The odometer on my '85 Carrera just stopped working but the speedometer is still functioning.

I did a search here to find a DIY fix but couldn't find a thread for my all electronic type speed/odometer. I pulled out the unit and I can't see how the front bezel comes off. There are screws on the back but they don't seem to hold the unit together. Is this no cable type of speedometer unit sealed? Should I just put a crowbar in my wallet and send it off to Hollywood Speedometer?

thanks in advance,

 

in the book "101 projects for your 911" there is a chapter on Odometer repair. I would imagine that is cheaper than sending it out.

 

The bezel comes off, but you have to be VERY VERY patient. Use a small screwdriver or knife, start at the biggest gap, and widen it patiently going around the gauge several times. There was a thread on this recently. The replacement odo gear is at Performance Products, or on Pelican.

 

The fix for this is to send it to North Hollywood speedo (no association) and have them replace the plastic gear that went bad with a nylon gear. I had this done a few years back. In fact I sent out all my gauges to them to have them cleaned and had the pointers all replaced with nice new red ones. I also had them re-calibrate the speedo as they all read high..mine was reading 14% high..now its spot on. Turn around was fast and cost me a few hundred sending out all my gauges. Hope this helps

 

I have the "101 things ..." book and it deals with a cable driven speedo with a different bezel than mine which is why I am so tentative about this whole thing. I work on my own car all the time but these delicate electronics make me uneasy. I hate trying to fix something and then breaking something else.

 

Very easy to break something during this repair process...but it can be done successfully.....

for the costs, however,.I'd let NHS handle it....

Doyle

 

Best call....


Doyle

 

Since you're getting a lot of votes advising against DIY, I'll say it can be done, especially if you're patient like rusnak says.

I bought the gear from Zims - cost like $30, which seems like a lot for what you get. It came with a single sheet of installation instructions. One thing the Zims guy said was that they think the problem was with the grease they originally put on the gears. After 20 years, it dissolved the plastic gear to the point where the teeth fell off and it stopped working. From looking it mine, I believe it. Instructions were to be sure to not use any grease on the replacement.

While I was at it, I tweaked the speedo needle slightly to make it more accurate (I'd say "calibrate" but that seems too good a word for what I did). Also cleaned the inside of the glass.

 

I have a 50% success record with this job. I fixed one and broke one. I look at it this way..... buy the gear for $20 and try it yourself. If it works great, if not, you can get a used replacement for $150. The downside is it won't be the original odo and the miles will no doubt be different...... Your call

 

funny story ... not a hijack but not exactly related .. I had the bouncing tach symtom and knew I needed to send it away. So i bought a tach exactly like mine at Hershey for 40.00 so i would have something to use while mine was being shipped away. It worked freakin perfect with no tach bounce whatsoever so now mine is in the spare parts bin ... unloved ....

 

If you sent it to North Hollywood the other day it would already be back in your hands...thats how fast they are at doing this

 

In case it helps anyone, I found the old instructions that came with the gear.File0007.PDF

Skimming over the instructions, I recall one critical thing I did differently. Where it says to pull the speedo needle off "with your fingers (not pliers) ... WE HAVE SEEN THE SHAFT BREAK OFF BEFORE", I first tried to do that, but it seemed to be about to break. Yes, I had reached that critical decision point in many repair projects - what do you do?

I actually took a small pair of needle nose pliers and held the shaft from moving while I gently twisted the speedo needle on the shaft. This was enough to break the stiction, and then I could pull it straight up and off. Prior to removing the gauge, I had figured out how high the speedo was reading at ~60 mph, so when I re-installed it, I factored that slight correction angle in.

 

Iceman....I remember when you scored that tach. I was jealous!!

 

Does anyone here have a copy of the cal procedure for the speedo? As I recall, it requires use of a signal generator.....

That's one good thing about having NHW Speedo do it: you get a proper calibration with instrumentation (not approximating a needle position movement).

I cannot, for the life of me, find this procedure,..I KNOW I have it somewhere........AAARRRGGGHHHH!!!!!!


Doyle

 

I fixed mine by myself. It is really not that hard and I did not have instructions. I don't remember if I had to remove the needle or if I just worked around it which I have done on some cars. I have bought at least 8 gears for different cars from http://odometergears.com/ and I think he is the supplier to all those other companies.