Hey, I have a question and i cannot figure out what is going on.

I have a 1999 Land rover discovery 1. I just returned home after 8 months and of course first thing i want to do is drive my landy... Well, after cranking and putting it in drive there is a chirping sound that wasnt there before. I haver had this problem before and it was the drive shaft.. But i cannot find and problems with either drive shafts. I grease them every time i change the oil (every 2k miles). The U-joints do not seem to be separating either. I do not know what the deal is. The sound only seems to appear when the truck is under load - I.E. ACCELERATING or ROLLING FAST without pressing on the gas. My prop shaft (front) has some movement back and forth out of the t-case - nothing extreme though. The sound sometimes goes away but then comes back. If anyone has any ideas please fill me in! I am wondering if its one of the front axel bearings. The sound defiantly seems to be coming from the front of the vehicle.

 

belt?
a pulley?

Does it change with road speed or engine speed?