Speedometer doesn't work

On my 91 LX 5.0 the speedometer cable jumps all over the place. What should I check? Thanks

Check the speedometer gear located in the rear of the transmission. It's probably chewed up and needs to be replaced.

Check the speedometer gear located in the rear of the transmission. It's probably chewed up and needs to be replaced.

How do I get it out to check it?

Follow your speedo cable to the back of your tranny(drivers side rear of tranny) it will plug into your speedo sensor. Then remove a small bolt holding the speedo sensor into the tranny and pull it out exposing the speedo gear at the end, check for wear. If it needs to be replaced take the retaining clip off and replace make sure you get the right speedo gear depending on what gears you have.