I purchased my 245 with a non functioning odomer. It’s a very common failure with the 240’s so I was not really expecting to find one with a working odometer. My car did come with service records which indicate the odometer quit working early 2004 at 210,878 miles. I’m not too concerned with the fact that the car possibly has 40,000 more on it since then. I wanted a functioning odometer to be able to keep track of fuel economy. The odometer drive gear had to be replaced to bring the odometer back to a functioning status.
The speedometer on my 245 is electronic. A speed sensor in the rear differential sends a signal to the speedometer which drives a motor to indicate speed and also a stepper motor that drives the odometer. The speedometer itself hardly ever fails and will continue to properly indicate speed although the odometer does not work. The stepper motor on the odometer drives a gear reduction before turning the numbers on the odometer. A small gear in the reduction softens over time and eventually breaks a tooth. Once a tooth breaks on the gear the odometer becomes uncoupled with the stepper motor and the odometer fails to operate. This writing will document the steps taken to replace a broken odometer gear.
First, you need to order a new gear. I purchased mine from http://www.odometergears.com/volvo.html. 86-91 240’s use the 25 tooth gear. 92-93’s use the 26 tooth gear.
First, the cluster is removed from the vehicle. I did not document this photographically. To remove the cluster from the car you need to remove the panels to the left and right of the cluster, the headlight/dimmer panel on the left and the two plastic square panels on the right. They just snap in/out of the dash. You need to remove the knobs before removing the panel on the left. Removing the panels will expose the 4 screws (two on either side) you need to remove to extract the cluster. Once the 4 screws are removed the cluster can be moved out of the dash and unplugged from the rear. Once the cluster is unplugged it can be removed.
When you have the cluster on the bench, you need to remove the screws that retain the cluster to the bezel. They’re the 7 screws that span the perimeter of the circuit board, and the corner of the tach/clock module.
Once you have cluster removed from the bezel you can remove the spedo module. To do this you must unscrew the speedo module from the cluster. There’s 4 screws on the back of the cluster that retains the speedo:
Once the speedo screws are removed, the speedo may take a little bit of effort to remove. I ended up lighly pushing on the speedo sensor plug and the black lever on the other side of the plug, the speedo popped right out:
Remove the two flat blade screws and lift up on the motor. The circuit board is gluded to the motor so they both come up together. The board does not completely detach from the speedo because there’s wires soldered to the board. Just lift the board and motor up enough to expose the odometer gear:
The small gear is stripped. On my speedo, the gear seemed like it was glued down. My theory is that the solvents used in the grease from the factory deteriorate the plastic in the gear over time and soften it up to the point where it fails. When you remove your gear odds are it’s soft as clay. The small gear can be removed from the larger one. Time to bust out the new gear:
Once the new gear is installed the stepper motor can be re-installed in the same manner it was removed. Once the odometer motor is re-installed you’re ready to place the speedo back into the cluster and re-assemble the cluster. When installing the speedo back into the cluster pay close attention to the four electical pins that connect to the speedo. It’s very easy to misalign these pins and install the speedo without them connecting. If this happens, the odometer still won’t work.
Once you have the cluster and bezel reassembled, you can install the cluster back in the car and enjoy a working speedo!