What is this sound? And how do I fix it? Problem solved!

[Firetodd]

I thought maybe my speedometer cable was going bad because it was intermittently making that spooling up sound. I replaced the cable today. It still makes the sound. Here is a YouTube video I took of the sound: http://youtu.be/GkoWynYDQu4

[Charger4404spd]

Dang son, had my speakers up too loud, skeered the bejeeezus outa me!  I have no idea!

[Firetodd]

Loud right?! Scared me too driving!

[hawkeye]

Could it be the speedometer?  Maybe where the speedo cable goes in is rounded off.  I couldn't see before the noise started but it sure was jumping around a lot when making the noise.  Once the noise stopped it appeared to read correctly.

[XS29L]

Sounds like the speedo to me.  Had a 1986 D 100 and speedo went bad same sound but not as loud , YIKES .

[Cooter]

Speedo head needs to be lubed.

[Firetodd]

I disconnected the speedo cable and the sound went away. I think it must be the actual speedometer head. Oh another thing to work on. Well my 10 year old son took this after our test drive: http://youtu.be/wFw5iiEAO4M

[Troy]

Yeah, sounds like the cable is spinning just fine! That's about like the noise of landing gear cycling on an airliner. Would definitely be confusing in a car...

Troy

[Dino]

http://www.youtube.com/watch?v=0cVlTeIATBs   

[Firetodd]

Cooter, what do you lube the speedo head with?

[Just 6T9 CHGR]

Same thing happened to mine....lube didnt help it.  Gears were stripped out.  Got a used speedo & all was right with the world

[Firetodd]

I mailed the instrument cluster to Mark Gibson (aka theguagedoc) to look it over.

[Firetodd]

Mark Gibson calibrated my gauges and repaired the speedometer head and tachometer. I reinstalled them and my speedometer was still not accurate. I knew it would be off because of the rear end replacement I just did. Anyway, today a replaced the 26 tooth speedometer pinion with a 39 tooth pinion and my speedometer is dead nuts accurate!

[Just 6T9 CHGR]

Good to hear you got it sorted out