Serpentine Belt tensioner

[Silversaab]

Hello Gentlemen,
I drive a 2009 S class W221 320cdi.
My drive belt (Serpentine Belt) started to fray today. I checked on line for tools required , bought a belt and got stuck in. Unfortunately my tensioner does not have the normal 17mm Hexagonal bolt to enable me to release the tension on the belt, but instead has a multi face bolt as shown in the photo attached. Does anyone know what type and size of socket fits this. It isnt a Torx so i am at a loss.

Any help would be greatly appreciated as im now without the car.
Regards

 

[Trickythemerc]

You should be able to get a socket on that. I did mine but can't remember what size socket I used .

 

[Silversaab]

Thanks. Ive tried the 17mm and it just started to turn a 16mm wont go on. I'm a little concerned if i damage to much it wont be usable so was going to order the right fitment if i could find what to order. looks a liitle worn to start with !

 

[Trickythemerc]

You will need a double hex, a six point will not do it.

 

[Silversaab]

Thanks. Ive just looked them up and that's exactly what i need . Never heard of them before so thats my lesson for today. Is it a 17mm do you know ?

 

[Wolfie1]

can you not pop i to your local garage and ask 1 of the mechanics for a shot of 2 sockets, maybe leave something with them so they know your coming back

 

[CarFan79]

Thanks. Ive just looked them up and that's exactly what i need . Never heard of them before so thats my lesson for today. Is it a 17mm do you know ?

Yes it's 17mm, I use a swan neck spanner on the tensioner.

 

[Silversaab]

The swan neck spanner worked a treat. It didn't take long yesterday morning. Working in the dark with a torch when your tired is never a recipe for success. A fresh start in the morning with the spanner worked well had the job done quite quickly. Car running well thanks everybody for your input. Regards Silver

 

[CarFan79]

Glad you got it sorted