I was driving my 03 discovery in D going about 20 and all of a sudden it stoped going like the tranny gave out. I pulled over and gave it alittle gas and I head a clunk and in put it in limp mode and so i drove it home. now everytime i start it it will go in R and 1st but no other ones unless I give it some gas and then it will give the same clunk and go in to limp mode. I heard it could be the battery or alternater so i replaced the battery and tested the alternator still the same problem. Can i get any help on what it might be? How do I know for sure if it is the xyz switch Or just a shoot tranny?

 

That is not limp mode. How many miles on the truck, when was the tranny last serviced, how mechanical are you and what are the exact fault code numbers?
I would suggest you not start or drive the truck till you can answer these question since what you describe i.e. not electrical, limp mode. but mechanical.

 

It has around 140000, I am not sure when it was last serviced bought the truck about 10000 miles ago and i havnt had it seviced, when I say it makes that clunk nosie it will start flashing the m and s mode lights and go into 3rd gear, it has the three amigos p1590 p0722 and that's the omly code it is thowing, I'm pretty smart when it comes to trucks just not landrover quiet yet.

 

I had true limp mode probably a decade ago that was due to a faulty battery. Mike's right... there was no clunk. Sounds like a serious transmission problem.

 

With your issues and codes, the 722 lack of speed sensor signal, that is where you need to start.
As for the clunk, could be a failing drive shaft.
I would suggest with your mileage you start doing all the past do services if you don't want that Disco to eat you alive.
Might want to read my major service list posted at the top of the D2 section.
Any question get back to us.

 

Thanks guy I'll be sure to check it out, I've found an 04 discovery transmission and transfer case for $800 at a junk yard it has a 30 day warranty I'll probably get that just because the t case. is there any problems with puting that transfercase and transmission in an 03?

 

Should bolt and plug right up.

I would be sure to change the transmission filter and fluid, and check the front and rear seals while you have it in the open air.