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OldChevy1954 · 03-30-2023, 01:55 PM

It's an LMC speedometer only 3 or 4 years old.
I have replaced the cable a couple times since I owned the truck
It does not have a speed reduction unit on it at this time. I was able to get the proper GM plastic gear for inside the transfer case to get me real accurate 3 years ago.

The speedo cable goes to the side of the NP205 transfer case.

It was working real good until recently. I had someone drive 60 mph next to me and my speedo was saying 75. It's more accurate at lower mph, then as I get up around 65 the difference is exaggerated. More speed = more crazy reading.

It does not jump around at all.

I'm thinking something inside the head unit itself?

03-30-2023, 01:55 PM	#6
OldChevy1954 Registered User Join Date: May 2016 Location: Salisbury, MD Posts: 56	Re: Speedometer Acting Strange It's an LMC speedometer only 3 or 4 years old. I have replaced the cable a couple times since I owned the truck It does not have a speed reduction unit on it at this time. I was able to get the proper GM plastic gear for inside the transfer case to get me real accurate 3 years ago. The speedo cable goes to the side of the NP205 transfer case. It was working real good until recently. I had someone drive 60 mph next to me and my speedo was saying 75. It's more accurate at lower mph, then as I get up around 65 the difference is exaggerated. More speed = more crazy reading. It does not jump around at all. I'm thinking something inside the head unit itself?