Aboutautohelp Expertise On hands professional expertise in all aspects of Cadillac diagnostics and repair mid 1970`s thru 2000 year vehicles. GM certified in electronic fuel injection, Automatic transmission, Heating and A/C, and onboard vehicle computer diagnostics.
Experience Held over 15 GM certifications prior to retirement in 1989.
Organizations Prior to retirement held several ASE certifications, numerous Factory certifications.
Question QUESTION: I have a 1989 Cadillac Sedan Deville with a 4.5L in it. The car had 82,000 miles when I bought it. The transmission under morderate to heavy acceleration thunks at the end of its shift from 1st to 2nd. Under light to slightly moderate acceleration, the transmission "shudders" from second to 3rd gear. I did a fluid exchange (the fluid was still redish, not burnt) and that did not help. I added Lucas Transmission additive and that did not help. I did find that all 4 motors mounts were bad and replaced them. I have also replaced the modulator (which was not leaking but when removed the plunger just slopped around in it). The shudder is less after all this except when on a steep hill and down shifting at about 20mph it shudders quite bad until it kicks down. Any advise would be appreciated. Also, I don't know if this matters but, the car came from Florida and is in excellent shape so rust is not an issue.
ANSWER: IS or HAS the CHECK ENGINE light ever illuminated on the dash while driving the vehicle ?.
have you seen any unusual messages in the message display center ?.
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QUESTION: No codes except the idle control circuit and that was only when it was cold (below 40 degrees and would not come on again until the car sat over night and it was below 40 degrees the next morning). It is my understanding that the only electronics on this transmission is the TCC? Is that correct? The car also just passed an emission test with flying colors.
Answer If you are mechanicaly inclined or know of someone who is, You will need a DIGITAL VOLT/OHM METER, Simple electrical schematics, Test procedures and picture locations of the components within the system that is causing you problems of which can't be done on this website which only allows one picture.
I do not have a website so you will have to e-mail: onlineautohelp@msn.com
in order to obtain the information necessary to fix your vehicle.
