67 R/T Speedometer/Speedometer Cable ???

[69L48Z27]

I'm down to the last few items to work out on the R/T, one being a bouncing speedometer needle.

When I put the car together I had no speedometer, I also had no reference if it worked prior to restoration either. I got home, crawled under the car, disconnected cable at the trans and ran a drill on the cable. Speedometer works, no bouncing or anything. I hooked it back up to the trans and went for a drive, now it works but interimently the needle bounces. I have not confirmed the 'clocking' of trans gear yet either.

In your experience, what am I trying to fix? Cable, trans gear, speedometer itself?

Thank you!

 

[FrnkNsteen]

Could be bad teeth on the gear in transmission. If it was smooth with a drill, but jumping around when connected to the transmission, that would lead me to look at the speedometer gear in the transmission for bad teeth.

That or maybe the bend to go into the transmission is adding friction to the cable (assuming it was held more straight when you ran the drill).

 

[PurpleBeeper]

"Usually" that's the speedometer cable hanging up inside the cable housing. You could try some type of lubricant (e.g. graphite), try to eliminate any tight bends in the speedometer cable, or replace it.

 

[YY1]

I wonder if the tooth engagement depth is off where the cable goes into the trans.

 

[Don Frelier]

One more thing you can do is check the cable for breaks in the strands. Pull it out of the casing, make a loop kind of a u shape downwards between your two hands. Spin one end with your fingers and let the other freewheel. If it jumps on the loose end you have broken strands.

 

[69L48Z27]

Thanks everyone. Glad to hear no one had this experience and the speedo was the problem.

I was thinking about the gear in the trans too, hoping the fresh rebuild would have caught any issues but I need to check the engagement settings too, how it's clocked in the trans.

I'll take the cable out and clean it up real good and lube.

Thx again!

 

[AR67GTX]

"Usually" that's the speedometer cable hanging up inside the cable housing. You could try some type of lubricant (e.g. graphite), try to eliminate any tight bends in the speedometer cable, or replace it.

I agree. I went through this last year after I had my speedometer rebuilt. It clicked and jumped on reinstallation and I sent it back to the restorer. He checked it and said it tested out fine. Bought two different cables and finally found one that ran smooth. I lubed the cable with Tri Flow dry lubricant which is really slick stuff and so far it's running pretty smooth.

https://triflowlubricants.com/product/superior-dry-lubricant

 

[Officer Higgins]

Bounces like yours, never have figured it out , not so sure they didn't bounce when new?

 

[69L48Z27]

I agree. I went through this last year after I had my speedometer rebuilt. It clicked and jumped on reinstallation and I sent it back to the restorer. He checked it and said it tested out fine. Bought two different cables and finally found one that ran smooth. I lubed the cable with Tri Flow dry lubricant which is really slick stuff and so far it's running pretty smooth.

https://triflowlubricants.com/product/superior-dry-lubricant

Thanks! Sometimes it's really all over the place then all the sudden it's smooth for a bit. I'll pull the cable next and see if it can get the original lubed up.

 

[69L48Z27]

Bounces like yours, never have figured it out , not so sure they didn't bounce when new?

I'm going to guess they didn't. It's super annoying watching this thing bounce around.

 

[Officer Higgins]

Mine only bouncing at low mph steady at around thirty on up.

 

[69L48Z27]

Well, after 6" of snow already today here in PA I think I won't know if this is fixed until spring at this point. Snow already... Ugh.

 

[Don Frelier]

I measured 14" this morning. Good thing I put the Charger away on Monday.

 

[AR67GTX]

I'm discounting that it's your speedometer head because you said it ran smooth on a drill from the transmission end. Thinking about it some more that could mean your speedometer cable is OK too. So that could point to a bad gear in the transmission. These things are touchy. My speedometer would take wild swings ever few seconds and then settle down for a couple of seconds and then swing wildly again. The gage rebuilder said it was definitely bad but then I found out I had a cable problem too.

 

[69L48Z27]

I'm discounting that it's your speedometer head because you said it ran smooth on a drill from the transmission end. Thinking about it some more that could mean your speedometer cable is OK too. So that could point to a bad gear in the transmission. These things are touchy. My speedometer would take wild swings ever few seconds and then settle down for a couple of seconds and then swing wildly again. The gage rebuilder said it was definitely bad but then I found out I had a cable problem too.

What you described is kinda what I meant chasing too. Good for a second then not.