Alternator Pulley Failure

[red coulee montana]

Has anyone had experience with the alternator pulley failing for a 1993 GMC 6.5TD X-Cab 4x4 3/4ton. Mine has the single serpentine belt with AC. This is the second pulley I put on which has failed again. Leaving me dead on Rogers Pass in Montana pulling a 40 ft 5th wheel this weekend. Needless to say the pulley is a dealer item and no one within the state of MT had one available. The nice guy at Napa auto parts in Lincoln MT tried to help but I was out of luck.
The alternator comes without a pulley for some reason on this model. I have replaced the last alternator when the pulley failed pulley ruined its shaft.
The pulley breaks right at the nut and washer seat on the alternator itself. I have check all other pulleys for the AC, PS, PB, and tensioners for any drag, but found nothing.
Any ideas or advice would be helpful.

[diesel65]

It sounds like you are missing the spacer that goes behind the pulley and supports it where the nut and washer clamps down.

[Hye]

Around here, the alternator rebuilders have pulleys and will install them correctly. Get the same diameter as the original, or your tach may not read correctly.

I have not had great luck with rebuilt or even OEM alternators. I've learned to change one in fifteen minutes and always keep a "lifetime warranty" spare within reach. There are some spacers required, behind the pulley and on the mounting bracket.

[red coulee montana]

Thank you for the advice. I will look into this further.