well, my Torque Converter Solenoids locked up last night. Going down the freeway just fine, get off the exit ramp, get to the light - as I slow down, car gets jerky, then stalls as I stop. dmanit. at first I thought something went wrong with the motor - put it in Neuttral - start it. starts fine. rev it. rev's fine. everything smooth. ok. put it in gear - stalls. damn. I've heard of this - its that damn solenoid. ok. start it up again, rev it to 3000, then drop into drive. little tire squeel, and away I go. coming up on next light. it's red. damn - turn green is all going thru my head, anyways - it dont. I come to stop. no problem. the solenoid let go. hooray!
now, the questions are - is this gonna happen more & more? and how hard is changing the solenoid?

Yes it will likely keep happening.

Not rocket science to change. Time consuming and awkward. It is under the side cover. Replace the third gear switch while you are in there.

Note: the solinoid is polarized. It matters which wire goes where.

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11-Sept-01, The day the world as we knew it ended.

so the trans dont have to come out - good!
hasnt happened again. the car sat for awhile before I took it out last night, so maybe it just got sticky....
a great time to start looking for a 5-speed or maybe a trans with overdrive

Just to be safe, why not unplug it so it *can't* lock up on ya... If memory serves, it's a whitish square connector on the driver's side, by the vertical pan that when you pull it off will make a mess of you.

If it gives you problems, Just unplug it until time is available to fix it. you'll get lousy fuel mileage, but should last awhile. Just try not to drive at too high of an RPM. It's a plug, visible on the trans. There are two plugs. One with a bunch of wires. Another with a few.. It's the plug wityh only a few wires.. Hope this helps..........anyone know if leaving the switch unplugged for too long does any damage? erockrocket

yeah, if it sticks again, thats what I'll do, unplug it. shouldnt hurt, I dont do much freeway anyways

quote Originally posted by Pyrthian: yeah, if it sticks again, thats what I'll do, unplug it. shouldnt hurt, I dont do much freeway anyways

This should be okay for the short term. I disconnected mine for a while until I could find the time to buy parts and install to fix the problem (maybe 200 miles total). I wouldn't keep it disconnected forever, though. All that overheated A/T fluid can't be good for the tranny internals, especially during those mild, breezy, don't-need-air-conditioning midwest summers (ha ha).

Parts may be cheaper on gmpartsdirect.com, but the prices I paid in '99 are:
8652910 A/T Filter Kit $24.92
8678169 Gasket (Side Cover) $7.84
8689901 Valve (TCC Solenoid) $38.80

Good luck!

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You can leave it unplugged indefinitely with no harm to the tranny. You don't give any details about the year or anything, but I do know that certain years have a HUGE bracket in the way of getting the side cover off. I just remember......don't remember what it does or how hard it is to take off, but it covers about 1/3 of the tranny. Good luck!

Phil

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GTDude
OVER 27 years GM experience

I think you are getting a little bit of misinformation in a few of the posts on this subject.

I've had the same problem on 2 transmissions. You've already described the symptoms, let me add some alternatives/observations.

1. The solenoids can fail with the TCC locked or unlocked. Each of the failures in my cars was with the TCC locked(same as yours)
2. The solenoid failures will get worse and are more likely to occur with the transmission hot. If you are willing to wait long enough for the tranny to cool off, it may function properly again for a short while, or long enough to nurse it home.
3. The quick simple solution is to unplug the square connector on the drivers side of the tranny. This will keep the ECM from locking up the TCC if it is currently unlocked. I drove mine with the TCC unplugged for nearly a year and see much of a downside. There is no performance change at speeds below 40mph, and the 200rpm increase of engine speed above 40 mph actually improved acceleration. True, the engine noise was slightly increased, but in all fairness I saw no perceptible change in gas mileage. (Most of my driving was on the freeways in Houston, as opposed to high speed driving on country roads.)

4. Lastly, GTDude is correct. In 88, the transmission and engine support brackets were redesigned to accomodate the new 88 engine cradle. The new transmission bracket on the 88 automatic, completely covers the transmission cover that needs to be removed to gain access to the replace the solenoid. Sorry, I haven't had to change one of these yet, but it looks like it could be a royal PITA.

My recommendation, just unplug the TCC connector and that fixes the problem, don't worry about it until you have some really good reason to drop the engine cradle.

Good Luck,
G2

The TCC can be left unplugged but you should keep in mind that it is a SLOW death to the transmission. The bottom line is it will be slipping a little bit when it should be locked. Very few people will realize that their transmission failing in 5 years or more was caused by something done so long ago. Unplug it to test it and then in the near future replace the sylinoid, even if it is a tough job.

The monomount, with it's giant bracket, is used on the automatics after 86.5 on the L4. I think the V6 may not have it.

It's a pain in the a_s but not a big deal. Just support the tranny with a jack and spread the load across the pan with a section of 2x6. The wood should be long enough to span the width of the pan plus a couple inches. The pan can take the load but only if it is spread out.

Make sure you soak the studs on the mount with penetrating oil. If you cant get the nuts off, split the nuts. That mount is getting hard to find and expensive when you can find it.

Exactly what if anything will happen to the tranny by driving without lockup depends on where you drive. Short term it isn't likely to do any damage. Many city TH125c's spend most of their lives unlocked. Lockup was added to TH125 and other 80's GM transmissions mainly to satisfy fuel consumption targets.

I wouldn't recomend running it unplugged any longer than needed but you certainly can't drive it with that hanging up. Beating up the tranny with a hung TC lock won't help it any. It also becomes a safety issue since stalling the engine also effects the brakes (loss of power assist.) and if it happens in heavy traffic you could easily get run into.

Don't "unplug it and forget it!" It's not that hard to replace. Mine is an '88 GT. It took about four hours, and some choice words to complete. You don't have to remove any brackets either. You will be happy with the results.

quote Originally posted by theogre: The monomount, with it's giant bracket, is used on the automatics after 86.5 on the L4. I think the V6 may not have it.

Correct. It's just the 4 cyl.

Here are a couple of links that detail the replacement procedure.
http://www.kichline.com/chuck/fiero/TCC.htm
http://home.t-online.de/home/O_Scholz/tcc.html

FWIW, the TCC solenoid on my Formula went out over a year ago. I unplugged it, and it's still unplugged. Going to replace the solenoid when I drop the cradle for some other work. I don't really drive the car much, so I'm not too worried about it. My gas mileage did drop, though.

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Raydar

88 3.4 coupe. A work in progress.

Out of my mind. Back in 30 minutes.

When mine locked up on me, I wasn't able to remove the plug from the tranny (roadside failure). If you remove the speedometer connector, that will prevent the computer from locking the solenoid. Of course, it will also disable your speedometer, but it is useful for "limp-home" mode.

It's a good limp mode. Note that it will also set an error in the ECM and you'll want to clear that out later.

just a follow-up
hasnt happened again, hoping it was just a freak thing from sitting for a few weeks. I can see its working, the small tach drop around 40 mph. (ADS chip moved the lockup to ~40)

I had the same symptoms on my 88 auto 2.8L.
I ordered a replacment TCLS from the Fiero Store (I had some other stuff I was ordering). I think it was around $30.00 and came with the new gasket.

It was not too hard, a little messy though... There's about a quart or so of tranny fluid on that side of the 125. Beleive me, If I can do it, anyone can. There was one or two 'annoying' bolts to get at, but the most time consuming thing was scraping all of the old gasket material off! Uugh, I thought my arm was gonna revolt on me!

I did not know about Ogre's suggestion on the 3rd gear switch thing. I wouldn't know what to look for. He is wise in many things Fiero.