in dash "rattling or slipping" sound in the morning Speedo cable?

ok so my 96 3.4 has been making a loud sound in the morning that comes from about right behind the left side of the cluster. it only happens when the truck is below about 40 degree's and is the loudest on mornings below freezing. once the truck warms up all the way, "I have been driving for about 15-20 minutes" it goes away it is accompanied by my speedo needle wiggling around in a 5MPH up or down, it jumps around whole time. then the noise stopes and it calms down back to normal. if I don't leave until the afternoon it never does it. any and all Ideas welcome!! I would love to get it fixed

my current idea is that the speedo cable needs some oil! how would I go about adding it? and where is the cable on this truck?

 

bump!!!!! how do you oil the speedo cable??

 

That sure does sound like a speedo cable. I thought the 96 would have an electronic cluster in it, but I am no expert.

Never bothered to lube the noisy cable in my 86 when I had it. It made that noise for years and never went out. Not sure what you would use for lubing it, I would think squirting some engine oil into the cable housing from behind the dash would work. That way the gravity would take over and the oil should migrate down towards the transmission.

 

you have to pull the dash, pita! and hooking it up takes two ppl. use white lithium grease