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Discussion Starter #1
Wifes car started acting up about 2 months ago. It has been parked awaiting parts this whole time.

When driving down the road and the car shifting into OD the engine would buck really hard. Eventually it started doing it on decel through all of the gears. (Now (after the motor mounts) sometimes on takoff it is still in OD instead of downshifting) My first thought was engine mounts. I finally got the money for them and put them in tonight. Took the car back out and drove it prolly about 20 miles and it started again.

Got it home and rechecked the trans fluid and it was really thin and dark colored (smelled a little burnt too) so I drained the trans. There was a magnet inside but it didn't have a whole lot of gunk on it, just a light film.


So the question is this:
Should it be ok and it was just due for a change or is the tranny going out?

Remember, it drives fine till it warms up and the car has 116K and some change on it with the original filter/ fluid (probably anyway)

The car has the 3.4 in it if that makes a difference.
Thanks
 

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neither, you probably have a solenoid problem or some other issues. I would take your car to see if there are any codes in the computer. Like go to Autozone or Advanced or whatever and they'll scan it for you. Then let us know what they see.
 

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Impala shifting problem

My 2000 Impala has the same 'hard shift' problem. Strange thing is, sometimes it shifts smooth, sometimes it shifts hard and jerky. Had the fluid changed but didn't help. I can tell when it is acting bad because I hear a whining noise before it shifts. I keep checking the fluid level and it seems ok. It doesn't slip when shifting.
 

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Discussion Starter #5
ok got the code. Yesterday was the first time it had come on in.

p0742-torque converter clutch circuit stuck on
How hard is this to fix? Where is it located? etc.

Thanks guys.
 

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well... usually its the torque converter cluth solenoid, or TCC. That's inside the side pan on the trans. To get to the TCC the valve body has to be removed, depending on the vehicle year, there's an updated valve body too. Its not exactly a job that can be done easily in your driveway. So the first thing I would do if I were you, is to check the main harness that goes into the trans. A lot of the time the harness rubs through at the bottom of the air cleaner box or on the bolt for the a/c dryer. Make sure the wires are ok there, if they are then the solenoid needs to be replaced. If you replace that, replace the shift solenoids and the pressure control solenoid.
 

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Discussion Starter #7
Pulled the air box and checked the wiring. It's perfect. So it looks like I'm pulling the trans. Any special tools needed to do this? (The last chev I worked on was my old 79 C20. I've been all Mopar since then and like to do my research when it comes to new projects) I have found an online diagram showing where the sensor is already, but how about prices?

Thanks again.
 

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You don't have to pull the whole trans out. You actually drop the subframe down and let it hang a bit, till you can take the side cover off. You have to know what your doing though. Cause you can't lose the balls in the valve body, if you lose them you have to get a whole new valve body. that's really the only thing you need to watch out for, and try not to ruin the gasket. Its reuseable.
 

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Discussion Starter #10
Ok guys. Here it is all tore down. Please point me in the right direction, but I do believe the TCC is the sensor at the very bottom left side?

Thanks guys.

 

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Discussion Starter #12
ordered some more solenoids today. Any idea what would also be causing the 1-2 shift delay/slip? It only had that one code for the TCC and everything had run just fine before this. Would the TCC cause the slip/delay?

Sorry to be a noob about this, but FWD auto trans. aren't really my specialty, especially when there are a whole bunch of sensors in them. :rolleyes:
 

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Discussion Starter #14
Got them replaced, put back together, etc. and reset the battery but the CEL was still on. We drove it for an hour and it went off and stayed off.

Sweeetness!

Thanks for the help!
 

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Just gonna throw this out there,but a trans flush would have more than likely got rid of the issue.

When I have a vehicle come into the shop with a sticking solenoid it's usually due to dirty fluid allowing the solenoid to bind up because of deposits.
A complete flush with the machine backflushes through the filter and there is no need for a filter change.

For $75 it's alot cheaper then replacing solenoids.

So if you have dirty fluid,and getting codes for sticking solenoids then do a trans flush first.
Trans flush should be done every 75k anyway imo.

disclaimer..i'm not a trans guy-I pull em and install em but I don't diagnose or pull it apart unless it's solenoid/valvebody related. I'm the driveability/electrical tech for the most part-so I get em before the trans guy usually and diagnose the code if I can.
If I can't diagnose it I send it to him as I have no interest in trans repair or diagnosis-too dumb for that technical stuff.
 

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Just gonna throw this out there,but a trans flush would have more than likely got rid of the issue.

When I have a vehicle come into the shop with a sticking solenoid it's usually due to dirty fluid allowing the solenoid to bind up because of deposits.
A complete flush with the machine backflushes through the filter and there is no need for a filter change.

For $75 it's alot cheaper then replacing solenoids.

So if you have dirty fluid,and getting codes for sticking solenoids then do a trans flush first.
Trans flush should be done every 75k anyway imo.
First of all GM says every 50k for a trans flush. Second, the trans flush is not a guaranteed fix, whereas replacing the solenoids is. However, I do believe that a trans flush is a great idea to do after the solenoids have been replaced, but that's optional.
 

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Well,as a technician it's my responsibility to repair the root cause of the symptom. Replacing solenoids without diagnosis is called parts hanging-our customer's don't like that.
Symptom->System->Component->Cause
TCC code->TCC->Solenoid->Fluid

Half the time you can correct the faulty condition-and not replace a part.
I can site examples all day that include 02 codes,MAF codes etc..

Replacing solenoids=$$$$$$$
Flushing trans when you have dirty/burnt fluid=Common sense,cheaper option and basic maintenance that is called for anyway.

50k-75k,whatever. Not my fault he can't read his owners manual.
I go by my own maintenance schedule personally-not the manufacturers. Manufacturer doesn't factor in driving style,conditions etc..
Sometimes you can go longer-sometimes you need it sooner.

As for guarenteed fix-I doubt it.
The dirty fluid is still cycling through the system-that's a guarenteed temporary fix I guess is what you mean.
Till it binds up the solenoid again.
Optional??? WTF?
I'm guessing you replace alot of parts on your cars?
 

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no, as a technician, I replace the common failure prone parts. TCC's, and pressure control solenoids are common problems, especially with the 4T60 and 4T65 transmissions. Some even have updated valve bodies as well. But you being a technician probably already know that there are bulletins out for these issues.
Also what do you say to your customer after you flush the trans and the problem isn't fixed? Or you flush the trans and all of a sudden the trans slips like crazy and makes the problem even worse? A flush is not a method of repair. It is preventative maintence. Or a "try me"
 

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no, as a technician, I replace the common failure prone parts.
We call these people mekanik's,not technicians-technician's are trained to find the failure and repair it-not hang common failure parts until it's fixed.

If that were the case then being a Ford technician I would reccomend a new car everytime a customer came in with an issue.

And our TSB's tells us how to diagnose to see if the bulletin even applies,it does not tell us to simply start hanging parts.

On something like this I would tell the customer that a flush should be tried first,since it's needed anyway. But they would know under no uncertain terms that the issue could still lie with the solenoid or valvebody itself.
And I can easily see if the solenoids are sticking afterwards by doing a test drive watching solenoid and pressure pids.

Not trying to argue with you-if your a GM tech then you definately have more knowledge in this area then me.
But your way of doing things boggles me,I very rarely replace any part until I can actually see the problem in front of me.
Not always possible,but I hate the idea of a customer buying unneeded service's/parts.
 

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But what if you flush the trans and it makes the condition worse? Its been known on occasion to happen. Where as you could've saved all the trouble by replacing the parts then flushing. And you look like an idiot cause you couldn't fix the problem first. Yes you can check pids and whatnot. But if your flat rate, screw that, just replace the part and flush. You know the problem will be fixed.
 
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