Automatic "clutch" slipping

[MooseNelson]

Hi, have a T99 and after the car is warm (usually on long drives and such) feels as though the "clutch" is slipping. Heard that automatic transmissions don't have them, but it feels the same as when the clutch was blown on my 5-speed.

-Moose

[shorod]

Automatic transmissions have multiple clutches, but they are somewhat different from what a manual transmission uses.

Can you describe the "slipping?" Does the "slip" occur only during shifts, or when accelerating under load? If during shifts, you may be experiencing the programmed "slip." The computer controlled transmission, when up to operating temperature, will retard the ignition timing at the moment the transmission shifts to allow for a smoother shift, one that ideally the driver won't feel. The retarding of timing is to lower the torque during the shift so as not to wear the clutches out as quickly since the more slip that's programmed in, the smoother the shift. The smoothness of the shift is based on line pressure.

That's essentially the way the transmission in the 3rd Gen Taurus SHO works, and I believe the non-SHO Taurus transmission control is similar. I wish I could remember where I read this....

-Rod

[MooseNelson]

Hey thanks for this info.

It "slips" on accelleration, feels just like whatever wheel or belt should be catching, is just spinning a bit, obviously when it's hot it slips easier...

[shorod]

Hmm, that doesn't sound good. Have you checked the fluid level in the transmission? If so, is the level correct, and is it pink with very little odor or brown with a strong odor? If the fluid level is low, but it is still pink with very little odor, you can try adding some fluid to get the level where it should be and see if that helps. If the fluid is brown and has a strong odor, replace the fluid and filter.

By just removing the drain pan you will only drain about half of the fluid in the transmission. There will still be fluid in the torque converter and lines if you have a transmission cooler. You will either want to drain and refill a few times or have the system flushed. Some people have strong feelings against flushing transmissions, so do some research and make that decision for yourself.

If the fluid seems fine all around, then you may need to find a shop with a scan tool that can monitor the transmission sensors in the datastream mode. They will want to pay attention to the input speed and output speed sensors, as well as pressures and the operation of various solenoids. With the scan tool connected and a technician that understands what he or she is seeing on the tool, they should be able to determine if the transmission is actually shifting or if something else is wrong.

-Rod