Matticus
Well-Known Member
I recently put a used transmission in my 2012 Expedition EL. The transmission came from a reputable place (LKQ) and had less than 50,000 miles on it. Not long after it was put in, I started to notice that there was an occasional "clunk" from the transmission as I was slowing down, right when the car would hit 25mph and shift into what I think is 3rd. Within a few months it was doing it more often and, sometimes, the noise was fairly loud and you could feel the car lurch slightly. While it will do this at any temp, it seems to do it much more as the transmission temp gets up 175 degrees or higher. It will happen when I am applying the brakes or just coasting down to 25mph. Otherwise, the transmission seems to work just fine.
The transmission is still under warranty from LKQ, but trying to get the shop I had install it to diagnose it properly has been ridiculous (story for another time). They are now saying they think it is a differential problem. That just doesn't seem logical to me - how could it be a diff problem when it happens so predictably at the exact same speed and coincides perfectly with the transmission shifting down to 3rd? Anyone have some insight?
The transmission is still under warranty from LKQ, but trying to get the shop I had install it to diagnose it properly has been ridiculous (story for another time). They are now saying they think it is a differential problem. That just doesn't seem logical to me - how could it be a diff problem when it happens so predictably at the exact same speed and coincides perfectly with the transmission shifting down to 3rd? Anyone have some insight?