Bouncy speedometer needle

[mountain14er]

Just got back from a long trip and among the half-dozen or so rattles and chatters is the speedo needle. At high speed especially it bounces a lot, going from the real speed on up (say 60 but bouncing to 80). So the two concerns are the innacurace and the noise. The two most possible sources seem to be the gear at the t-case or the connection to the cluster.

Anyone have any insight about which source is the likely culprit and how involved the fix is?

 

[t.lay]

In my experience there's usually more problems at the instrument cluster - of course it's easier to check the gears at the t-case, so you might start there. Could be you're speedo cable is binding a bit.

 

[Mr Joe]

I corrected mine by disconnecting the cable at the speedo and shooting a little lubricant down the cable.

 

[cakedude]

Take the speedometer cable off the truck. Get some graphite powder (used for locks) from the hardware store. Attach a drill to one end of the cable and work the graphite down into the cable. The grapite works much better than oil. Good Luck.

Grant

 

[mountain14er]

Thanks for the input. I was guessing this was one of those jobs where you just have to tear it apart and see what's up. These are good suggestions though. I know for bikes, I avoid oiling cables so I'll try that graphite.

 

[thegreatjustino]

Yup, lube er up. I've never had to do so in my Bronco, but my '65 Mustang's speedometer is notorious for bouncing around every few years. A little lube and it works fine again.

 

[brian72]

You suppose lube on a brand new cable is needed? I have the bouncing needle. Sometimes, though, it is very steady.

 

[az_shootist]

I would say lube is required. I just put in a new cable (right before reading this thread) that was noticeably dry. ...now I have a bouncing needle. Oh yeah, my last cable started bouncing about 200 miles before it snapped the inner cable, so I'm going get this lubed up soon.

 

[kntr]

New cable is only $45

 

[brian72]

What I meant to say was, I have a new cable installed and it is still bouncing the speedo needle. I guess lube is still required for a new cable?

 

[302fix]

To correct the speed you might need a new gear:
http://www.broncohio.com/tech/calculations.html

I've done this to my Cougar when I switched to 3.40 gears but didn't do any correction to the Bronco when I added taller tires. I just use my GPS