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Won't shift


Guest p38nut

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Sorry to hear you have a problem with your TC. There are a lot of guys on this site that will be glad to help you, like they did for me. But, they will need more info from you such as transmission type, Vin # and information leading up to your problem. Such as how did the problem occur... all of a sudden or something slowly over time. I hope you get back on the road soon!

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16 hours ago, p38nut said:

My '90 TC, 3.0l V-6 won't shift out of first gear.  Fluid is correct.  Any suggestions?  Thanks.  Mike

Mike, there is a diagnostic connector under the dash, sort of right above your left knee when you sit in the car. It is on the other side of the fuse cover as I recall. You need to take it to someone like Aamco who should diagnose it for free, at least they use to. They can then tell you what area of the transaxle is the problem. Often this sort of thing, called 'limp in mode' occurs when there is an internal problem.

Let us know what they tell you. When you drive it next time, use D, NOT OD. Your shifter may read differently, just NOT the first forward 'notch' on the gear selector.

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Being as it's a V6 car it has the A604/41TE "Ultradrive" transaxle.

 

Most likely it's not stuck in 1st, but rather 2nd. That is the default mechanical forward gear that can be achieved with that transmission.

 

There are a LOT of reasons that the TCM (transmission control module) could send the tranny into limp mode. It could be something as simple as a bad sensor, or something as bad as a broken OD snap ring (very common on the older units) or a broken apply piston inside the front basket.

 

As others have said, it needs to be hooked up to a competent shop's diagnostic computer to see what's going on. Besides obvious fault codes, the CVI nnumbers (basically a number that represents the internal clearances of the clutch packs to the computer) are something to be aware of. Obviously the closer they are to the middle of the range, the better (or slightly tight). 

 

Something you can try yourself at home is to reset the system and attempt to do a "quick learn" on the TCM. The caveat to this is that you will clear any codes the TCM might have stored that could help the shop determine what's wrong with the transmission. The upside to it is that it might get the car back to being a bit more driveable in case you need to drive it further to a known good shop to really check it out.

 

To do a "quick learn": (disclaimer, I tried to look this up before posting, but didn't find it right away. This is from memory and I haven't done it in many years. I *think* it's detailed in the FSM.)

disconnect the battery for ~30 minutes then reconnect it

start the car and cycle the shifter between all of the gear selections and "park" (it will probably engage the gears a little harsh, this is normal)

you need an empty road you can get up to about 60mph on and have room to stop

put the car in "OD" and accelerate up to roughly 30mph at about 1/4 throttle letting the transmission shift to 2nd (but not 3rd), then slow down enough to get it to downshift, but not stop.

repeat ~10 times

you will then increase your speed up to where it shifts to 3rd with the same procedure

work your way up to 3/4 throttle in this same manner.

 

Once you are done, what you have effectively done is "taught" the TCM the internal clearances in the transmission so that it can shift correctly.

 

Now, if the transmission has a sensor issue or an internal problem, this probably won't work.

 

The last A604 I had R&R'd back around 1998 was ~$1800.

 

There ARE updates, TSB's, and other things that *should* be done. I know one is that there are new sensor pigtails that should be installed. The new OEM solenoid packs are also much better than the old ones. The aftermarket has several kits to help improve shift quality and increase longevity. The biggie is seeing if your TCM can be "reflashed" with updated programming.

 

I know that's a lot to take in, especially if you aren't familiar with these transmissions. I also know it sounds absolutely like a nightmare. The truth is, it's not any worse than any other modern electronically controlled transmission. As someone else pointed out, Chrysler continuously improved the transmission until the end.

 

One thing I *highly* recommend is once you figure out what's wrong with the transmission and you get it fixed, install an auxiliary external aftermarket transmission cooler. Because of the way these transmissions work, they can really heat he fluid up. While the ATF +4 fluid is a fully synthetic fluid meant to deal with those conditions, it doesn't hurt to help it out a little. You can choose to bypass the internal radiator transmission cooler all together, or tie it in series. Personally, I eliminated the radiator cooler. My reasoning was that I then no longer had to worry about possible fluid exchange in case of a failure. 

 

I hope this helps some and I wish you the best of luck!

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Reaper1 certainly had it down to the last detail. Very well written. I didn't wast to DEFROST the iceman with such descriptive detail.

BUT, iceman be sure that your transaxle has only ATF+4 fluid installed, no matter who does the repair.

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Reaper1 certainly had it down to the last detail. Very well written. I didn't wast to DEFROST the iceman with such descriptive detail.

BUT, iceman be sure that your transaxle has only ATF+4 fluid installed, no matter who does the repair.

Since you live in Florida iceman, I can agree with the elimination of the factory radiator transmission cooler, but you guys who live where the snow sticks to the ground, better put the coolers in series, external cooler first to receive fluid from the trans and then through the factory cooler. 

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Reaper1 certainly had it down to the last detail. Very well written. I didn't want to DEFROST the iceman with such descriptive detail.

BUT iceman, be sure that your transaxle has only ATF+4 fluid installed, no matter who does the repair.

Since you live in Florida iceman, I can agree with the elimination of the factory radiator transmission cooler, but you guys who live where the snow sticks to the ground, better put the coolers in series, external cooler first to receive fluid from the trans and then through the factory cooler. 

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