I had the rear switched out in my 90 camaro [305 tbi, auto] The stock 2.73 rear died, so I found a 3.42 rear from an 84 camaro in a local yard.

Everything installed ok.

But I have the following problems:

1) Speedometer is way off: at 50 mph, my speedo says I'm going 60 mph [according to the construction zone MPH signs.... 8) ]

2) My cruise control quit working.

Any ideas on what I need to do to fix this mess?

 

cruise should still work,


get the correct speedo gears. what was the other car? auto or stick?


if it had a 700r4 as well then see if you can get the speedo gears. otherwise do a search. there is alot! of info on the speedo gears

 

Do I need to change my Vehicle Speed Sensor?

I don't know what kind of transmission the 84 camaro had. I was only able to get the 3.42 rear out of it.

I've read that the VSS helps run the cruise control....

 

no you only need your stock sender. it is just a matter of switching the speedo gears on the sender, possiably on the trans. (but, you are in luck. the 700r4 is very easy to switch both gears)



the cruise only needs a speed signal from your sensor. if it thinks you are doing 60 (even though you are going 50) it still works. it just keeps the speed you are traveling


perhaps you were under the hood? moved a vac. line? did you work under the dash for any reason?

 

https://www.thirdgen.org/techbb2/sho...eedo+calibrate




here this takes all the fun of looking for you,


https://www.thirdgen.org/techbb2/sho...edo+calculator

just read this post from the start. they give you info for the 700r4 as well. like 700r4.com for a calculator