A tranny problem (no its not my car)

[THE VIBERATOR]

I am doing a personal favor for a friend of mine in this post. He owns a 2003 Ford Taurus (thus, the tranny problem). He wants to know if there is a way to stop his tranny from slipping or doing whatever it is doing, which i will explain right now, before he takes it to a shop for replacement.He can cruise fine. He has no problems on light acceleration, even moderate and slightly heavy acceleration. Tranny shifts fine. However, when it is at full throttle, his 2nd gear slips at about 4 grand, and he has to let off to let it shift and go back to cruising. He only has this problem at full throttle in 2nd gear at 4k rpm. He hasnt tried to go past 2nd, but that'd just aid the eventual destruction of the car if he did anyways. It's a tranny slip. So...can anyone give my buddy a few suggestions on some things he could do to try and get rid of it? Or does a slip mean a new tranny is in order?Since it's a Ford, I'm thinking it's time for a new tranny...

[blue_can]

Sounds like there is a malfunction with the boost pressure since it only happens at full throttle. If he is lucky it may just be some debris cloggning the pressure regulation valve. I don't know enough about the Taurus transmission to know whether pressure regulation is manual (cable operating a throttle valve) of electronic.Two things to try is to do simply change the fluid and/or check the line pressure at idle and at stall. The pressure check will tell if there is a problem with the boost pressure.If that checks out okay then he may be unlucky and have worn clutch plates and/or bands depending on the design of the transmission.

[THE VIBERATOR]

It's an automatic, and I believe he has a throttle cable. Chances are there's something wrong with the boost pressure, but neither me nor any of my friends have learned enough at school to check that. I'm going to hop on ConsumerGuide and check to see if this happens to alot of Taurus transmissions. I'm going to assume that he'll just want to take it in for a new transmission, because I'm thinking the same thing you are. However, i will tell him what to do before he does. Thanks!Anyone else have any thoughts?

[ColonelPanic]

How many miles on this thing? I keep hearing this vintage Taurus has a transmission life expectancy of 80,000-100,000 miles.

[THE VIBERATOR]

70,600 miles. A bit premature for the tranny to go.

[blue_can]

I assumed it was an automatic so my post was based on that assumption. If the throttle valve in the transmission is indeed operated by a cable from the gas pedal (rather than by a solenoid) it may just be that the cable needs adjustment. They normally have a locknut that you can loosen and then adjust the tension. If it has become slack it may not be moving to the end and that would cause a drop in the boost pressure.Measuring line pressure is quite easy. Most transmissions have a tapped port for this. You undo the bolt and screw in an oil pressure gauge. You can then start up the car and place the gear selector in "D" as well as "R" and measure the forward and reverse line pressure.Most transmission gauges have a low and a high guage so you can use the most appropriate one. Some of them also allow you to drive around while it is hooked up. I have a set but I was using it to test the transmission on one of my cars which was malfunctioning and the reverse pressure was so high at stall that the needle no longer goes back to zero fully. (it was well over 400 PSI at stall) The idea is to start with the higher guage and then use the lower one if appropriate.To measure the pressure at stall, you just hold down the brake and repeat the measurements at full throttle. You need to be careful not to let the brake go while doing this. Also only for a few seconds since all the energy is being dissipated in the torque converter.You then check the readings you get with what it should be. This info should be in the transmission service/rebuild manual.It would be pity if this was a simple fix and he ends up putting a new transmission in.

[THE VIBERATOR]

Yep, boy am I glad I just learned about oil pressure gauges at school I need to find one first, but all of that transmission-ey stuff is kindof above my head at the moment. I have to get into Transmissions class first before i really can feel safe with what I'm doing lol. Thanks for the tips though, I will recommend them to him.