I have the same vehicle and had the same symptoms. At very low speeds when pulling away I was getting a churr rather than a chirrup but as the speed increased or if applying acceleration in the 20 to 40 mph range then it was a chirrup. (What a good word to describe the noise) Because we couldn't identify where the noise was coming from (I thought front offside, my daughter in the front passenger seat thought front nearside and my son in the boot thought it came from the back axle) I chalk marked the front tyres and had someone walk alongside while I set off from a standstill. The churr wasn't associated with the rotation of the wheel i.e. it didn't chur when the mark was in the same place. I suppose I could have researched the differential ratios and done some mathematic but it seemed easier to thoroughly grease both the front and rear prop shaft universal joints. The nipples are on the joints adjacent to the front diff and next to the rear of the transfer box. I also greased the nipple on the rear shaft until the rubber boot started to exude fairly dry stuff and then fresh grease. The sophisticated looking universal joint gizmo on the front shaft next to the transfer box doesn't seem to have a nipple so I just ladled grease into it as best I could. The end result is that I have been churr and chirrup less for the last week and I suspect I may have solved my particular problem. Best of luck.
Thanks John366 it turned out to be the double universal joint at the front. Too far gone to rescue, probably because it can't be greased, but at least I know what I have to deal with now. Sourced a complete shaft from the breakers for £75. Should be fitted by the weekend. Fingers crossed.
Glad to have helped. Mine stopped chirruping for about 300 miles and then started again. As we were on holiday I just pushed what grease was still in the coupling around and back into the coupling and the problem stopped. About 200 miles on it has started again so I'm about to take the front prop shaft off and see if I can strip it down, grease and reassemble it. Otherwise I'm off to the breakers tomorrow. Why Landrover didn't see fit to provide a couple of grease nipples on it is beyond me. despite being eleven years old my Discovery has only done 58k miles so it seems a bit of an oversight.
And having removed the front prop shaft I discover that the part of the Carden joint assembly that is attached to the shaft is broken - the casting has fractured around the cross piece ends. So I'm off for a look at the local breakers too. I see there is a kit on e-Bay for £65 which provides three new greasable cross pieces and the funny gizmo that sits inside the assembly so I think I shall go down that route and fix it once and for all.
