03 Siverado Z71 Speedometer

24K miles on it and noticed that the speedometer was jumping last week and I was passing cars on the highway supposedly going 40mph. This morning is was showing zero at about 30mph. Been searching the net and have seen many owners complaining of the same problem and wanting a recall. Read that this is a cluster problem and that it's likely to be a 500$ repair. Warrenty is expired and the extended warrenty won't cover it. I'd like to call GM and complain and see if they will pay for it. I guess, what I'm asking is how do I go about this. I want to exhaust all avenues before I fork over 500$ which I can't afford right now. I would appreciate any comments/suggestions. Thanks.

Yeah It Seems Like This Is A Pretty Common Problem..Take A Look At This Thread It May Help Ya Out....http://www.automotiveforums.com/vbulletin/showthread.php?t=537373