Gearbox fault

I replaced my 1996 4.0 RR engine with a 1998 4.0 RR engine.Ever since I did that I got a Gearbox fault when I start and shut off the SUV.It also doesn't show the P D R etc. on the dash and the button on the shifter doesn't work or light up to what mode its in(sport or normal).Also when I floor the gas it wont kick down a gear to speed up and when the gears do change they shift hard and also when I slow down they shift down hard.Can someone PLEASE HELP ME!!!!

I just recently had the "gearbox fault" come on during very snowy weather. Same exact symptoms as you: the hard shifting, no downshift, starting off in a high gear, no sport / normal modes, no indicator in message center. Also it clunked really loud in reverse, and jumped out of gear coming down a hill. No idea why! Land Rover mech says transfer case chain wears and then can jump a tooth on the gear, resulting in clunking and gearbox fault. It turns out the computer controlled transmission has a "limp home" mode which it goes into when there is a gearbox fault. This is what causes the no downshift and no indicator lights. I have no idea what caused mine--it just happened and was consistent throughout the day--it was perfect before. Some people said the trans was shot. The next day and ever since the fault message is not there and the car runs / shifts / drives identical to when new. Knock on wood. Computer glitch?

Good luck with yours.

Transfer chain, erh, didn't know it had one.. I beleive the only chain is in the main gearbox, this is then connected to the transferbox by normal gears. I could be wrong though as I have never owned or driven an automatic, prefer the manual shift...

Have you checked the cables, again a simple electrical fault could be the cause, check the cable as it enters the gearbox area.