saudiboy

Has anyone encountered this?

I replaced my alternator about 1.5 years ago. I was hearing what I thought was some belt noise and today I got some horrific noise when I engaged the AC. I popped the hood and found that the securing bolt had become unthreaded and had worked its way almost completely out. I’m confident that I made a tight connection when I did the replacement.

Fit1too

You might try a lock washer. I thought mine wasn't tightening correctly when I changed the alternator (for the second time in the AutoZone parking lot), so I went back into the store and got a pack of lock washers and used one. So far, so good.

saudiboy

Did you replace the bolt? My bolt does not extend beyond the threaded housing.

Fit1too

I did not replace the bolt. I was on vacation, and an hour away from our destination when the alternator went out. I replaced it, put the lock washer in place, and continued on to the beach. I checked the bolt a couple of times afterwards, but I actually forgot about it after that until I read your post this evening.

salimshah

If the original set up never failed, then something was missed or not torqued right. The newer bolts with flanged shoulder just need to be torqued to spec.

The only thing special about the alternator is the tensioner+lock needs to loosed last [after pivot and anchor have been loosened and the something in reverse when installing [during install the pivot and anchor bolt need to loosely put together 9with give), tensioned adjusted and locked, then the pivot and anchor need to be torqued. If you do it any other way the tensioner bolt will be toast.

Salim.
PS I have learnt that the hard way.

PorchDawg

Might wish to verify that the threads in the alternator adjusting tab are not stripped. If they are, helicoil or keensert will fix. .Maybe find a 3/4" longer m8 x 1.25 bolt and add a nut behind the alternator? Unsure if the alternator tab will allow a nut to fit in there.
Also address the alternator pivot bolt for tight. If loose, the alternator could rattle around a bit, loosening the adjuster bolt.

PorchDawg

For S&Gs, looking at the alternator. It appears that a lock nut could be utilized on the alt tensioner lockinng bolt that screws into the alternator. Suppose a locknut could be added to the tensioner adjusting bolt as well.
once the alt lock bolt is tight, the tensioner bolt becomes immaterial.

saudiboy

Thanks to all who responded; very helpful ideas. I think a couple things were happening, and all of them were on me.

i started to to get a loud whine on ignition. I loosened the alternator locking bolt, tightened the tensioner bolt and re tightened the alternator locking bolt. The whine is gone and and the alternator appears secure. My guess is that the loose tensioner bolt caused enough wiggle to to allow the locking bolt to work its way out and that the vibration also caused the oil dipstick to unseat, resulting in small evap leak code.