Why do you need to change it?

Thanks Tom. It's sounds similar to the VW set-up that i am familiar with but the counterholding uses a spline socket. The Ford counterhold socket seems to be a hex 14mm.

On 1/15/2026 at 8:42 PM, anon said:

Why do you need to change it?

There is a slight buzzing sound I am hearing on start-up so I thought I could change the tensioner, idler and alternator pulley in case it is one of the three.

The overrunning alternator pulley (OAP) of the 1.0 EcoBoost locks mechanically in one direction and runs freely in the other.

The OAP on the 1.0 EcoBoost rarely fails. The only failures I have seen were cases where the pulley was permanently locked in both directions and no longer free-wheeling. These faults were discovered only by coincidence when the drive belt was removed to replace a leaking water pump. Apart from the pulley being permanently locked, there were no other indications of a problem.

The alternator bearings usually fail well before the OAP.  

Thank you, that's what I was getting at.

On 1/17/2026 at 5:43 PM, anon said:

Thank you, that's what I was getting at.

On 1/17/2026 at 9:18 AM, JW1982 said:

The overrunning alternator pulley (OAP) of the 1.0 EcoBoost locks mechanically in one direction and runs freely in the other.

The OAP on the 1.0 EcoBoost rarely fails. The only failures I have seen were cases where the pulley was permanently locked in both directions and no longer free-wheeling. These faults were discovered only by coincidence when the drive belt was removed to replace a leaking water pump. Apart from the pulley being permanently locked, there were no other indications of a problem.

The alternator bearings usually fail well before the OAP.  

Thanks. I shall soon replace the belt, idler and tensioner and in the process check the alternator pulley.