ssgsmc19k

I have an 07 Lariat SC 4x4 with the 5.4 23K miles. I put the Evo to monit TSS and OSS now the manul says that if the 2 equal there is no Trans slip. Through all gears except 3rd they do not equal. The trany fluid never gets above 150F. DO I have a problem. Is there supposed to be some slip?? The truck seems to drive right. I usely run the Evo in 1 or 2. I plan on having the Tranny flushed at 25K. Any info would be great. Damn I close on my new house the 24th. Man I so could not handle having to get mager work done on my truck. My warrenty is up in mid May.

shotgun

From PHP's forums:

In first gear the turbine shaft speed will be about 2.88 times the output shaft speed.

In second gear, the TSS will be about 1.55 times OSS.

In third gear, they will be the same.

In fourth, the TSS will be LESS than the OSS because of the .71:1 overdrive.

When the torque converter clutch is applied, the engine RPM should always just about match the TSS.

The sensor inputs to the PCM have to do with the gear ratios in the transmission and the computer's way of self-diagnosis to determine whether or not there is slippage and whether or not the commanded shift actually took place.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~

Engine --> [Converter] --> Input Shaft --> [Tranmission] --> Output Shaft

or more specifically...

Engine --> Input Shaft --> Output Shaft


Engine --> Input Shaft:

• Same if Converter is locked
• Different if Converter is unlocked (difference varies depending on load)

Input Shaft --> Output Shaft (Based on 4R75 Transmission)

• 1st gear - Input is 2.8387 x Output (2.8387:1)
• 2nd gear - Input is 1.5545 x Output (1.5545:1)
• 3rd gear - Input is the same as Output (1.0000:1)
• 4th gear - Input is 0.6984 x Output (0.9084:1)

Slip in the transmission can be easily calculated by finding the input:output ratio and see if it matches the current ratio for the selected gear. If it doesn't match, then slip is present.

Slip in the converter is only determined during lockup.