Major odometer troubles...Please Help

[porsche4life]

Recently my odometer stopped working and I assumed it was the plastic gear...I took it all apart only to discover the gear was new and appeared as if it had been replaced by the p/o...So I replaced the speedometer/circuit board/motor combination and that seemed to fix it for about 20 miles...
Therefore my question is has anyone else experienced this and did I just get a bad replacement or do I have a shorted wire or something else bad that is killing the odometer?

[badjones]

Hi there. Two questions. Have you tried operating the speedo while apart to check if the gear is simply slipping on the shaft. Can be done with a battery drill and suitable drive arrangement in the chuck. While spinning watch the shaft and gear closely and make sure their movement is linked. Secondly, I dont suppose the odometer is stuck while about to roll around another thousand or ten thousand miles? I bought my car with the odometer stopped on 12999 miles. When I checked the gear the shaft was turning but the gear wasn't. Turns out the previous owner had removed the odometer wheels and reassembled them incorrectly meshed and it was not possible for the wheels to roll over to 13000 miles. Nice work ay...Was fun trying to get it working again and yes, it was reassembled at 13000. Car came from a well respected home supposedly. I'm sure there are some Aussies from the eastern states will recognise my car and know the previous owner. Hope he stumbles over this message, and thinks about it. Previous registration number was YUX543 (ACT plates).

[porsche4life]

The speedo works when in the car and i know the gears aren't stuck because it worked correctly for about 20 miles...i am fairly sure that the electric motor that drives the odometer or the circuit board one is bad and i really think that there is a short somewhere else causing it to go bad...Nice car by the way i envy that euro bumper

[darth510]

i had this on my 924-easy to fix.
1. remove the speddometer from the car
2.you need to remove the glass from the front and the speedo dial and needle , the outer rim on the front has to be 'peeled off'-see photo

3 with the front all removed remove the cable bit from the rear(2 screews) and the 2 retaining screws, the inners or the speedo should remove now.

The common fault is the bar that goes through the odometer(top set of numbers) not gripping, you have to remove the little red cog on the end and pust the pin/bar out with a nail or small bar so all the cogs don't fall out. Once out burr up the bar to make it rough, i used a small stone wheel in my drill, and put a little bit of super glue on it to make it rough as well, popped it back in and has not let me down at all-the hardest part is removing and refitting the speedo, and by the sounds of it you know how to take the speedo aprt, good luck and let me know if you need any more info on it.

[porsche4life]

Its not a problem with the gear its is good shape and not slipping..there seems to be an electrical problem that is killing the electric motor that drives to odometer

[darth510]

there is no electrical feed to the odometer, it is driven from the speedo cable through a series of cogs, ending up at the red cog on the odometer,the red cog and bar turn-it slips inside the odometer, which is connected to the trip, very common fault on these, heres a link i found that i used to fix mine from the Porsche club great britain.
My odometer no longer records mileage, can I fix it?

A common fault. There is a small gear that gets off line or gets broken/cracks. Second hand units are of course prone to the same fault so it is worth repairing the existing unit.

One solution is to contact Eric Kirk, he is able to fix the unit and his phone number is 01993 882350. He lives in Oxfordshire directly opposite the Porsche Festival venue at Eynsham Hall near North Leigh.
If you contact him please mention Geoff Ives name or else he might be reluctant to talk. His phone number is (+44)01993 882350 (information from Geoff Ives)

The second solution is a home fix. Use the unthreaded end of two 5mm nutserts (A nutsert is like a threaded pop rivet) which are a perfect size to cut off and press over the split boss with some cyanoacrylate (superglue) as insurance.
You drill a hole the size of the o.d. of the nutsert, slightly countersink it and screw the nutsert onto the threaded mandrell of the pliers and insert into the hole. Squeezing the handles together pulls the threaded section forward, and swages the body of the nutsert out so that it grips in the hole. A bolt can then be screwed into the hole. If you buy two, cut off the threaded portion and use the hollow part of it. (Information John Barnett aka 924nutter)

[darth510]

the above info i found confusing, but i rang the guy who explained it, very simple mate, takes 10 minutes,worth a go

[porsche4life]

What year if car is that on?

I have had it all apart once and it is ALL run electrically no mechanical cables involved there is an electric motor that drives to odometer and it is going bad or the circuit that controls it is going bad the gear between the electric motor and the odometer is fine and not slipping at all

I am fairly certain there is a short somewhere that is causing the motor or circuit board to go bad and was wondering id anyone knew what would cause this.

[darth510]

on a 1984 mate, not sure about the newer speedo that are electrically driven. I will have a look around on the UK forums and get back to you if i find anything. Good luck

[p-talk]

Thanks, this really helped me on my odo issues. I had fixed the outside gear a month ago, but that only lasted seven miles . Just finished 'burring' up the bar that goes through the gears lastnight, and finished the speedo assembly this morning. Drove it fifty miles today, worked great - thank!

Originally Posted by darth510

i had this on my 924-easy to fix.
1. remove the speddometer from the car
2.you need to remove the glass from the front and the speedo dial and needle , the outer rim on the front has to be 'peeled off'-see photo

(*image clipped*)

3 with the front all removed remove the cable bit from the rear(2 screews) and the 2 retaining screws, the inners or the speedo should remove now.

The common fault is the bar that goes through the odometer(top set of numbers) not gripping, you have to remove the little red cog on the end and pust the pin/bar out with a nail or small bar so all the cogs don't fall out. Once out burr up the bar to make it rough, i used a small stone wheel in my drill, and put a little bit of super glue on it to make it rough as well, popped it back in and has not let me down at all-the hardest part is removing and refitting the speedo, and by the sounds of it you know how to take the speedo aprt, good luck and let me know if you need any more info on it.

[darth510]

Glad i could help, so many people rush out and buy a second hand speedo which probably will go wrong anyway, when as you know it is a simple home repair.

[Zero10]

The late ones are electrical, and the signal goes through one of those 3 connectors on the back.
First step when you have any cluster issues on a late car is to remove the cluster and clean ALL electrical contacts with rubbing alcohol or a suitable cleaner, then try to clean the inside of the connectors they mate to.

My speedometer was non-functional as well, turns out if you get one of the connectors (lhs vertical one I think?...) part-way on, i.e. one side is latched and the other side clicked but didn't latch, the speedo won't work but everything else will.

I had the same issue, chased it for weeks before I found it was just a dirty connection. Strange because mine just dropped to 0 one day on the highway when it started.

[porsche4life]

Speedo works just fine the odometer quit and i replaced the circuit board that runs it and the new board fried after 19 miles which leads me to beleive that i have a short somewhere between the sender the ecu and the gauge cluster...

[ronin]

what made you conclude that the new board is fried?

[porsche4life]

It could be something else but I highly doubt it due to the fact that it quit that quickly...and the gear is in perfect shape...the combination of the two leads me to beleive that the board is fried just like it was last time....

[ronin]

just as a note: I have seen several odos that needed new gears even though the ones in them looked o.k. they don't need to have a stripped tooth, or other such easily-visible problem, to be defective. just last week, I repaired an odo with a seemingly normal gear that was indeed defective. if you still have the new gear, give that a try first before you declare the new cb doa and go out on a needless wild-goose chase

[tumi]

Hi guys!

The magic of internet ... I'm writing from the south of France, where my 924S has an odometer failure. The thing is just in front of me (the odo, not the 924) on my desk, and I'm wondering wether or not I dare disconnect the needle ...
I'm a bit afraid to experiment troubles calibrating the speedometer afterward?

Anybody got some advice?

Thanks anyway

Tumi

[p-talk]

I was able to fix mine w/out removing the needle, which was good as I had no interest in recalibrating it. I'd try to do the repair first, and only remove the needle if you HAVE to.

Originally Posted by tumi

Hi guys!

The magic of internet ... I'm writing from the south of France, where my 924S has an odometer failure. The thing is just in front of me (the odo, not the 924) on my desk, and I'm wondering wether or not I dare disconnect the needle ...
I'm a bit afraid to experiment troubles calibrating the speedometer afterward?

Anybody got some advice?

Thanks anyway

Tumi