebec,Canada and it cost me $800.  

If this is a gearbox problem, chances are the dealer will push for a replacement.  Insist on repair or even a rebuild. Transfer cases run about $2000 while rebuild kits can start at $400.  

Good luck,

JohnMc