The speedometer and odometer on both will not work. Are both my speedo cable and cluster in need of replacing? or is there another problem

Because of the plastic gear on the odometer shaft is some teeth . You'll have to replace the entire speedometer . Or take the vehicle to a shop that does those types of repairs. I went to the junkyard and bought the entire instrument cluster for under 50.00$ . Did it myself. Tedious job don't be in a rush could break something else. .

most old cars have a speedo cable.
is the odometer dead too. (we need that answer now)

there are 3 class evolutionary systems.
cable
electric sender to cluster
and sender to PCM and PCM drives cluster.
but honda does this on diffr, dates than most cars. (i learned)

so lets do that. we login to alldata.com and look , so can you at any time,
once a month i do random cars.
what engine, sometimes this varies by engine, and trans.
neither stated so Ill toss coin each time.
a/t trans.
1996
has electronic (hall) speed sensor VSS and runs
engine, cruise. odometer and cluster.

the 96 has no speedo cable, and works in modern mode, very advance for this time
also any scan tool on earth fits the PCM scan port
and if VSS is dead, it tells you that with a DTC , vss dead.
saving all that work wondering why it dont work.
see/?
PCM must see it work
and cluster
and cruise
if only cluster fails, and both speedo and odometer then its bad.
if only speedo fails but not odometer , then speedo meter is bad.
its that easy.

CLuster speedo and odometer
both dead?
cable. or drive gears in tranny tripped.
easy to check. ?
sure.
at tranny cable free, spin it same direction as speedo needle.
speedo dont work (both odometer and speed) then the cable is bad.
if not work, tranny drive gears to cable stripped out. some are plastic

If the speedo still works but the odometer doesnt then the speedo needs to be replaced, just replace the cluster,

well its usually one in the same. could be the speedo cable or could be the gears in the dash cluster. so either you need a new cable or dash cluster. see if the cable spins then its the dash cluster. check car-part.com for a used one.

it could be the cluster but you have a im put and out put sensor on the transmission that controls the speedo

Is the ODOMETER working? Service eng soon light on? Could be a speed sensor OR a Instrument Cluster problem. If the Odometer works, its an Inst cluster and it wil need to be replaced. Any good Repair shop should be able to get a new one or DORMAN PRODUCTS makes replacement clusters for most GM trucks.

check your speedo cable it runs from your transmission to the back of your gauge cluster. its probleby broken or disconnected

Sounds like either your speedometer cable, your nylon gear on the side of the tranny where the cable ties in, or the odometer itself is shot. One of those three will set you straight. If you are able, remove the cluster, take the cable off the back, and pull it out of the sheath. You will see if its broken or not from there. If not, slide it back into the sheath, then you have to find out where the sheath meets the tranny, and pull it off of there. Then, you can get someone else to watch the speedo as you turn the cable from the bottom. If it works, great, if not, then its your cluster/odometer/speedo. If it does work, the small gear in the transmission is shot.

Since your speedometers work, the problem is in the gearing to the trip and mileage odometers. Simple problem, major pain to fix but, remove instrument cluster - you'll have to remove speedo cable to get it out. Use the old Mark I eyeball to check for broken parts. Might even have to drop steering column - disconnect air bag first!