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Transmission Problem on Chrysler 300c

Hello CarTalk Community,
I have an '05 Chrysler 300C AWD with approximately 65k miles. The transmission makes a distinct clunking sound when downshifting and I am seeking advice about the cause and solution. For example, I live on a hill and when I slow down at the bottom of the hill the car will downshift and there is a clunking sound. This happens frequently when I am slowing down. In the past year the transmission quit 3x, in all cases the car would start and operate fine but would not go into gear - it would idle but nothing would happen when I put it in gear. The first two times the dealer kept the car for several days and made various adjustments and the car eventually worked again. The third time the Torque Converter was replaced, but the clunking noise continues. What do you think? Any suggestions? Thank you.

<> Any “Check Engine” Light Illumination ? Diagnostic Trouble Codes ?
<> 42 RLE Transmission ?
<> Did The Dealer Mention Their Checking The Solenoid/Pressure Switch And Harness For Signs Of Moisture Or Corrosion As Per Chrysler TSB (Technical Service Bulletin) 21-009-05, Written For Technicians ?

The bulletin outlines a problem found on some 03 - 05 Chrysler models, including 2005 (only) 300/Magnum vehicles and outlines diagnostic and repair procedures if a problem exists.


Thanks for your thoughts. I’ll look into those issues and comment further if appropriate.

The 300C does not use the 42 RLE transmission. It actually uses a Mercedes transmission which is also used in AMG Mercedes vehicles and other high-performance models. At the time the “Hemi” version of the 300 was conceived, this was the only 5-speed transmission available in the parts bin that could take the torque of the big V8.

You have the AWD version of this car, so there are more drivetrain components than the RWD cars. Are you sure the clunking is coming from the transmission? It could also be a weak transmission or transfer case mount, or bad U-joints or CV joints. Does it make a similar clunk when put into reverse? Has the fluid been changed recently and the correct fluid used? (Genuine Mopar transmission fluid, not someone else’s fluid with an ‘additive’ package)

If the problem is in the transmission, only a competent transmission shop familiar with these (avoid AAMCO) or a dealer is likely going to have the tools and knowledge to diagnose this. You’ve already been to the dealer. Unless you have some warranty arrangement with the dealer, maybe it’s time to try a different dealer or an independent transmission shop.

Here is a search for your problem from a 300C forum–there are people with similar problems–maybe one has the answer or can give you an idea where to look: