speed odometer

[Miami Dolphins]

ok guys, driving my 1971 Demon on the interstate after swapping rear ends, went from a 3:91 to a 3:23 it has a 340 4 speed anyway I had the phone with a speed odometer ap showing the actual speed and from 0 to about 20 MPH the speed were pretty even but as a picked up speed the reading became more spread. at 70 on the app I was reading 58 on the car. Question: do this A833 trannies have a gear I can replace or how do I adjust the speed odometer.

Thank you.

 

[cudascott]

Yes you do a little math and purchase the correct color speedo gear and replace
it's a pretty simple job to do.

 

[67Dart273]

Assuming the speedo head in the car is OK, Mopars are the easiest cars on the planet to deal with. This is because the speedo gear mount is on an eccentric, which allows you to install any size speedo gear made into the transmission. There are charts in the shop manuals and also various places around the www listing tire size VS rear gear and speed to figure speedo gear. You need to pull the gear you have. Best way is to beg or borrow a GPS or go find a stretch of highway with mile markers and figure miles at 60 MPH. This gives you an "easy" figure because it's a "mile in a minute" so it's easy to clock

You can also figure it by percentage of change

Free service manual download:

http://www.forabodiesonly.com/mopar/showthread.php?p=1970088617