just take it off and take it to your local prop builder, they will rebalance it for about 20 quid, if its out of balance the forces it will generate will eat UJs and in extreme cases box and diff bearings
PRECISION ENGINE SERVICES Engine Reconditioning Tel: 01463 23553748 Seafield Road, Inverness, IV1 1SG Head Skimming, Common Rail Fuel Injection, Pressure Tests, Block Reboring, Crank Grinding, Diesel Fuel Injection, Propshaft Repairs[/b], Gearbox Repairs, Turbochargers. Mail Order Svsnever used em, just a quick search on yell.com