I had a squeak and skight knocking sound from the A/C compressor. Fixed the compressor but a slight squeak still there. Suspect one of the pulleys is on the way out. I have just found and ordered all three pulleys from Precision Parts for my CRD for under $100 delivered.
They are also available through Repco, Super Cheap, etc
WRANGLER JK
2/07-09 3.8L V6 OHV PETROL
EP101 53032860AA
EP233 04891720AA
2/07-09 2.8L 4CYL DOHC TURBO DIESEL
EP254 68027602AA
EP227 68027603AA
EP101 68027611AB
Part numbers and drawings can be found at
http://www.precisionparts.com.au/epcat.pdf
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