Seen it! If your needles move very fast its the cluster. Theyre air guages and normally move slowly given any input signal...Normally your chevy dealership will have an x-change co. they use. If ya pull it your self you can save allittle $. The reman will be updated and have your milage on the odometer. Just plug it in.
Not sure on the 98s but the 2000 s and up have stepper motors controling all the gauges in the cluster and of course the ones gm put in are the lowest quaulity available and usually the first one to go is the speedo but I have also heard of people running out of fuel on the freeway with the gauge showing half a tank.. Do a search on ebay there is a fellow in NY that rebuilds the cluster with new stepper motors(better quality than gm) and recalibrates the gauges then ships it back within a week. Of course gm didn"t issue any recall on these even though they can produce life threatening issues with speed and fuel miss information. If you buy a new cluster from gm today you get the same old crappy steppers that last about 80,000 kms than crap out.
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