Replacing a Noisy Speedometer Cable On a 1985 Cadillac Fleetwood Brougham

This customers car has been in my life for way too many years and the last few times I have had the car in for repairs I have noticed and commented to the customer about a very noisy speedometer cable. The customer finally said she has also had enough of the noise and now I get to change it. The original cable was a two piece design and it has been replaced by a one piece design. After looking over the situation I decided the first course of action was to removed the instrument cluster and this started with removing the left vent lever knob. An allen screw holds it in place.

Next I wanted to remove the hidden phillips headed screw in the driver’s left vent assembly.

It is a little tricky and you need a magnet or a magnetic tipped screwdriver to get it out without dropping it down the vent.

Next, I took out the two screws in either corner of the instrument cluster opening.

Now onto the easy screws at the bottom of the dash panel.

Tilt the wheel down, drop the shift lever all the way down and remove the trim panel from the dash.

Disconnected the shift indicator cable at the base of the shifter collar.

Remove the four retaining screws and pull the instrument cluster out. Well it is little bit more complicated than that. The cluster will only come out so far before the speedometer cable and cluster wiring stops it. On this one there was not enough room to access the clips in the rear so I had to go through some extra steps.

I had to remove the wiper and headlight switches and squeeze my hand in far enough to work the wiring around so that the cluster would come out far enough.

With the cluster now out a good two or three inches I had to maneuver my hand gently behind the cluster and squeeze the two harness retaining clips at the ends of the connector. Then with the main wiring loose I could depress the spring lever lock on the back of the instrument cluster to release the cable from the cluster.

Between the pictures above and below I think you can see the design of the clips and retainers for the main harness connection. The picture below has the instrument cluster removed and upside down so you will need to bear in mind that when you reach your hand behind the cluster the connection is at the top left and not the bottom left. Right and left in relation to a vehicle are always from the perspective of sitting in the driver’s seat looking forward unless otherwise noted.

The three wire connector shown is held in place by a single screw. The unit is the pickup of the vehicle speed sensor and it is a photo optic design. Pretty high tech for it’s time. On the other side of the speedometer housing is the spring clip that has to be depressed.


The three wires go back to the VSS sensor assembly. It is the yellow box further back in the dash.

The hole for the speedometer cable is shown below. It is to the right of the brake booster and just above the bulkhead wiring connector in the picture.

The following picture shows the grommet that goes into the firewall. By the way please remember to wrap a piece of mechanics wire around the speedometer cable assembly before you pull it out. It makes it much easier to pull the new cable into its proper position. I forgot because it had been so long since I had done one I guess.

The old cable has been removed. The new cable has been greased with the supplied grease and put in the proper location at the transmission. I did not actually connect it to the transmission until I had everything connected in the dash. Sorry for the lack of pictures.

The above picture shows the lack of a guide or fishing wire as I explained earlier so it took quite a bit of doing to get the cable back into proper position.

Once I had it back in place it was just a matter of reassembling at of the pieces. Several things to remember. Use a guide wire on the cable, remember to hook the shift indicator cable back up, check to make sure the new cable is not kinked, near the exhaust or anything else that may damage it. Lastly connect the cable to the transmission.

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