Cracked alternator housing
06-16-2008, 11:10 PM
#1
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Cracked alternator housing
The alternator on my 87 cab seems to have failed. Upon removing the unit I discovered two of the four support blades in the alternator housing have cracked. Is this a common failure? Can it be welded or am I looking for a used unit?
Thanks,
Bob
Thanks,
Bob
06-17-2008, 05:47 AM
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Burning Brakes
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I have this crack, my friends have this crack, and many thread on here talked about it, so I think it's common enought. After reading many thread, I think weld or not to weld is still a debate. If you decided to weld, please post result... after driving for several months?
06-27-2008, 02:14 PM
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There was a post on Pelican of someone in the Dallas area who successfully welded the housing. These are magnesium and can not be welded by just anybody. Don't know the cost or the source, I just remembered seeing the post.
Good luck Bob,
Henry
Good luck Bob,
Henry
06-27-2008, 04:34 PM
#4
Yes, indeed very common.
Aftermarket housings have issues and used ones will eventually crack.
A Pelican, RUSNAK is developing a Billet Housing replacement. Not sure where he is with it but he will keep the Pelicans posted on this.
Aftermarket housings have issues and used ones will eventually crack.
A Pelican, RUSNAK is developing a Billet Housing replacement. Not sure where he is with it but he will keep the Pelicans posted on this.
07-06-2008, 01:25 AM
#5
Instructor
Bob,
DO get this corrected ASAP! I went through a very similar discovery process: an unrelated issue required that I remove the alternator and BANG! I found two of the four supports on the alternator/fan housing completely (in my case) 'cracked' through.
Remember, these four 'supports' are all that hold the alternator & engine fan in 'true' alignment with the housing (we're talking a few millimeters clearance here between the fan blades and the inner surface of the housing itself) and ALSO have to hold up to the tension placed on that assembly by the fanbelt.
With two supports weakend a failure of the other two or even a momentary 'flex' of the assembly at any RPM (especially a high one) could result in a VERY impressive and expensive deconstruction of the assembly and it's surrounding area! Just imagine your entire alternator suddenly becoming a 'free particle' at approximately 6500 RPM indicated!
Not trying to sound too dramatic but I truly hope you get this worked out before the car goes back on the road. I ended up sourcing a used replacement that had NO cracks and after a true alternator failure several years later I was pleased to discover I'd made a good purchase - no cracks.
Yes, it does happen. Why? I'd suspect balance issues, fanbelt adjustment issues or just plain metal/vibration fatique. It's really an imperfect world... some folks see this problem and some folks don't but EVERYONE should be looking for it! Glad you were!!!
I can't chime in on the welding issue and that was one of your main questions. I'd go with a GOOD replacement and then check it a year or two down the road. I don't mean to be an 'alarmist' but a weak alternator/fan support can lead to some tremendous damage if it ever lets go!
Barry
DO get this corrected ASAP! I went through a very similar discovery process: an unrelated issue required that I remove the alternator and BANG! I found two of the four supports on the alternator/fan housing completely (in my case) 'cracked' through.
Remember, these four 'supports' are all that hold the alternator & engine fan in 'true' alignment with the housing (we're talking a few millimeters clearance here between the fan blades and the inner surface of the housing itself) and ALSO have to hold up to the tension placed on that assembly by the fanbelt.
With two supports weakend a failure of the other two or even a momentary 'flex' of the assembly at any RPM (especially a high one) could result in a VERY impressive and expensive deconstruction of the assembly and it's surrounding area! Just imagine your entire alternator suddenly becoming a 'free particle' at approximately 6500 RPM indicated!
Not trying to sound too dramatic but I truly hope you get this worked out before the car goes back on the road. I ended up sourcing a used replacement that had NO cracks and after a true alternator failure several years later I was pleased to discover I'd made a good purchase - no cracks.
Yes, it does happen. Why? I'd suspect balance issues, fanbelt adjustment issues or just plain metal/vibration fatique. It's really an imperfect world... some folks see this problem and some folks don't but EVERYONE should be looking for it! Glad you were!!!
I can't chime in on the welding issue and that was one of your main questions. I'd go with a GOOD replacement and then check it a year or two down the road. I don't mean to be an 'alarmist' but a weak alternator/fan support can lead to some tremendous damage if it ever lets go!
Barry
