88 124 Speedo gremlins

[BAd124]

Hi all,
I have searched through all the threads but my problem seems to be a unique one. I recently replaced my speedo cable in hopes to fix the typical "wobble". Everything seemed to be great, speedo worked with a steady needle until a few miles into the drive. The needle just dies, consistently.

I cant explain it. When the car sits overnight the first few miles are fine, then bam...speedo and odo both stop. Its almost like a heat related issue but being that its completely mechanical and a very simple straight forward connection, I dont see how that would be it.

The cable is from peachparts so I know its not a cheap part. The only thing different is that its a little longer than the stock one so there is some extra slack. Would that be the cause?

Also, when this does happen, I can hear a buzzing noise coming from the cluster which I would have to assume is the cable spinning in the back. So its not that its somehow coming disconnected from the tranny at least..

Thanks in advance for any insight