It's my guess that you have two separate problems. The speed signal for the cruise comes from a sensor that picks up its signal from the rotating magnet in the speedometer. The odometer is gear driven off the same shaft. The only possibility for a common would be if the magnet came off the shaft or the shaft broke. We have them in stock if that is the case. It can we replaced without complete disassembly.
I just checked with my speedo guy and he says they do break the shafts above the spiral drive for the odometer.
Bosch Master, ASE Master, L1
33 years MB technician