2005 Ford Mustang GT Automatic Transmission Problems

Hi All! I’m new to car talk and looking for a little advice. Sorry if this is a post thats been covered before, I didn’t see anything pertinent in my brief searches.

I’m a proud owner of 2005 Mustang GT, 4.6L with an automatic transmission. Intermittently for the last year or so (maybe once every 3 or 4 months) its been shuddering when in reverse. Today it ramped things up a notch. :-/ The shuddering was pretty dramatic when I was trying to back out of my driveway, I shifted into park for a moment, then back into reverse, and it seemed to be ok. Then when trying to back into a parking spot this afternoon at work (in a parking garage with a small incline) it lost power almost entirely in reverse, lightly pushing on the gas just caused the car to shudder and not move anywhere. I shifted into park, and then back into reverse and heard an audible “pop” (my windows were down, but they hadn’t been earlier so I’m not sure if this happened in the morning) and the car did not want to reverse. Rather than risk further damage I decided that it was parked relatively ok (90% in the space, eh good enough) so I stopped.

Obviously a trip to the mechanic is in order, but any idea what I should expect? or how much repairs will be (I’m in the Bay Area so I expect they’ll be a bit pricer than the rest of the county)? I’m not in a good place to shell out a lot of money, so I’m hoping the whole transmission doesn’t need to be replaced.

Thank you!!

No Check Engine light on?

If not, when was the last time the transmission fluid was serviced? If ever?


No check engine light is on. Pretty sure the fluid was flushed a couple of years ago, but not certain. I bought the car from a relative two years ago.

Suggest to start with a proper transmission service. Usually on most newer cars that means for the shop to drop the pan, drain all the old transmission fluid out, replace the transmission filter w/an OEM unit from Ford, refill using the manufacturer’s specified fluid. If this has never been done before, drive it a couple days, then do it all again. If that doesn’t solve the problem, report back here. On some newer cars this job is tricky, and needs someone experience to do it. Everything has to be perfectly level and at the correct temperature to get the refill at the correct level. They may need the Ford scan tool to do it correctly.

Will do, thank you!