Hi all, I had to change my alternator one way clutch pulley on my 1.8T cab this weekend. Symptoms are a rumbly noise when pulling away on low revs, if left it could destroy your engine, I have heard of the pulley coming off the shaft and the belt wrapping around the bottom pulley, and in turn taking out the cam belt and causing major engine damage.

How to rectify:-

Disconnect the battery first.

Then check your pulley is the culprit, use a 17mm spanner on the casting of the tensioner and slip the belt off the alternator. Very carefully put a screwdriver or similar into the alternator on the fins to stop it rotating, grab the pulley in your hand, it should drive one way and slip the other, if it drives both ways or slips both ways, the pulley needs replacing.

First remove the coolant reservoir screw and move the reservoirs to the side, remove the plug connector for more clearance if needed.

Remove the plug connector from the throttle body, remove the 4 Allen head screws and remove the throttle body housing from the inlet manifold. Put it somewhere clean and safe.

remove the 4 Allen head bolts from the alternator, remove the plug connector and the 13mm nut to remove the thicker cable.

Remove the the alternator from the vehicle.

i held the alternator in a vice by the clamp holes. I had previously bought a removal kit from amazon it comes with a spline tool and a star tool for the shaft. I held the shaft still with a breaker bar up against the bench and used a large spanner to turn the spline tool ( normal thread direction) remove the pulley, make sure the washers stay on the shaft, clean the shaft and locate the new pulley. Do up nice and tight, re fit to car and off you go. Should take no longer than an hour including coffee and biscuit break.