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Converter shudder....PLEASE HELP

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Old 12-06-2003, 10:07 PM
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Default Converter shudder....PLEASE HELP

Hi guys. This is my first post here. I have asked this question on several forums and can not get a straight answer from anyone.
I have a '96 Z28 A4. Ever since I got the car in March, the car shudders while coming to a stop, then jerks really hard when im almost totally about to stop, and thats when the shuddering stops. It does not do it in neutral. I'm thinking the converter is not fully unlocking, and when the car is almost fully stopped, it unlocks and thats when it jerks hard. Can someone please help me out? Thanks.
Matt
Old 12-06-2003, 11:12 PM
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Thats exactly whats happening
Old 12-06-2003, 11:22 PM
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Ok. Thanks. So I guess I better go buy a Vigi huh?
(seriously though) is my only option to replace the torque converter?
Old 12-06-2003, 11:31 PM
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i would probably replace the TC anyway but you might have a PCM problem where the computer isnt recognizing your speed, gear choice and braking force....the TC should unlock THE SECOND the breaks are applied....is this a stock converter???? if so ditch it and buy a vig anyway....you wont be sorry...good luck
Old 12-06-2003, 11:45 PM
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It does unlock when I tap the brake, but I don't think it's unlocking fully.
Old 12-06-2003, 11:53 PM
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then you have a computer problem would be my guess.
It should unlock when you hit the brakes so that is good..I would say swap your computer with someone elses and try it
Old 12-06-2003, 11:54 PM
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When it starts to shudder, put the brakes on just a little bit and keep the gas on and see if the shudder goes away
Old 12-06-2003, 11:56 PM
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It shudders while I have the brake pedal pressed down....not when my foot is on the gas.
Old 12-06-2003, 11:59 PM
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Just trying to understand..but you said it unlocks when the brakes are applied in an earlier statement

Last edited by Hugger SS; 12-07-2003 at 12:08 AM.
Old 12-07-2003, 01:33 AM
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Yes....i can see/hear the RPM's rise if i tap the brake gently, but it shudders when im coming to a stop after cruising.
Old 12-07-2003, 02:51 AM
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Sounds like a bad TCC PWM solenoid, or a restriction in the fluid circut that is not allowing the clutch to disengage. Could also be a PCM problem but that's not very likely. If it's not internal the most likely cause is a wiring problem, such as a pinched wire, etc.
Old 12-07-2003, 02:59 AM
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Also check the operation of your brake lights, make sure the switch is functioning. If you have access to a Tech2, see if the BCM is recieving a signal for brake pedal apply.

By the way, does it also happen if you shift to neutral during braking?
Old 12-07-2003, 03:07 PM
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It does not happen if I put the car in neutral. I highly doubt it's the PCM because it happened with my old PCM, and still happens with my madz28.com custom tuned PCM (I bought a whole new PCM, I still have the old one). How should I go about checking the wires? How hard is it to change the solenoid? Do you have a part number?
Thanks
Matt
Old 12-07-2003, 09:24 PM
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The solenoid is a very easy change, just requires a pan drop. Sorry I don't have a part # handy.

As far as checking the wires, look for obvious signs first. Is the harness rubbing somewhere? Stuck to exhaust or header components? Pull the connector off the trans (Big grey one on pass side). Is there corrosion? Beyond that electrical diagnostics become more difficult.

If I think of any other simple tests you can make I'll let you know
Old 12-08-2003, 07:45 AM
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Alright thanks.....what about those fluid additives? I remember someone mentioning they had converter shudder and they added "Transmission fluid friction modifier" and it got rid of it. My friend thinks I should run Transmedic through it.....what do you think?
Old 12-08-2003, 07:48 AM
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Is this the part I'm looking for?

51873
TCC (PWM) Solenoid 1995-on $35.85


from:

http://www.drivetrain.com/4l60e.html
Old 12-12-2003, 01:19 PM
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Also, my dipstick keeps popping out of the tube. I press it down all the way then after I drive it comes out about an inch.
Old 12-13-2003, 10:44 AM
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ya, there is an additive that Midwest sells for their converters...I just received it from them...They say it helps, but I haven't give it enough time to work yet
Old 12-13-2003, 08:14 PM
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Originally Posted by flyinZ
ya, there is an additive that Midwest sells for their converters...I just received it from them...They say it helps, but I haven't give it enough time to work yet
Cool, let me know how it is. If it works, I'll get some ASAP. I'm changing my tranny fluid in a week or so.
Old 12-13-2003, 08:41 PM
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I had an old Olds beater that I put some of that snake
oil in and within the week the trans quit. I would stay
away from anything that claims to have "seal-swell" or
seal conditioners, their idea of conditioning is softening
and swelling them up but this also weakens them.

Dunno about the friction modifiers but the juice I put
in that was supposed to have different friction modifiers
(B&M) modified it so my TCC squealed like a pig. Might
just start off with a straight fluid (Dex) & filter change.
When's the last time, anyway?



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