i have had a non functioning speedo for over a yr! it would jump around, stay at 0 mph, get stuck randomly...i tried
replacing vss (vehicle speed sensor) and all the grounds, wires, plugs ect.. and nothin! soo instead of having to buy
another cluster i took apart an old cluster i had laying around. on the back of the cluster there r 3 philips head screws
holding the actual speedometer in the cluster. remove them and the entire speedo assembly will fall out. replace ur broken
one with one that u kno works and there u go! it fixed my problem after everything else searching would tell u didnt!

 

werd! this is same thing as swapping the cluster. i've tried everything as well so the only thing left to do is this. kudos man!