My vehicle has 112k miles. It feels like the transmission is clunking when cruising or sometimes when slowly accelerating. The engine seems to be running smoothly and I don't sense any slip in the transmission. It used to happen only occasionally, but the other day it was clunking badly and the wrench light came on. The wrench light went off after shutting the engine and restarting. OBDII scanner showed no codes. So far, the clunking only happens when the engine has reached normal operating temperature. My best guess is that the transmission solenoid pack could be bad. Does anyone have any better guesses?
I have enough mechanical knowledge and the tools and equipment to do almost any work myself, including replacing the transmission, if necessary. I know the vehicle is not worth anything, but it's in good condition and runs well save for the clunking. I would prefer to keep it, especially since I will be saving a lot of money by doing all the work myself.
I'm providing this update in case anyone else should run into the same issue. I fixed the problem by replacing the transmission solenoid pack. Since I had to pull the pan I also changed the trans filter.
The old fluid was dark, but did not have any burnt smell. There were no metal shavings nor clutch debris in the fluid or in the pan. The magnet had what looked to be a normal amount of residue, given the mileage. I took apart the original solenoid pack to inspect the screen and it was clean. My opinion based on these observations was that the transmission itself was fine. If the fluid had a burnt smell or if there was a lot of debris in the pan in fluid, I probably would have replaced the whole transmission (Autozone has one for ~$2,000 and it comes with a three year warranty).
Transmission now shifts smoothly. The clunking is gone.
is the clunk when it's shifting gears? if you manually select a gear does it clunk?
solenoids don't clunk I'm afraid, and it might be cheaper to buy a newer vehicle than a new tranny.
Thank you for the reply. I should add that only the wrench light comes on. The check engine light does not come on. Also, the clunking seems to occur when the transmission is or should be shifting into one of the overdrive gears. When I step on the gas, it seems like the transmission does not want to downshift. However, it will downshift if I manually move the selector. It does not clunk while manually remaining in the lower gear.