Speedometer question
 

Is there any internal maintenance/repair work that can be done to the speedometer? The needle periodically sticks at zero, and I've gotten adept at doing the finger-flick thing on the glass to get it to dislodge. I eased it out of the dash to check for any loose electrical connections, but they're all tight... so the sticky needle appears to be mechanical in nature. It's not like I have to pound on the dash or anything, just a gentle tap on the glass dislodges it. I'm hesitant to disassemble it for fear of springs and stuff flying out. Has anyone encountered/corrected this before?

Don

Don,

I have the EXACT same problem since I acquired the car. I was driving my Mom around the other day and told her that if she borrows the car and the speedo isn't moving, just gently tap the dash above and it will "wake up". I also removed the speedo and all the connections looked good.

Anybody?

Thanks,
George

Send them out to North Hollywood Speedo for rebuilding. Chances are the odometer is going to go soon anyway so you may as well plan for it.

While DIYing the speedo has been done it can turn into a nightmare if you fark up the needle. Just getting the gauge bezel off can drive you mad.

BTW-these are classic symptoms of pending complete failure of the unit so di it before it gets to that point.

Mine did it one year, had it repaired and the next season my tach did the same thing. DOH! Sent that out to a local shp for repair that time.

Be aware that this is sometimes a sender issue, same symptom: needle "still" then swings up to 25 mph or so then works fine. A search will find several threads on cleaning magnets (I believe on the fly wheel) or replacing the sending unit.

what year? mech. cable up to MY 197x, electronic therafter

Thanks to all for chiming in! RWebb, it's an '85, so it's electronic. DublinOH, I'm thinking that a sender issue wouldn't clear with a finger flick to the glass, but anything's possible. Wayne, thanks for the info. I must admit that I was hoping for an "Oh yeah, dude, just snap open the bezel and put a drop of 3-in-1 oil on the movement bearings and you'll be good to go!", but that's like hoping for a divorce lawyer to say that the judge ain't going to hose you over, so I'll look into the North Hollywood place. George, good luck!
Don

I can open and repair mine, I'm sure you can too. You really do just remove the trim ring and the screws and it comes apart. I just got a newer nicer speedo this spring and I wanted to set the miles, so I opened it up and removed the pin for the ODO gears and set it.

The rest is just a simple circuit board, a drive motor for the miles and clock spring and motor for the needle. It just depends on the level of effort you want to put into a DIY.

Don:

I used to work for VDO (the manufacturer of these gauges). The speedo needle stuck at zero is not a sender issue and it is independent from the odometer. I remember the movement used on the speedo and tachometer. In German they are called "Drehspulmesswerk", but I don't know the English word. My speedo does the same thing (I bought the car this January). There is simply a buildup of sticky dirt at the resting position of the movement in the zero position. All it takes is to open the speedo and carefully clean it. Of course getting the bezel off and most important back on is the tricky part. I will drive mine until the winter when I park the car and will do the job then.

Juergen

Thank you Scott for affirming that the disassembly isn't that challenging, und danke schön Herr Juergen. That's the extent of my off the top of my head German, and though the "Drehspulmesswerk" word won't translate in my online translater, but "Bewegung" shows up for "movement".

Without regard to that particular nonsequitur, thanks for the insight. It does seem as though it would be dirt-oriented stickiness, and minor at that, being as how the weak magnetic pull from the winding at 5mph is enough to move the needle from zero after the slightest of finger flicks. I agree that this is a wintertime miniproject, no doubt best attempted with non-shakey hands on a morning when I haven't had ten cups of coffee.

Don

ok, it's electronic, so you do not have a speedo cable that is sticking

what I hear re dis-assembly of VDO speedo in general is to be careful getting the needle off & back on

post pics if you do it

As far as I remember you don't need to take the pointer off to clean the stop position of the movement. The moment you take the pointer off the speedo needs to be re-calibrated. To calibrate the speedo you need special equipment (I think a frequency generator) and you need to know the calibration data. So, don't take the pointer off.

Great, promote another source of repair when Pelican
provides that service, but use the Pelican forum to
get help!

I did not know this. By all means, send it to Pelican for repair if you don't want to DIY.

I had a good transaction with Hollywood Speedo and have passed along their name for several years.

Loren,

Do you have a link to Pelican's speedo rebuilding service - I can't seem to find it and I have exactly the same problem as the op.

Thanks

Rob

Porsche 911 & Carrera Gauges and Miscellaneous - Page 1

Service is mostly for mechanical repair according to the text.

Thanks Scott!

Regards

Rob