A few weeks ago I went to start my Freelander TD4 and got the dreaded "click-click" when turning the key. This happened at pretty much bang on 110,000 miles, and it's weird that I've fixed several TD4 Denso solenoids at around this mileage. IME at beyond 100,000 miles, the solenoids on the TD4s are on borrowed time.
I was 99% sure that it was the solenoid that was bad, but I still felt the need to go back to basics and check my powers and grounds. These are simple multimeter checks:

• Connect multimeter negative lead to the battery negative terminal and the other end to the post of the heavy lead on the starter. This is hot all the time but check the reading with the key in the crank position. It should be close to battery voltage/crank voltage. If not, the heavy lead is suspect.
• Next, with the multimeter negative lead to the battery negative terminal move the other lead to the thinner control wire on the solenoid. With they key in the crank position this should be close to battery voltage. If not, the problem is with the control side.
• Finally, check the engine block ground. Keep the multimeter negative lead to the battery negative terminal and connect the other lead to a good point on the engine block. With they key in the crank position the voltage reading should be close to zero. If it is not, there's a bad ground.

With those tests done I was now sure that the solenoid was bad so could proceed with the repair. Since I wasn't in the mood to just junk the entire starter motor for a solenoid I scoured eBay for a repair kit. I found one from a company called RepairkitsUK with had the plunger and contacts, and another from NipponNev that had the contacts and insulators (both sellers on eBay). I bought both because they were cheap and wanted to make sure I had all the parts but in the end I could have done the job with just the RepairkitsUK parts.
Now it was time to turn the spanners. There's nothing tricky about removing the starter (an air ratchet does make the job quicker and easier, but it's really not that hard). Then it's just a case of pulling the solenoid apart, replacing the contacts, applying a light coat of grease to the shaft of the plunger (a very light coat), and then putting it all back together.

The beast fired up with just a flick of the key, and it's been great since.
As you can see from the photos, the contacts were pretty crusty, and it would have been a shame to throw the starter away for just a few contacts.
I'm certain that if I didn't have a repair kit that I could have cleaned them up with a file and got the beast moving again for at least a while.

I buy my kits from RepairkitsUK did both my R40 and TD4 in October and a few members since then, not to bad a job to do link below from doing mine, I thought I had posted this on here already but cannot seem to find it.
http://www.the75andztclub.co.uk/forum/showthread.php?t=227316

Got my kit from RepairkitsUK as well; Carl was very helpful when I called him with a question.

Great post BTW, wish it had been up about six weeks ago...

Great info, doing this job tomorrow morning with the RepairkitsUK kit. Two days from ordering to delivery on a remote Orkney Island. Most impressed.

Fairly straightforward job, trickiest bit was slackening the rear retainer bolt on the starter motor. Started first time - good stuff all round. Thanks again.

Ok, back to square one - went to start this morning and back to 'click click click' (although a very resonant click!) Tow started and it's been fine since. Test 1&3 (11.85v/0.00v) check out, but I'm reading 0.01v on the thin lead - even when it starts. Most peculiar. Any ideas/tips/pointers/advice before I start rooting around?

If ok when being used and the engine is warm to normal temp, sounds like it is the starter motor, when the starter is cold all the bits contract, turning a thin contact into an open contact.
Good chance you will get the click click in the morning. Have also known it to be thin contacts in the ignition barrel/starter button

Worked it out - alternator tested a1, as did battery. Hippo wouldn't start again yesterday, checked voltage, was low, charged battery, and she starts. Ergo - battery was discharging somewhere, but slowly. Remembered that the cig socket was corroded, removed it, tested and voilà -continuity between live and earth. New socket on way.