Put in a rebuilt transmission. It is gettng codes of P0720,P0730, and P2701. Truck will not shift past 3rd gear.

Does the ouput speed sensor reading supposed to match the input speed exactly ALL the time or only whne up to speed and driving. My OS reading lags behind unitl up to speed and then is faster for a split second when you let off the gas. Trying to figure out if the P0720 code is actually a bad sensor or if it being set from the other 2 codes. After researching, it could be either way. Shifts fine from 1st to 3rd, nothing higher though.

 

The output shaft sensor should equal the input sensor only when the trans is in 5th (1:1 ratio) gear. Any other time it will not be equal.

In 1, 2, 3, and 4 the input speed sensor will read faster. In 5th gear they are equal. In 6th gear (0.71:1 ratio) the output will be turning faster than the input.

 

Thanks Mark. Hoping you would see this soon. heard you were he one with the knowledge.

OK, now I am really stumped. When I am not accelerating, they read within 10 rpm's of each other. I know its not in 5th though. Only shifting 2 times from a dead stop and reading WAY to high rpm's for the speed to be in 5th.

Forgot to add, trans temp reached 195* in less than a 4 mile test drive. It never ran this hot unloaded.