I have the gauge cluster from an early 90's model Trans am with a 140 MPH Speedometer. What all is involved in taking the speedometer from that gauge cluster and replacing the 120 MPH Speedometer in the dash of my 92 Firebird (originally a V6 car)? Is it as easy as taking the old one out, and putting the new one in it's place? Any info will be much appreciated.

 

Its probably easier to just replace the entire cluster..Its only a few screws that hold on the gauge bezel then a few more that hold in the cluster. The cluster is just plugged in..Its an easy swap

 

Its a very easy swap, just take the cluster out, pull out a few screws and pop out the speedo. You can use a screwdriver and push lightly on the 4 pins on the back of the cluster that will remove the speedo. But your mileage will not be what the car has any more.

 

Changing the mileage is very easy if you know how...but it's illegal.

 

Is it illegal if the speedo you put in the car has more miles?

 

Do the 140 speedos use a different pulse signal than the 120? I ask because if it does then you will also need the VSS buffer box for the 140 speedometer.
or is it basicly the same gage with a higher top speed?

I am doing this swap to also have the 8000 rpm tach.

In my case I have a dakota digital VSS box so I can adjust the pulse signal for any electronic speedometer but if I need to change it from current setting this means a trip to the chassis dyno to recalibrate the speedometer

 

This whole thing about mileage only becomes illegal if you are attempting to sell the car attempting to make the buying believe it has less mileage than it actually does. Other than that, It is your car. I wouldn't recommend it, unless you keep good records and have documented at what mileage you swapped out the speedometer and what mileage was on the new on..

 

Don't make blanket statements about odometer fraud, titles, etc. they vary much by state. Some states allow you to indicate "true mileage unknown" , some do not, check your state laws, the state inspection manual should be available online.

 

Most of what you say is true; however, clocking an odometer(changing the mileage) is a felony under Federal law if there is intent to defraud.
A person should be very careful when changing the odometer or installing a different speedo.

 

[QUOTE=Yenipenny;5675471]Most of what you say is true; however, clocking an odometer(changing the mileage) is a felony under Federal law if there is intent to defraud.[QUOTE]



there's my blanket just put more correctly

 

RacerM: In this case, Your best bet is to swap the WHOLE CLUSTER.

Any Firebird electric speedo ( 86-92 ) will be pluig and play; V6 or V8. Make note of the odometer readings from the original speedo and the odometer reading from the replacement speedo at the time of the swap. While it IS possible to manipulate the odometer reading inside the electric speedo head,... it is not "easy". The cable type speedos ARE the ones that are easy to re-set !

A V6 tach and a V8 tach are NOT the same. If you use a V6 tach with a V8 engine ( or Visa/Versa ) the tachometer will NOT be accurate unless the signal gets converted. Since your car now appears to have a V8 engine and your still using the V6 Tach,....... your current Tachometer reading is wrong and swapping the whole cluster will correct that problem.