torque converter shifting in and out

[rkd68]

thought i would throw my 2 cents worth of questioning in. my issue is that i can feel something slipping in and out at highway speeds. i dont lose mph, but i can see the tach gain and drop about 300 rpms. even if i shift out of O/D to D it still feels like its shifting. i have the auto 4.0.

oh ford guru gods of almighty wisdom, help me......lol

 

[rkd68]

gonna add more on my post for my torque converter issue. have been doing ALOT of online research and reading and from my best guess, im having troubles with the lock-up clutch. this is supposed to lock the converter together at highway speeds to help increase fuel economy by eliminating the slip, which is marginal, something like 2-8%. but as i meantioned, at highway speeds, it feels like its still shifting in and out and i can see the rpms change but not the mph. im still investigating this lock-up clutch but bare with me, so far its a solo act in research and im far from being a transmission guy. im learning as i go.

 

[Tedybear]

http://tech.oldsgmail.com/trans_TCC.php

The TCC should engage at about 45ish MPH or so. (all depends on the specs, etc...) A lot of car owners back in the early days of this system reported a "Chuggle". Where by you'd be doing about 45mph---The TCC would kick 'on'...And, if the driver didn't accel slightly? The speed would drop below the threshold and the TCC would kick 'off'. A driver could hold the speed at about 45? And it would "surge" or "Chuggle".

The solution back in the day? Instruct driver to go a bit faster, or slower! LOL!! (GM had this problem BIG TIME according to one of my tech instructors.)

If you are going 55-65mph and it's doing this while going a steady speed? I'd say the TCC is slipping. Question would be...Why? It's controlled by a servo in the valve body of the transmission. The servo could be leaky, defective...or just a crappy electrical connection---Or the plates in the Torque Converter could be "toasted"..and slipping internally.

More diagnostic work is needed...Might be worthwhile to get the wiring diagram...using a good ol' fashion test light on that wire that feed the TCC...Take it out for a drive. If the light goes 'on'? The TCC is engaged---Now if it starts to surge, but the light remains 'on' while it's doing so? Problem could be internal or the TC itself.

S-

 

[rkd68]

i like the idea of putting test light inline, if only i had thought of that id be the genius......lol. so now my search is for the electrics on this thing and start testing.

thanks 'S-'

 

[Bruce]

I have seen a TPS, or speed sensor, or mass airflow sensor or speed sensor cause this to happen because of these sensors not reading properly and sending bad readings to computer. Best thing to do is if you have an access to a good scanner put scanner on it and go for a ride and see if anything out of the ordinary is happening.

 

[rkd68]

with 88k miles on it and never having and real tune up done to it other than oil changes and cleaning the k&n filter, ive often wondered about the mass airflow sensor being dirty. lucky for me its easy to get at once the filter is removed. probably a quick spray of cleaner on it and viola, life is good.

ive also had issues with the 4x4 not engaging this past winter and have heard the vacuum lines/system can be the cause and a major pain for many components. once weather actually gets nice i want to take a full look at all the vacuum system and remedy that.

 

[Tedybear]

The test light idea is brought to you by the auto tech instructor I had in college. (he worked many years for Chevy as a tech and shop manager. he's seen the chuggle issue a lot on the newer cars of the day with a TCC)

Scan tool on a EEC-4 system? To be honest it's pretty much...how to say.. Good for pulling codes and basic tests...but for info on the fly? Next to useless.

Ford actually came out with a "Break Out" box for the EEC system to test parts while driving.

If you can't get an answer on which wire goes from the computer to the TCC solenoid? I'll dig up my shop manual for our BII. Pretty sure it will be the same 'pin' on the computer. One end of the test light to ground, and tie in the test lights 'smart end' (or you can also use a multimeter) into the feed coming off that pin.

As for the 4x4? Ours is just RWD...so I can't help much, other then to mention that IF it has vacuum lines working the 4x4? That's a disaster waiting to happen when the vacuum lines start to harden and crack. (pretty sure it's not......but not 100%)

S-

 

[TwoWhels]

Well I hated it. My transmission does it all the time (both of them LOL)
What I did is leave the computer hooked up to the TCC solenoid and added another wire to the ground side of the switch (the computer grounds the TCC solenoid to lock the converter) and put a toggle switch between it and ground ... That way I could manually lock the converter.


The way the A4ld works ... TCC will not lock in 1st or 2nd.
And you need enough pressure to lock the TCC (3rd and 4th)

I was flipping the switch every time I got up to 45 and again below 45.

Did some testing and it works fine grounded all the time.

If I need to accelerate it will disengage (TCC) then down shift if needed.
When I slow to a stop when it shifts to 2nd it disengages.

Every once in awhile I can feel it locked up in 3rd when slowing down but it is only for a moment.

So I just leave the switch to the grounded position all the time now.

To me it shifts perfect (for an automatic) especially a A4LD!!!