Speedometer cable not staying put

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Mheinle
Posts: 41
Joined: Sun Sep 10, 2023 7:57 pm
Your car is a: 1980 spider

Speedometer cable not staying put

Post by Mheinle »

Hey all,
When I acquired my 1980 spider the speedo was not working. Looking into it I found the collar was not put on correctly so I pulled it off and saw the cable had slid way down into the housing. I grabbed some needle nose and gently pulled the cable back out and fed it into the speedometer and reconnected the collar. A few of the little grippy fingers are broken but it stays on good. After driving it around 5 miles or so the speedo stopped working again. It looks like the cable just slid back into the housing out of the speedometer again. Does anyone have experience with this? I am wondering if there is something on the other end missing that allows the cable to travel in the housing so much.

Thanks!
18Fiatsandcounting
Posts: 3798
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Speedometer cable not staying put

Post by 18Fiatsandcounting »

Mheinle wrote:Does anyone have experience with this?
Occasionally, although I haven't found a definite idea why this happens. The squared off ends of the metal inner cable need to connect into the receptacle at the back of the speedometer gauge as well as into the speedometer drive extension in the rear of the transmission. There is some "spring-y-ness" in the axial length of the cable, and this spring action helps keep the squared off ends properly pushed into the receptacle at both ends. It's possible to get the squared off end not inserted all the way into the transmission end (but with the outer housing looking OK), and then the gauge doesn't work.

The first thing I would do is make sure that the cable and its housing are connected properly at that transmission drive extension, and if that doesn't work, a new speedometer cable is the usual solution.

-Bryan
Mheinle
Posts: 41
Joined: Sun Sep 10, 2023 7:57 pm
Your car is a: 1980 spider

Re: Speedometer cable not staying put

Post by Mheinle »

Thanks Bryan,
I will venture into the tranny side to check that out. I used to have one of these and so I was familiar with the speedo side, but I have not looked into the tranny side. Just trying to avoid buying parts that can be utilized a little longer :)
18Fiatsandcounting
Posts: 3798
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Speedometer cable not staying put

Post by 18Fiatsandcounting »

Unless the inner metal cable is broken, or the exterior sheath is in bad shape, my guess is that you'll be able to work with your existing cable. Sometimes it takes a few tries to get that squared off cable end properly inserted into the speedometer drive gear on the transmission. Frustrating, but it's one of those Fiat quirks.

By the way, I lubricate the metal cable with a thin coating of moly wheel bearing grease or the like. I used to use lithium grease, but it seems to cake up over time so I stopped using it.

-Bryan
Mheinle
Posts: 41
Joined: Sun Sep 10, 2023 7:57 pm
Your car is a: 1980 spider

Re: Speedometer cable not staying put

Post by Mheinle »

Whelp I checked everything out and it looked OK, but then in replacing my brake booster I was able to chew up the Speedo cable well enough to talk myself into replacing it. It is on order but won't be here for a few days.
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