1996 C3500 dually....speedometer no longer accurate after transmission swap..
 

I've trolled around the internet looking for answers and all I have found is take it to the stealership.?!?!

One of our work trucks we dropped at the transmission shop a while ago and had the 4L80 replaced. After quite a while the driver finally let me know the speedometer was no longer accurate. At 60 its showing close to 80-.

Its an electronic transmission and no speedo gear so I assume re-setting it is done through a scanner or computer.


What is the correct terminology for what needs to be done, what has happened, or basically whats going on??

Thanks

Re: 1996 C3500 dually....speedometer no longer accurate after transmission swap..
 

could be the speed sensor , and its just a coincidence its went out soon as u got transmission done.

i tested my steam gauge via my phone app it was very accurate.

other thing might be the gauge cluster speedometer itself went bad or starting to.

needle pointer type?