Help: Speedometer needle pointing straight down? - 1988
 

Hey guys. Drove the car (1988) around for a bit and after about 15 mins or so the needle just went to pointing straight down. The odometer is working fine. Has anyone else experienced this? I'm guessing it's the speedometer and not the cable. Any of your thoughts are appreciated. Thanks!

Did the needle bounce around before this happened?

It did for a minute or two before it went straight down. But prior to that no. I replaced the cable about 5 or so years ago because it was chattering and dancing around. Bought the one sold by late model restoration.

My first thought is the anti slosh chip in the back of the instrument cluster but I wouldn't bet on it. Either way you are probably going to have to pull the cluster.

Pull the speedo gear and see if it's stripped or if the cable turns freely with a cordless drill.

I don't think it can be the slosh chip as for the speedo is 100% mechanical.

Something has failed internally. The speedometer needle is driven by a magnet spinning inside of it. The needle doesn't physically touch anything and isn't driven by a gear. The gears inside of the unit determine the rpm of the magnet which in turn tells you the mph. It is possible that magnet has messed up. You can take the whole cluster apart without messing up anything to inspect the unit. You'll need to blow apart the cluster down to each gauge set.