I have never needed to use my transfer gearbox (I assume that's what it is called per my manual) and am now trying it out. I can't get it to shift. I have had the Disco for 3 years. It is a 97Disco 1. Can you tell me how to do it? There were several ways in the manual, one talking about putting the car in neutral and depressing the foot brake and the ER brake. My ER brake cable is broken. Could that be the problem?

If someone can walk me through the correct process, I will give it a try!

thanks so much!

 

Thank you for including the year and vehicle. It is amazing how many people don not.

If you cannot get it to work with one of the two ways under "Normal Method: Automatic Models" (assuming you have an automatic) as outlined in the manual then the "advanced method" is unlikely to to work either. Setting the parking brake is included just for Land Rover's liability, in case someone is too dumb to hold their foot on the brake.
Since you have no idea how long since it has been engaged, and it's been at least 3 years, the linkage is probably corroded enough to make it not easy to move.
You could try going to a self wash car wash and spraying underneath at the linkage. If that does not work you probably have some work to do.