Torque Converter Lockup Q
 

My Stang has a screwy speedometer..it jumps all over the place.. Now I'm wondering exactly how the TCC operation in these cars is.. My Camaro has a screwy speedo and when it passes over 40 mph it causes the torque converter to lock and unlock real quick over and over...will a stock Mustang lockup converter do the same thing? Most of the time the speedo is reading around 80 mph during cruise and it bounces around 5-10 mph around that range. I'm asking because I figured the converter would try to lock, but it doesn't..I've never heard the torque converter lock in the Mustang..so I'm thinking either a replacement non-lockup converter, or the prev. owner cut the wires to the TCC. Thanks guys.

In the AOD it is a mecanical lockup based on gear selection not speed the AOD-E is speed based but in 91 you have the AOD sounds to me like your speedo cable is probaly broken.

Yes, the inner shaft on the input shaft of the AOD controls lock up in your converter. The stock converter on the AOD is very tight so you will never actualy feel it lock up. I too agree that you just need to replace you speed-o cable.

Is the lockup immediate then, like as soon as it hits 3rd gear it locks, so you can't tell? I was just wondering, because I've never heard/felt any sort of a lockup..and I have a sensitive ***.

By the way..speedo cable and gear was checked by a trans shop and they said they were both new or working properly.. But then again, this is the same shop that re-installed my BENT, LEAKING differential cover after they serviced the d*mn thing....