Does your speedometer needle bounce at speed?

[TurboChris]

This has been bugging me forever. My speedometer needle in my 66 Fairlane bounces as much as 10 mph when I'm doing 50-75 on the freeway. The cable was replaced when I swapped in the TKX so I ASSumed it must be the speedo head itself (it also did it with the C6). I removed the cluster and took it into a speedometer shop today and he hooked it up to a tester he has and it was perfectly steady at speeds up past 100.

But

I noticed as he stood there holding my instrument cluster that if he moved slightly it did exhibit some bounce.

What say you all? Does your classic car have much if any bounce at speed?

Video for reference (with the C6 but it's the same with the TKX)
https://youtu.be/OYk7D6QcchY?si=pkiSKUs6VA26G7yk

[frankenfords]

My guess is the cable needs to be lubed. Many companies sell a dry graphite lube in a tube. Pull the cable all the way out of the sheathing, put it back in while applying liberal amounts of the dry graphite, that should solve the problem. If it doesn't, maybe look for kinks or hard bends in the cable and sheathing.

[1964Fastback]

Also I think the inner core will only pull out from the speedometer end, not the transmission end, because of a crimped bead on the top end of the core wire.

Pat

[galaxiex]

Bends in the cable must be large radius and smooth.
No tight bends or kinks.

I've encountered factory cable installations
where using any or some of the factory cable hold down clips,
they put a very mild kink in the cable and cause that kind of bounce.
So mild a kink you would "think" it's ok, but no.

Remove the clip and let the cable find its "natural" position.
Extend the clip somehow to hold the cable in its/that natural position.

This can be tricky if the kink is up under the dash.
Not much room there....

By the same token, a cable that is unsupported and "floating" in space can cause the same issue.
It needs to be restrained, but in natural non kinked way.

[allrightmike]

I've been down this road also and my tip is to pull the driven gear assy. from the transmission and inspect the teeth, also inspect the teeth on the drive gear, all the way around. Don't be surprised to find damaged teeth on one or both.

[475fetoploader]

This has been bugging me forever. My speedometer needle in my 66 Fairlane bounces as much as 10 mph when I'm doing 50-75 on the freeway. The cable was replaced when I swapped in the TKX so I ASSumed it must be the speedo head itself (it also did it with the C6).

How do you like the TKX? Also, what shifter did you wind up with?  I put a TKX in my 67 last weekend, Im shopping shifters, and probably will just build a crossmember.  Thanks for any info

[TurboChris]

New transmission / drive gear.... LOVE the TKX. Total game changer. Where with the C6 and 3.25 rear gear I'd be buzzin at like 3500+ at 75mph on the freeway, now (with 3.89) I'm at like 2500. I ended up with the Tick Performance short shifter. It's a solid piece. We used the C6 crossmember and flipped it.

This has been bugging me forever. My speedometer needle in my 66 Fairlane bounces as much as 10 mph when I'm doing 50-75 on the freeway. The cable was replaced when I swapped in the TKX so I ASSumed it must be the speedo head itself (it also did it with the C6).

How do you like the TKX? Also, what shifter did you wind up with?  I put a TKX in my 67 last weekend, Im shopping shifters, and probably will just build a crossmember.  Thanks for any info

[57ford]

On my 57 Cusom 300 I had the same problem. Look at the back of the speedometer head where the cable attaches. That threaded nipple has a bronze bushing that the cable slides into and a piece fo felt that needs oil. On top of that nipple there should be a small hole to oil that felt. One or two drops of a light oil like 3 in 1 is all it needs. Do not over oil it. It's a bear to do if the speedometer is in the car. Hope this helps.

[TurboChris]

I'll look, thanks!

On my 57 Cusom 300 I had the same problem. Look at the back of the speedometer head where the cable attaches. That threaded nipple has a bronze bushing that the cable slides into and a piece fo felt that needs oil. On top of that nipple there should be a small hole to oil that felt. One or two drops of a light oil like 3 in 1 is all it needs. Do not over oil it. It's a bear to do if the speedometer is in the car. Hope this helps.

[TurboChris]

Ok where does the speedo cable enter the cabin on your Fairlanes? Mine is thru a hole in the floorboard about 12" forward of the left (when you're sitting in the car) front seat mounting location. Then it runs under the carpet up to under the dash.

I'm wondering if it should enter the cabin more forward, like maybe 6-12" under where the steering column passes thru. Might be less constriction and curves that way?

[66FAIRLANE]

Here is what I have found helps. Reach under the dash and unscrew the cable. Get oil on your fingers and quickly reach back under and lube that brass bush as best as possible. Do this a few times. Reconnect the cable BUT do not do it up all the way. You can seat that 'nut' but then back it off a turn or two. This stops/reduces thrust force on that bush. Worked for me.

[galaxiex]

Ok where does the speedo cable enter the cabin on your Fairlanes? Mine is thru a hole in the floorboard about 12" forward of the left (when you're sitting in the car) front seat mounting location. Then it runs under the carpet up to under the dash.

I'm wondering if it should enter the cabin more forward, like maybe 6-12" under where the steering column passes thru. Might be less constriction and curves that way?

Apples to Oranges....

My 66 Galaxie the speedo cable enters thru an oval hole just to the left of,
and slightly behind, where your right heel would be with that foot on the gas pedal.
There is a "channel" depression in the floor and toe board to accommodate the cable,
as it makes its way up the toe board to behind the dash.
The depression channel obviously is to let the carpet lie flat.