2.7LbBelt tensioner adjustment bolt sheared!

2014 2.7 Prerunner 122k

Was trying to adjust the seroentine belt tension when I managed to shear off the head of the adjustment bolt

Thinking I can pull off the tensioner, extract/drill out broken bolt and replace?

Question is: is that adjustment bolt attached to the engine block or other part or is it just part of the tensioner assembly? Looked at diagrams and googled but haven't found a definitive answer.

 

I thought it was self adjusting?
Isn’t the tensioner spring loaded on the 2.7?

I’m not sure what bolt you are talking about?

 

I'd weld a nut to the broken bolt and try to remove it that way before trying the drill it and use an easy out/extractor.

 

Reverse threads??

 

The belt has a good bit of play so I thought that was the bolt you loosen to remove and replace the belt?

Yeah, I did crank it trying to loosen it.

 

yep I think that bolt is reverse threaded so you went the wrong way. For the tensioner you just want to slowly apply force until you have enough play to slip the belt off of one of the idler pulleys. Much easier than trying to slip it off of any of the pulleys that guide the belt. Same goes for installing the new belt. If you jolt the tensioner instead of evenly applying pressure it can damage the self adjusting mechanism.

 

Nahh, Pretty sure that bolt is NOT a bolt.
You use that “bolt” to let tension off the belt to remove and install the belt.

OP, is your tensioner seized or something?

 

oh yeah, I missed the pictures. I remember on older corollas you had to buy a special socket to even apply force to the tensioner. Glad they stopped doing that, although it may have kept this from happening. If you can't loosen the tension you can't shear it.

 

OP, this tensioner is an automatically adjusting tensioner. You can replace this whole part, but if yours is working fine it isn’t really needed. If you need to remove tension you can do it using the pulley/bearing’s bolt which is reverse threaded.

 

Was hearing what sounded like the serpentine belt and since it's been many miles since replacement, was just gonna change it out the procedure is to loosen that particular “bolt” to remove and slip new one on, right?

 

Yeah, but that bolt doesn’t move, the whole tensioner arm will move.
I believe you’ll be turning “Clockwise” to relieve tension on the belt.
Just look at the pulley that rides on the belt, that Pully needs to turn AWAY from the belt.

 

It does appear to be working fine. How exactly does turning the pulley bolt adjust the tension?

 

And that right there is why my dumbass broke it. Was thinking it needed to be loosened. It's just an “anchor point” to move the tensioner. Now I get it.

Looks like removal and weld a stud/bolt head to it would fix it if needed.

Parable of DIy repair.

Thanks for the help everyone!

 

You can't weld to that unless you know how to weld aluminum, best to just replace the tensioner assembly.

 

It won’t, there is a spring in the arm to apply the correct tension. You can put a breaker bar or ratchet on that pulley bolt to release tension from the belt so you can change the belt

 

I ain't welding sh*t but my uncle can. Taking it off seems like an unnecessary hassle. Just to add the piece back. Will just do what @Murphinator suggests. If ain't broke don't fix it and if it’s broke but works perfectly fine, don't fix it.

 

Personally, I would just replace the whole assembly. There is a remote chance that the tensioner may be failing which is causing your belt to be loose. Not sure welding would be strong enough for the next time you have to remove the belt.