First off, this is BS! My transmission has issues at 54,000 miles?!! Since learning to drive back in 1986, this is my 4th Mustang and 2nd GT. The first was a 95 GT auto and it's transmission needed a refurb at 58,000! My respect for Ford's auto transmissions on the Mustang GT is getting pretty banged around right now. With regard to my current 2006 GT, it started showing signs of clunky hard shifting in the 2nd gear. It would go through the 1st gear fine always, then sometimes when trying to shift to second, the engine rev would go way up and I could see it on the tachometer as well. I would have to quickly take my foot off the gas to get to go down and shift. In freeway stop and go traffic, when everybody would speed up as if things were flowing again "traffic wise", only to then abruptly stop, the shifting would be very clunky and un-smooth when picking up speed again. Also on those sudden stops, the shift down would be very clunky and you could really feel and hear it in the back towards the rear.
I take to it longtime auto-repare shop of some 40 years with the family. Very reputatable! They check it out and then take it to one of their recommended transmission shops, which has been in business since 1981. From what they have told me so far, it needed a valve body and the case needed to be redone. I'm not sure what else as I'm driving it around and will get back with the shop on Monday.
Anyhow, the first thing I notice since Friday is that upon startup, there's a low moan on that was never there before. Not like the high pitch whine I've heard on transmissions, but a low frequency moaning whine, that seems to get a little better driving it. You hear it best in the cabin as oppossed to outside or with the hood up. So that already doesn't sound right to me. But until coming back from work just now, the car seemed to shift great. Except for the new low sound, the car shifting great.
What happened coming home from work is something the car has never done, let alone any Mustang I've ever owned. I was first at a stop light, with cars behind me. When the light turned green, I put my foot on the gas only to hear the engine rev up, but the car went nowhere! I gave it some more gas and still nothing. I took my foot off the gas completely, tried again and then it started to move. So it was like the tranmission wasn't even engaged. WTF!
Anybody have these sort of issues with there 2005+ Mustang. Any thoughts about what could be going on? I mean, the tranny shop was very busy and had the car for almost two weeks. They gave it back twice to my mechanic for drive testing only to have him send it back because he didn't like the way it was shifting still after the work they did. To say I'm pissed and stressed out by all this is an understatement. Again any thoughts or suggestions. Thanks.

 

Slipping bands, particularly the low/reverse band, is my guess.

http://iihs.net/fsm/?dir=242&viewfil...By Symptom.pdf

From this main branch of the shop manual:
http://iihs.net/fsm/?dir=239

You can look for your symptoms and see if any of the things apply to you, and if you or someone can perform the required checks... and besides the PCM, and pressures, the bands are the very next check.

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I'm.. not terribly convinced this transmission shop is a good one. Regardless of your general mechanic's instincts and/or track record with it, it sounds like this 5R55S is just not their cup of tea... and you should maybe get it back and take it to a dealer.

I say it's the band. But it could be various things.

That they've had it twice now and still don't have it right makes me say 'get it out of their hands.'

And I'm just... not terribly convinced it's the valve body. And the *case* needs work?! That's... well, that's a new transmission, isn't it?

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And if all of that were true... you need to learn how to drive, because you're killing transmissions with your bad habits, man.

/not really...
//Well, what do I know, perhaps really.
///Nah, surely not...

 

I had my solenoid pack changed out recently 06 with 65k on it. It was upshifting hard but always worked. Yours sounds like it needs at least a tq converter, but I'm not a specialist by any stretch

 

sounds almost exactly what my trans is doing right now with my 05. R is gone D is gone, shifts into 3rd with a big clunk and at least moves. makes the low whine and rocks just a little in R and D but wont move. i just replaced the solenoid pack, didnt make any difference at all. maybe i`ll replace the valve body this week just to see what happens. i have 105,000 on mine though. my pan was pretty clean so i`m thinking if it was bands, would have been signs in the pan. if it was the tq, it wouldnt shift and move in 3rd. if it was the tr sensor it would start in gear. i replaced my tci shifter with the oem, replaced the filter, fluid, and spark plugs. i`m still thinking more of a electrical issue myself.

the strange part is mine did this one day, right after replacing my spark plugs with pulstar million volt plugs. then after playing with the shift cable, poking around and re setting the computer it started working fine again and ran great for about a week or so then did the same thing again. this time its been down for the last month or so and i`m thinking i`m just gonna have to buy a rebuilt trans if i ever want to drive my car again. but hate to buy a trans and it be the pcm or something. i think most of the repair shops are just just taking wild shots in the dark most often.

looking around this last month, i`m seeing alot of trans problems with the 5r55s. too many junk plastic parts in these cars