Alternator Mounting Failure

[b.needalman]

The alternator mounting bolt (bottom, pivot point) worn the hole in the gearcase cover so badly that the alternator is no longer stable. Caused the adjustment stud on the alternator to shear off. The spacer that fits over the bolt between the alternator's ears has a longitudinal crack. The alternator just about fell off.

Has anyone else had a similar failure? Any repair suggestions?

 

[DayDreamer41]

Thanks for posting, I guess a closer inspection is required

 

[Stu Jackson]

You used the wrong size bolt.

Alternator Pivot Bolts for M25 Bracket Upgrades:

Careful Engine Inspection & M25 Alternator Pivot Bolts & Tension Nuts

Careful Engine Inspection & M25 Alternator Pivot Bolts & Tension Nuts

c34.org

Please read the links within that thread for more details.

 

[Don Lucas]

Drill out and install a bushing of correct size

 

[Maine Sail]

That's not really a failure of mount/alternator/bracket it is a failure due to an incorrect installation and lack of routine inspection. If you don't provide more information including engine make, model and alternator make, model and amperage it is really not possible to give much guidance..

The correct repair involves removing the timing gear cover and having a machine shop repair it..

 

[chuck anderika]

More than likely the cause is that when the belt was tightened the pivot bolt was not tightened afterwards. The alternator will vibrate and elongate the holes. This is very common on large J180 alternators with two separate pivot mounting ears and separate bolts.