torque converter woes?

[mistertonylee]

Hi. New to the forum, so please humor me. My car has started to shudder when decelerating. It happens at 20 mph and stops by 12 or 15 or so. This is about the point of the 3-2 downshift. 4-3 and 2-1 are fine. It seems like the torque converter is not disengaging as it is supposed to. I checked the switch at the brake pedal, and it seems to be fine. Is there a way to wire it to stay off so I can test it?
Interesting note: The only time it doesn't happen is when stopping up a hill, and even then it does it sometimes.
The tranny was just flushed, so I know that's not the problem.

Thanks

Tony

[athflying79]

I'm certainly no expert, but if you search posts about flushing the tranny.....you will find that often times doing so brings up a myriad of problems. So if you had no problems before the flush and now afterwards it is acting goofy, I would say that is part of the problem.

[mistertonylee]

Actually, I had the trans flushed in hopes of fixing the problem. It was acting up before the flush, and is doing exactly the same after. It seems electrical to me, as if the torque converter is being forced to disengage by engine speed instead of already having done so by a switch. I ordered a brake switch and will install when I get it. Hopefully that will fix it. If not, it's only $25 with shipping.

[632 Regal]

have the entire driveline inspected, could be the guibo or center bearing support. they do wear and get sloppy.

[dacoyote]

Valve bodies.. maybe....

[mistertonylee]

i know it's not the guibo since my car (535i auto) doesn't have one. i'll check the center support bearing, but since i don't have jack stands it'll be tricky to get under the car.

[mistertonylee]

also, thanks for the quick responses. i tried another forum and was sorely dissappointed. but this one rocks!!!!

[mistertonylee]

is there any way for a guy like me (plenty of technical common sense and common tools but little else) to test the valve bodies, or would i have to take it to a shop?

[632 Regal]

haha

also, thanks for the quick responses. i tried another forum and was sorely dissappointed. but this one rocks!!!!

it is possible for the valve body plate to wear to the point that the balls are sticking from over large holes. You have a ton of mileage on it, so other than the center support this is what I would do next.

[mistertonylee]

okay. sounds good. now how the heck to i check that? i understand engines, suspension, most electronics, etc, but transmissions confuse the heck out of me.

also worth noting, the trans was rebuilt by previous owner (actually a professional shop hired by owner) at around 180,000, so i was expecting to get that much out of it without problem.

also, does anybody know how to create a short circuit to make the torque converter release so i can test it?

Thanks
Tony