97 5R55E TCC Slipping?

[trevvor]

Is this a problem, or is it not?

At 59k miles I had my 97, 5R55E tranny fluid changed as per 60k recommendations. Had an independent shop drop the pan and replace the filter, I don't think they flushed it cause they only charged my $11.25 for the ATF.

At about 60K the tranny begins to slip in 1st when cold. My mechanic recommends a transmission shop. The transmission shop, after tear down, recommends a rebuild (of course). I get it back and now there is a new problem.

When in OD, TCC seems to slip when a slight load is experienced. I'm going down the road, 50 mph +, always speeding up and slowing down with traffic, but when I speed up, it feels like tranny slips. Tach will rise by 100 or so and then drop back. When I'm on the freeway, cruise control on, go up a slight hill, same thing happens; rpm comes up and then drops down. It does this constantly whenever there is any changing load on the tranny while in OD. After it gets warmed up fairly well it also shudders, more so though at higher speeds like 65-70. The move from San Diego to Phoenix was very annoying.

I've brought it back to the shop three times. The first time they replaced the torque converter. The second time they said they didn't find anything wrong. The third time I test drove with the service manager; he confirmed the issue. Then the shop owner drove it and the senior tech drove it. Finally the senior tech test drove it with me, confirmed the issue and explained that it was a normal process (TCC lockup). He said it never worked properly from the day I bought it (I bought it brand new).

I've brought it to 5 different independent shops and a dealership since then. All confirmed that it was a problem and each gave me different explainations (and they all want to rebuild it).

It seems like the torque converter clutch isn't fully locking up, or staying locked. I really can't believe that this is normal. I've looked through tons of post but haven't found anything like this.

Has anyone experienced this or have a clue as to whats happening? Does anyone know of a reputable shop in Phoenix?

Thanks

P.S. This site is a lifesaver. I've learned so much in the past hour; I wish I'd found it sooner.

 

[Opera House]

Your initial problem is probably because of valve body gasket blowing out. The 5R55E is notorious for having loose valve body bolts that cause this. Ford dealer will replace this with a rebuilt valve body for about $800. Seems they don't like to think about the actual problem and replace everything. Unless you drive around with the clutches slipping for a long time it doesn't need a rebuild.

 

[trevvor]

After reading some of the posts from this site it sounds like when I had the tranny serviced the 1st time, they didn't put in the Mercon V. This probably led to slipping problem in 1st. It very well could have been loose valve body bolts but that's after the fact now.

It's after I had it rebuilt that the TCC problem has occured. And I'm guessing that it's TCC because it so subltle and well, that's what the rebuilder said it was - except he said it was normal for it to do that. It just doesn't seem right though.

OK, so those with 5R55E try this yourself. When on the freeway, just try and keep an even speed. Notice when you go up slight hills or when you barely accelerate, does it feel like there is a slight slip. Do you notice the tach go up about 100 and fall back. Not when you step on it and it drops out of OD, but when you slightly accelerate. It should be a smooth acceleration and the tach should not waver back and forth.

The shop that rebuilt my tranny said that this is how TCC is suppose to work and mine never worked right from the day my X was built. I find this hard to believe. Not only that, this is really annoying and I'm not getting very good mileage.

Give this a try and let me know what happens. I don't know anyone with an Explorer who could check this out so this would really be a good test. Thanks

 

[Coens]

I've had more or less the same symptom with my Ranger - momentary slipping in overdrive. All of the repair shops I approached assured me that the box needs to be rebuild. Somewhere in this forum someone exlained the procedure to adjust the friction belts (one of them has to do with overdrive). I did it myself in 10 minutes and the problem was solved

 

[mp223]

I am curious to see what happens as well. At about 95 mph I experience what you're describing to a degree, a rise in rpm and a slight loss in power. Exactly like the torque converter is unlocking.

I'm going to try adjusting the overdrive band on the transmission once I can pickup a in-lb torque wrench. The specifications are here: http://www.explorerforum.com/forums/showthread.php?t=158160

I also foresee a rebuilt valve body from Central Valve Bodies in my future.

 

[Coens]

Some feedback - lately I have been experiencing loss off TCC lockup (5R55E). The TCC would disengage, if I keep driving the same speed it would sort itself out after a couple of km's. If I pick up speed to about 150 km/h it would also function correctly.

The weekend I serviced and noticed a vacuum pipe at the brake booster is perished. Midas Spares gave me a 6 inch piece of 1/4" vacuum pipe for free, I fitted it and no more TCC disengage! Something in that electronic brain uses a vacuum input to make decisions for the box... Another symptom is that the brake booster didn't hold the vacuum anymore, i.e. when I switch the engine off, and press the brake pedal after a couple of minutes, the pedal would stop higher than normal, and when the engine is started it would go down to the normal position.

 

[Coens]

Spoken too soon - the loss of TCC lockup has returned. Now I'm trying to figure out which of the items I worked on caused the temporary fix.. can the disconnection and subsequent re-connecting of the battery somehow cause a "reset"?

 

[Coens]

TCC disengage downhill

Well after a couple of false starts it seems I have found the root cause of TCC disengaging on downhill.

Phoned a reputable auto shop here in Joburg, the technician's immediate response was "Faulty TPS". Not being one to throw parts at a problem, tested it this morning as described at http://www.easyautodiagnostics.com/ford_tps_explorer/ranger_tps_test_1.php. Turns out the TPS is fine, reading 0.98 V with closed throttle and 4.7 V with fully open throttle.

Continued to test EGR valve as per the same website - viola!... no response. Feedback stayed at 1.02 V, with or without direct vacuum applied to the valve. Took it out, and gunk has frozen the valve solid in the closed position. Remove the valve, filled it with penetration oil, and with vacuum and use of long nosed pliers, it came free after about an hour. Re-installed and took the Ranger for a test drive just now, it seems fine! Guess the final test will be the daily trip into Johannesburg tomorrow.

Thinking back about the way the TCC used to disengage, it makes perfect sense now (until it rears again!). Slight downhill, back off the throttle a little, not enough to go into "coast"; engine now running lean with resultant high exhaust gas temp, ECU compensates by disengaging TCC. The disengage never had an "immediate" feeling, like an on or off switch. Getting back onto the accelerator will cause exhaust temp to come down, and after a while get into programmed "safe" range.

Will report again after the work run...

 

[Coens]

TCC disengaging on downhill

Well Whadya know...seems your MAF sensor may be the culprit - cleaned mine and now it seems fine!
Check this site http://www.fordscorpio.co.uk/cleanmaf.htm

"There is mounting evidence that a dirty MAF sensor can cause gearbox malfunctions, such as reported incorrect ratio errors, loss of 4th gear or torque converter clutch (TCC) operation"