My 97 Bonneville SE shudders when the torque converter clutch engages. My question is, can this be replaced without tearing down the whole transmission, and can running it like this damage anything else? Any info or ideas on what to do about this is greatly appreciated!

I'm not sure when the fluid was changed, I just got the car a couple of days ago. The fluid looks clean and doesn't smell burnt. My friend that I got the car from said the car has been doing this for a long time. It shifts great, it'* just when the tcc wants to engage it vibrates like crazy.

Is this maybe an ignition related problem? Does it shake the whole time it is in lockup or just as it is engaging? If it does this the whole time it is in lockup then I would suspect the plugs, and wires should be looked at. Did you happen to find out when the last tune-up was done? If the plugs and wires are recently replaced I would then move on to the coil packs, ICM, and also the injectors. There is an article in Tech Info to check the coilpacks, and I would clean the contacts on the ICM while they are off. As far as the injectors go there are rare cases of bad or wrong injectors which I had. When I bought my 93 I had a bad bucking in lockup and it turned out to be that someone put in a completely wrong injector. I switched the injector with one from the yard and it ran like a dream. Welcome to the club.

The car was tuned up 10/07. The shuddering occurs while it is trying to engage. It seems as though it is engaging and disengaging like it can't make up its mind, or maybe it can't fully lock. The rpms will go up and down if it does it slow enough, but usually it makes the car vibrate.

Everything in the ignition system seems fine. Is there a way of isolating the tcc or disconnecting it to see if the problem stops?