Bouncy speedometer

[crpntr78]

Good morning GMSB folks. I'm having an issue with my speedometer, 86k10, 700R4-208. I have replaced the speedo, the driven gear in T-case, pulled cable from sheath, lubed up cable and inside sheath and checked to make sure when routing cable there were no hard bends or kinks. Speedo still bounces. Sometimes when backing up I can hear a clicking sound coming from the speedo. Any other suggestions? Thanks.

 

[RetroC10Sport]

Keeping an eye on this topic, my daughter's truck does the same thing.

 

[theblindchicken]

Have you tried getting new shocks???


How much is it bouncing? Slight oscillation at a given rpm? Bounces way up and down (10+mph difference) on braking and acceleration? Bounces, but wont go any higher than a certain speed?


Used to have the issue of it bouncing way up and back down (like an empty fuel tank sloshing around). Pretty sure replaced the speedo cable and it fixed it.

Also had one that wouldnt go higher than about 35mph, that turned out to be worn out magnets in the speedo.

 

[bedwards]

Mine is a 85 bone stock with the 305 700r4 and was noisy and bouncy like yours. I backed the cable off where it connects to the speedometer as much as I could and all the noise and bounce disappeared. It's almost as though it was pressing too tight on the back of the speedo.

 

[theblindchicken]

Too tight of a connection causing it to bind up, eh?

 

[crpntr78]

Thanks for the feedback. 1st, shocks are semi new(2 years old). It's bouncy from the get go. I haven't had it out of town since doing this work so have only seen it up to about 40. It held steady only once. It bounces about 10 mph either direction around my estimated speed. I thought I would get a new cable but wanted to hear what you all had to say first. Again thanks as you guys have given me some food for thought.

 

[Camar068]

post results plz, mine bounces about 5mph.

 

[theblindchicken]

Thanks for the feedback. 1st, shocks are semi new(2 years old). It's bouncy from the get go. I haven't had it out of town since doing this work so have only seen it up to about 40. It held steady only once. It bounces about 10 mph either direction around my estimated speed. I thought I would get a new cable but wanted to hear what you all had to say first. Again thanks as you guys have given me some food for thought.

Was just joking a little bit about the shocks haha.

Not 100%, but if I remember correctly, the bouncing needle is mainly cause by binding in the speedo cable since the input into the gauge is irregular. May just need a quick bit of lubrication.

Make sure to use dry lubricants, since grease and oils will attract dirt and make it worse in the long run.

 

[1973c10]

I had one do the same thing I replaced the speedo cable
problem solved

 

[crpntr78]

Good morning GMSB folks. I'm having an issue with my speedometer, 86k10, 700R4-208. I have replaced the speedo, the driven gear in T-case, pulled cable from sheath, lubed up cable and inside sheath and checked to make sure when routing cable there were no hard bends or kinks. Speedo still bounces. Sometimes when backing up I can hear a clicking sound coming from the speedo. Any other suggestions? Thanks.

Thanks for the input guys. Finally had a chance to change speedo cable with AC Delco one and speedometer works like a charm now. Steady and solid, no bouncy anymore!

 

[spanky55amg]

My truck is **** the same... It will level out if I am cruising. Im not going to bother lubing. The truck is 33+ years old. Im just going to replace the cable.
Do you have to lube the new cable?

 

[crpntr78]

No I didn't lube it, although that probably wouldn't hurt.