Belt tensioner casing cracked

[culshaw 1]

Hi all, 

I put too much shoulder into my tensioner and didn't see it fouling a bolt and it cracked the case. 

Does it need replacing or is it only serving the arm of releasing the tension to the pulley?

I don't want to put any tension onto the belt if it's going to rip the casing apart and put metal all down the pulleys

[fendervg 29]

Not sure about this tbh - is the tension spring not in the part that is cracked, as that is what you tighten the bolt in to to release it?

If you are stuck, I think I have an old one somewhere that came off my car about 5 years ago - it was still working fine, maybe a little bit noisy at the time - and you could either replace or swap over your pulley and bearing. 

[culshaw 1]

I've got a spare, just wanted to avoid the faff of detaching the pulley and lining it up correct (it's on supercharger mount)

[1xshaunx1 27]

Fact

The bolt in the photo is to release the tension on the belt so you can change the belt/tensioner. It pushes against the raised knuckle of the casting to do the release of spring, obviously you’ve cracked the knuckle base. 

Opinion 
I wouldn’t think you’ll have any problems if you back the bolt off and removed it to put tension back on the belt. I’d then put marks on the tensioner where the cracks end now and keep an eye on if they are getting longer. If they do you have your answer and you’ll have to swap it out. 

[1xshaunx1 27]

Only problem I can see is if it hits the other part of the stop a lot when the engine is running it will finish it off 

[1xshaunx1 27]

Also it’ll be a git to change if it does break

[fla 9]

I just use a spanner on the tensioner itself to release tension.  A bit easier and quicker.  I had the same issue with the lobe breaking off one tensioner - i think its just cast alloy, so not particularly strong