Ticking on deceleration in time with speedometer wobble

[ComatoseLlama]

Hello,

I've noticed a new ticking noise in my truck while driving it around today. The tick is a remarkably similar sound to a blown exhaust manifold on a gas truck, but engine RPM has no effect. I couldn't get a video with the sound, the cab is too noisy with my tore up shifter boots.

As I come to a stop a consistent ticking noise starts to happen around 27mph and stops at around 5mph. The speed of the tick is speed dependent (like how bad brakes sound), and you can watch the speedo jump back and forth (+/- 2.5mph) in perfect sync with the ticking noise. If I push the accelerator down just far enough so that I am no longer losing speed but am also not gaining speed the noise goes away. My speedometer does not jump back and forth above this speed.

I do not think it is the engine, since I can take the truck out of gear at 70mph, and let it idle down to a stop and the noise WILL NOT occur until the speed reaches ~27mph. My transmission is getting pretty loose, lots of gear rattle and such, but I don't think it's a transmission issue as the noise happens in and out of gear, clutch in clutch out. The noise occurs much less often when decelerating in gear, but still happens sometimes. Pushing in the clutch does not help. I took a video of the clutch assembly spinning and every thing seems smooth to me. I can feel it in my feet somewhat so it's close to the transmission tunnel.

Any ideas? It seems like it might be the speedo cable but I can't say I've ever heard of a broken speedometer cable.

Thanks,
CL

 

[IDIBRONCO]

I think a broken speedometer cable usually means a speedometer that doesn't work.

 

[Scotty4]

My speedo cable ticked for a while and was pretty jumpy and erratic. Til one day it clicked loud once, and that was it. Dakota digital dash is in my future.

 

[IDIBRONCO]

I can add that when the speedometer drive gear in my transfer case was going out, the needle would jump a little bit. Then as the wear on the gear increased, so did the movement of the needle. I was running straight exhaust so if it was clicking, I couldn't hear it.

 

[Philip1]

The liner in the speedometer cable that allows it to move freely might be worn out causing it to catch and release causing a clicking sound and making the speedometer needle wobble.

 

[IDIBRONCO]

The liner in the speedometer cable that allows it to move freely might be worn out causing it to catch and release causing a clicking sound and making the speedometer needle wobble.

That's a good suggestion. Unhook the speedo cable underneath the truck and drive it around for a little bit. You won't be able to keep an eye on your speed, but you can listen for the noise.

 

[ComatoseLlama]

I finally got a good video of the sound

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I’m going to disconnect the speedo tomorrow and hopefully that will fix it

 

[ComatoseLlama]

Well I was driving down the highway and all of a sudden my speedo said 0mph and the noise went away so I guess it was the cable! Not too bad of an issue besides no cruise control

 

[IDIBRONCO]

Well now you know.