cambolt said:

Well obviously check obvious stuff like fuses, bulbs etc (I don't know how easy bulbs are to get to on defenders) but if that looks alright you can check if your diff lock is engaging or not:
Instructions on bottom of page
Fixing a Land Rover Discovery Stuck Differential Lock or Transfer Case

Click to expand...

I'm sure he's been waiting for that answer with baited breath for the last 3 years!

Have a Defender 110, 1991 with a Roverdrive DX fitted to a LT230 Transfer case, LT 77 gearbox and a Defender 200TDI engine.

However on engaging it keep getting a whine which becomes louder when speed is increased. Checked the spring preload etc, but just cant get rid of the whine.

have you checked the condition of the oil? has it been like it since day1? does it use straight cut gears?

The crunch between 1st and 2nd is likely the syncromesh. My 300Tdi Defender has been doing it since I got it twelve years age (46k miles at the time). It's now done just on 100k miles. The reason mine went early I believe is because it had been used as a parks ranger vehicle and had obviously spent a lot of time crashing between 1st, 2nd and reverse. Within a couple of weeks you'll get used to the engine note and be changing gear without a crunch. Personally I'm saving up for a galvanised chassis and when I do the change over I'll be getting the gearbox re-built, but that's a way off yet...