Speedometer issues

[micbrody]

Hi,
I purchased a 1981 5 speed in November. I had posted earlier about bouncing, incorrect speedometer. Most suggested it was speedo cable. In the interim, the speedometer has totally quit (not even inaccurate bouncing). I replace cable without any help. I then diagnosed the problem (with help of 9 y/o handling power drill): The female square connector on back of gauge is stripped/too open to grab the square edges of cable. Unfortunately, with all the connecting and disconnecting, I broke the plastic lock sleeve. I was able to jury-rig it to gauge with a combination of zip ties. I then "tightened" the hole by shoving copper wire, until cable seemed snug in hole. It lasted about two miles ( I am guessing the zip tie thing was marginal). But in that limited time, I observed that speedometer gauge seemed "funky". Not sure if the following is normal with Fiat 2000 gauges but:
1: In reverse, gauge deflected into negative territory. I thought speedometers were geared only to go positive (and though not sure, I think reverse moved the trip odometer (Think Ferris Bueller)
2: Speed seemed off. Gauge seemed to read at least 5-10 MPH faster than I was going.
3: When I came to a stop, the gauge would take another second to actually read zero.

What should my next steps be:
1) Just get new cable; shim the internal female hole; and live with funky speedo
2) get new speedo cable and gauge
3) gearing on tranny speedo screwed up? replace tranny speedo gearing

[124JOE]

I have a spare gauge if you want a used one

[Exit98]

don't drive yourself crazy. Take Joe's. There are tons of old speedos laying around.

That and a new cable and you are good to go.

Just make sure they are compatible. Ask around, I think the later one's are different from the mid year ones or something like that. AR will know when you call for the cable.

[124JOE]

its out of an 80 FI

[micbrody]

I'm thinking of taking u up on the offer. I did see a lot of people in the board like the old style 140mph gauge. My understanding is that it is compatible with existing tranny gear; just the connection on gauge might be different. Any thoughts?

[124JOE]

I can find it when I get home
, then snap a pic to post tomorrow.
yes the face
yes the back
and try for one in the hole

[baltobernie]

All Fiat Spider speedometers have the same internal gearing. What is different are the transmission and rear axle ratios throughout the years. These are matched to the speedo by attaching the correct speedometer gear module to the transmission housing. You can Search the forum on the various combinations available, and how they're color-coded, etc.

BUT ... unless somebody swapped rear ends on your car, the speedometer should be "slightly" optimistic (showing perhaps 63 when you're doing 60), and the odometer should be dead-on, but only if you are running stock-sized tires. Larger or smaller tires will result in errors to the speedo and odo. Google "tire size calculator" to find several sites that will allow you to plug in your tire size vs. 175/78R13 and show you the over/under you can expect. 185/70R13 is a pretty good "modern" equivalent for these calculations.

[azruss]

The early 140 mph gauge is a deep gauge requiring more room than the later shallow gauge. They also take a cable with a threaded sheath connector rather than the plastic thingy.

[RRoller123]

I have to say that I like the 85mph gauge better because the needle is up in the middle of the field for normal operation, easier to read, just seems right. (I never go over 85 anyway, just too wimpy to do so in a 35 year old car I guess)

Pete

[124JOE]

it looks like a 2mm square hole

[micbrody]

Fixed problem. I got new cable; jammed in thin pieces of copper (cut tiny rectanglar sliver from copper strapping) into the extra space between rectangular cable end and receiving hole on speedometer. 30 miles and still working