Well, I had some suspicions of my own about what was causing my TCC shudder, and I finally did something about it. Post fact, I’ve gotten rid of probably at least 90% of my TCC lockup issues. Everything is (almost always) nice and smooth now – even while accelerating with the TCC engaged.

So what did I do? New battery. That’* it, that’* all. I started thinking about it during a class on the 4L60 where the person teaching the class mentioned that a lot of strange things can happen in an electronically controlled tranny when you can’t supply a constant voltage because a battery is dying. Well, I finally had enough of my old battery yesterday (car barely started and was stumbling at lights trying to keep the battery charged) and picked up a new one.

I noticed the change right away – things were suddenly smooth and quiet. If you’re trying to feel it, you can still feel the TCC lock and unlock, but it’* much more smooth than before. In about 100 miles of driving since I put in the new battery, I’ve only felt the TCC shudder like it used to a few times.

Now, the disclaimer (have to have these so people don’t get mad at me) – this solved my particular problem (most of it). But the fact that there’* still occasionally a problem means that (in my case) it’* not just the battery. Which means that in your case, it may have nothing to do with your battery… so please don’t get mad if you go out and replace your battery and don’t notice a change – that said, those of you with TCC issues should start thinking about how old your battery is… it might have something to do with it.

That'* interesting. It'* always best to eliminate the obvious.

interesting........

Shouldn't your alternator be supplying the voltage though? Replacing the battery would only be a coverup for a bigger problem if that'* the case...

The battery is more than a "storage device". The alternator is a support system for the battery, everything electrical still needs the power the battery provides. In the "old days" you could disconnect the battery and the car would still run, but that could be a fatal mistake in a newer car. Look at the power requirements of our cars, and all the computer controls, and what happened makes total sense.

My thoughts too. Is your alternator getting lazy?

no and no.

the alternator'* job is to charge the battery - if the battery won't accept that charge well, your alternator can be running perfectly and it won't be able to supply the constant voltage that your car wants to see.

in any event, i have a brand spankin new alternator on there (<l month). with the new battery, everything is peachy. today on the way home I intentionally did accelerations while under TC lockup @50 mph, and it'* nice and smooth.