Speedo and odometer?

Yes that could very well be the issue. Here's the instructions on changing your speedometer cable

REMOVAL PROCEDURE

1. Remove the cluster assembly.
2. Unhook the speedometer cable from the heater case.
3. Remove the grommet from the bulkhead.
4. Feed the speedometer cable through the bulkhead.
5. Raise and support the vehicle.
6. Unscrew the speedometer cable (1) from either the transfer case or the transmission.
7. Remove the speedometer cable (1) from either the transfer case or the transmission.
8. Remove the speedometer cable (1) from the clamp.
9. Remove the speedometer cable (1) from the vehicle.

INSTALLATION PROCEDURE

1. Attach the speedometer cable (1) to the clamp.
2. Screw the speedometer cable (1) to the transfer case or the transmission.
3. Lower the vehicle.
4. Feed the speedometer cable (1) through the bulkhead.
5. Install the grommet to the bulkhead.
6. Hook the speedometer cable (1) to the heater case.
7. Install the cluster assembly.

Hi johnariley,

Thank you for the donation.

The problem is most likey caused by a bad connection either at the meter cluster or a bad ground behind the dash, above the fuse box.

I would suggest checking the ground first. When problem occurs, most probably the ground wire has heated up and due to the poor connection, its continuity is affected resulting in the Speedometer not working and the temp gauge to shoot up.

Most probably the tachometer and fuel gauge would be affected as well.