Shift Point with 4.10 Gears

[johnsonsinutah]

I'm using predator U7146 on a 98 Mustang GT AODE, current Predator revision. I just installed 4.10 gears and changed out the speedo gear, but that still leaves me about 15% off in terms of speedometer accuracy. Not sure if the car shifts based on RPM or speed but, should I adjust my shift points? If so, anyone have any idea how much or how to calculate the adjustment? The old gears were stock 3.27's.

[Dazzzy]

you couldve just changed it in the predator.

[Vas@Diablosport]

I'm using predator U7146 on a 98 Mustang GT AODE, current Predator revision. I just installed 4.10 gears and changed out the speedo gear, but that still leaves me about 15% off in terms of speedometer accuracy. Not sure if the car shifts based on RPM or speed but, should I adjust my shift points? If so, anyone have any idea how much or how to calculate the adjustment? The old gears were stock 3.27's.

The speedometer should not be 15% off if the correct speedo gear is installed. At what rpm is the vehicle shifting at now? And where was it shifting before the gear swap?

[Vas@Diablosport]

you couldve just changed it in the predator.

What could he have changed? The speedometer on 98 mustangs is not controlled through the PCM therefore cannot be changed through the predator. It has a mechanical speedo and can only be adjusted by replacing the speedo gear.

[johnsonsinutah]

Unfortunately I haven't been able to find a speedo gear that adjustes for 4.10 gears in an automatic, the gear I used is good through 3.55 gears, but there isn't anything beyond that, at least not that I can find. I don't know about the pre gear change shift points, it's shifting now around 3500 RPM so it seems ok to me, I've just seen a lot of blog chatter that the shift points get messed up with a gear change. I very seldom "floor it" I think the issues documented relate to WOT shift points.