After getting my 87 T/A out on the road I found out that my odometer isnt working at all. My speedometer is working but not accurately. From what I have found the gear or small motor inside the cluster is likely bad causing the odo not to roll.

I have an extra cluster that I pulled from a parts car but when I took the outer covers off the tachometer says 6 cylinder (8000 RPM). I was looking to swap the whole cluster in to see if it would fix my odometer so I know what the issue is.

The speedometer in this cluster is 120 MPH and mine in the car is 140 MPH, can I swap out just the speedo & odometer into my cluster or will the needle be off on the 120?

I am not sure where the "conversion" happens in these clusters

 

I believe I found the answer to my question, if I swap the circuit board above the speedo with it then it should work correctly. Is this correct?

 

Interesting topic. I've wondered what it would take to go from the 120MPH speedo to the 140MPH unit. I hope it's as easy as taking that little PC board along with the speedo.

 

Well I was hoping I could go ahead and answer your question DynoDave43 but I ended up figuring out that I could just swap the odometer so I did that and voila

 

I'm glad you got it going.

 

One thing I did notice while I had it all apart is the pc board for the 120 MPH speedo was a lot smaller than the one for the 140 MPH, I dont know if it would make an actual difference for swapping the speedo but they are definitely different in size and layout.