Recently when driving my DeLorean the speedometer needle started to bounce and eventually stopped working altogether. After an internet search I discovered the culprit is usually an issue with the lower Speedo cable and workings. As this non working speedometer will prevent my next W.O.F. from passing it was important to have the problem solved quickly.
My first job was to find the cause of the problem, the easiest way to test the Speedo is to simulate turning the wheel by disconnecting one of the Speedo cables and connecting the cable into a power drill. The Speedo cable connects to the front left wheel through the angle drive; you will need to remove the front left wheel to diagnose the problem. I obtained a cordless drill, and connected the inner cable in the drill’s chuck. By spinning the drill in reverse and having a friend observe the Speedo needle, if registering a steady speed with the drill operating, this proves that everything above the drill is working.
I started with unscrewing the lower end of the Speedo cable from the angle drive, and then connecting the cable flexible shaft end to the power drill running in reverse. With this working fine, I reconnected the cable to the angle drive and tested the Speedo cable beneath the dust shield. Ensure the dust shield fits tightly in the front hub; if the dust shield is very loose then it should be replaced. Make sure the small square drive hole that the cable attaches to is still square and that the square drive spins when the shaft is rotated in either direction. With the dust shield in good condition, I tested the flexible cable shaft that runs through the centre of the stub axle and ran the drill in reverse; this should also show an increase in speed on the speedometer.
At this point there was no reading of the Speedo; this would suggest the fault was between my drill and the rear of the angle drive. I decided to purchase a new angle drive, but also a new dust shield and lower Speedo cable, as I figure these are also getting old and will need replacing in time, these are also cheaper when purchase in a kit as I did (http://store.delorean.com/p-10369-speedo-drive-kit.aspx).
With a spanner I replaced the broken angle drive located behind the stub axle; you will notice that the angle drive has a large nut attached to the back. This needs to be removed, cleaned and reinstalled on the new angle drive. To remove the nut, use a small flat screwdriver to compress the snap ring and remove the nut. After cleaning, install the nut on the new angle drive with the new snap ring. From behind the stub axle, feed the new angle drive flexible cable shaft through the centre in the same manner as the original was removed.
Replacement is reasonably straight forward, although it does take a degree of mechanical skill, knowledge, and the correct tools. This is helped with the detailed ‘Angle Drive Installation’ instructions included when purchased via DMC.
