speedo

[firedowg]

I just change gears in my 84 cutlass from 2:41 to 3:42 now the speedo is off. How would i correct it?

 

[85_SS]

I just change gears in my 84 cutlass from 2:41 to 3:42 now the speedo is off. How would i correct it?

You need to change the drive and/or driven speedo gears within the transmission to match the new rear end ratio:

http://www.bgsoflex.com/speedo1.html

 

[ryanwitski]

i just put in 3.42 gears too but have not driven it yet. How bad is it off?

 

[Chevyman85]

Its going to be WAY off! I went from 2.41 to 3.73's and it registered 60MPH at about 40! It'll be a huge difference! Have some buddy pace you and then you can go off of your tach, I did that for awhile till I got the Speedo calibrated. :?

 

[ryanwitski]

thanks! I have a 3.42 so hopefully it won't be that bad, it 5mph fast anyway. If it needs calabrated exactly how do I do that again? Do I have to switch a gear in the speedo or somthing. thanks for the help!

 

[mrapii]

You are going to be about 30% off; at an indicated 58mph you will actually be going about 45mph.

 

[firedowg]

Waaaaaaaaaaaaaaay off. It reads 80 at around 55.

 

[Chevyman85]

thanks! I have a 3.42 so hopefully it won't be that bad, it 5mph fast anyway. If it needs calabrated exactly how do I do that again? Do I have to switch a gear in the speedo or somthing. thanks for the help!

I believe you do. Or get an adjustable one, I had a local shop do it for about $40. I got tired of all the miles that were put on, lol cuz it thought I was going 80MPH, :lol:

 

[ryanwitski]

yea I hate working on the dash area, I'll just get a shop to do it for me most likely.

 

[85_SS]

I just change gears in my 84 cutlass from 2:41 to 3:42 now the speedo is off. How would i correct it?

You need to change the drive and/or driven speedo gears within the transmission to match the new rear end ratio:

http://www.bgsoflex.com/speedo1.html