Odometer kaput
 

1980 911 SC euro

I've lost my trip odometer, odometer and my speedo is erratic

I did an engine drop back in 2001 and in the process was "less than elegant" when I disconnected the cable leading into the transmission.

My splice job may be less than perfect

After engine rebuild > install [thanks Dave Rielly] both speedo and odometer functioned ok... but now [last week] I've noticed the odometer doesn't function anymore

thoughts?? :?:

If the speedo works but the odometer doesn't, then the you're getting a signal (electrical or mechanical) from the transmission. Sounds like you broke a gear inside the speedo. They are plastic, so this is not at all uncommon. If the speedo itself didn't work, then I'd suspect the cable.

Kim, I would suspect a broken gear. If you want, I have a spare 85mph from a '81 that you can borrow to test the wires/sending unit. The trip odometer and the speedo are accurate. I replaced it with a 150 mph unit and had it rebuilt by North Hollywood. Cheers, Rich

Kim,

I've had the same issue since I bought the car. Speedo and odo work, but the trip meter dosent. Makes a clicking sound at 0009 and the speedo dosent go past 80. It's most probably a gear.

Dunno if this goes for older 911's, but on the 993 it's an absolute no-no to reset the trip meter while the car is in motion. It strips the gear and requires a rebuild.

RL, I'm sorry to rebut you on this but I am convinced that this is an urban myth.

Jim, I was also told it is an urban myth by the folks at a speedo repair shop. Their explanation: the nylon gears just get old and tired; hence they break. A complete R&R on my speedo was <$150 including shipping. It took about a week to send, get it fixed, and recieve it back.

Now I don't have an excuse. :(
Rich

Well, that's an urban myth I don't care to test. It's easy enough to just remember to reset it before I get moving.

Some times the myth/legend is true, just like in this case. Just because it doesn’t strip every time doesn’t mean it wont And it is the gears or more accurately the little “T” on the side that rotates the numbers. Years ago PP had a “how to” on fixing. Really easy, have done it several times myself. Biggest PIA is getting the bezel ring off w/out damage.

I had a similar problem when I turned on the lights, it was a grounding problem in the instrument harness. Fixed by running a new wire directly to the speedo as I was too lazy to trouble shoot where the break was.