I was just on my annual longer trip on the car and the odometer was going to flip to 10,000km. I was on the 401, it was approaching 10k and I pulled over to the shoulder to take a picture, however, when I slowed down the odo/trip stopped with the 4 9s half way rolled with the 10000 half way showing (all aligned nicely). It was like watching a kettle boil so I started up again, and continued to drive another 240km over the next 2 days with no change. The speedometer always continued to function perfectly. I reset the trip in case that would help but and it hasn't moved either. I was told by another car guy to tap on the dash while running and it might unstick or dis-lodge the "gears". no luck. Anyways, I just want to get this running again as it is original mileage and I do not want to give any suspicions that I've played with the ODO. Based on what I've found online, I do not think it would be the transducer but...
....looking for thoughts. thanks in advance

 

Right, not the transducer.

You have some sort of mechanical-ish problem with the odometer itself. I reckon any speedometer shop can fix you up. Or, heck, open up the instrument yourself for a look-see. Might be an obvious fix

Cheers
DD

 

Doug, I took the speedo out, need smaller hands, but anyways. I have a haynes manual and my guage is very different, but it helped enough. The manual says that there are two mechanical cables plus electrical connections, but mine only had electrical connections. I was starting to see how to open this thing, disconnected the three wires (not the bulb wires) such that the whole inside became loose, then I realized that the only way in to the mechanical part was to pull the faceplate ring off. Then I happened to notice that the odometer had moved a little as it now read 10,000 even vs half way between 9999 and 10k. So I plugged it back in, drove 2K around the block and all is working as it should, without really doing anything beyond maybe dislodging whatever was causing it to stick and I didn't have to go inside. GREAT!

That being said, I'm curious about the model. I know I have an 84 series 3 VandenPlas. The haynes manual (yes not British) says it covers 1972-1988 Saloon, XJCoupe, XJ12, XJS (75-85), Sovereign, Double Six and 5.343 12-cyclinder, yet none of them have an all electically connected Speedometer (in this manual). 1) Do I have the wrong book or 2) Do I just have to try take as much as I can as an approximation?

 

Now you know why most owners use their Haynes manual under the short leg of a wobbly work bench :-). Too many details left out, too many models covered in one book.

In fairness even the official Jag manuals were not updated very often and don't always mention the various detail changes. Jaguar relied on bulletins to cover lots of that stuff.

The electric speedometers were gradually phased in circa 1983-84. Not all the cars got 'em at the same time.

Cheers
DD