Car will not go over 54 mph

[Itsmurphintime]

So I recently replaced the t45 in my 97 gt with a tr3650. The car shifts great but as soon as I hit 54 mph specifically the car cuts in and out like it’s being choked.

 

[wmburns]

Ford uses two types of transmission speed sensors. VSS and OSS.

The 1996-1998 uses a contact worm gear VSS sensor
The 1999-2004 uses a non contact reluctor wheel OSS sensor.

The output of the VSS sensor is NOT compatible to the OSS sensor. The wiring is different between the two sensor types. Plus the sensor type needs to match what the PCM is expecting.

Just wondering.........Does the speedometer work? What speed is the speedometer displaying at 54 MPH?

I really suspect that the car is cutting out because the PCM "thinks" that the car is going tooooooooo fast.

Research an extended range SpeedCal to convert OSS signal to VSS style.

Here's some more information that may help you to understand the difference between a VSS and OSS sensor.

T-45 Tail Shaft Swap
https://www.allfordmustangs.com/forums/4-6l-tech/140694-t-45-tail-shaft-swap.html

 

[Itsmurphintime]

Ford uses two types of transmission speed sensors. VSS and OSS.

The 1996-1998 uses a contact worm gear VSS sensor
The 1999-2004 uses a non contact reluctor wheel OSS sensor.

The output of the VSS sensor is NOT compatible to the OSS sensor. The wiring is different between the two sensor types. Plus the sensor type needs to match what the PCM is expecting.

Just wondering.........Does the speedometer work? What speed is the speedometer displaying at 54 MPH?

I really suspect that the car is cutting out because the PCM "thinks" that the car is going tooooooooo fast.

Research an extended range SpeedCal to convert OSS signal to VSS style.

Here's some more information that may help you to understand the difference between a VSS and OSS sensor.

T-45 Tail Shaft Swap
https://www.allfordmustangs.com/forums/4-6l-tech/140694-t-45-tail-shaft-swap.html

I ended up resolving the problem with a speedcal from Dallas mustang. Thanks for the suggestions!

 

[98Mustang2017]

I ended up resolving the problem with a speedcal from Dallas mustang. Thanks for the suggestions!

54mph fixxed with a speedcal?
i really want to ask: What gear ratio/tire size you runnin' ?

I'm on stock tire and have 4.56 and topped out at 68mph. I'd like to see how 5.71's act just out of curiosity.