Alternator Belt problem

[eclpsd1]

I'm looking at purchasing a used 1991 Talon TSI AWD. The current owner says the only problem with the car is that it keeps throwing off the alternator belt. He said he was told it needed a "spacer on the pulley". What would cause this? Is it easily fixable? Thanks in advance for the help.

 

[xcelr8n]

harmonic balancer is probably fubar...

 

[luv2rallye]

No stock pulleys need spacers unless some bracket is really bent in which case you will always have problems. I agree check the harmonic balancer (main pulley) for separation (and wobbling).