New Tranny or Fixable?

[Broosedamoose]

New info. I was on the freeway yesterday and I set the Cruise Control at 75 mph. The rest of the way home it ran fine. So today I had to go run an errand and when I was on the freeway it did what it's been doing and I thought about the Cruise Control. I set it at 75 mph again and it didn't act up the rest of the way. On the way back I waited and shortly after reaching driving speed it acted up. I set the Cruise Control and it was fine the rest of the way home! I'm thinking this is operator induced. Maybe just the slightest increase in throttle position causes the tranny to want to shift out of OD. So maybe the TCC solenoid is just weak. It doesn't actually shift though. It's much different than when I turn off the OD. It never did it before so it has to be something in the transmission. Looks like, Tranny Shop, here I come.

 

[cbxer55]

What you're describing sounds like the convertor unlocking and locking back up. Before you get too involved talk to the installer to make sure he cleared the PCM memory, if not you can do that by disconnecting the battery for a few minutes. You'll then need to do a drive cycle for the PCM to relearn. Before even doing that, check the fluid level, it's the cheapest and easiest thing to do.

That's funny. My 2007 Mustang doesn't even have a transmission dip stick. Can't check the fluid level at all.

btw: My mustang did the same as the OPs. Drove it to work one day. When I came out to go home, it wouldn't move when put in gear. My friend Rick, who owns Ace Transmission in Midwest City OK, rebuilt it for me with a brand new torque converter and shift kit, for $2000. I had been having issues with a P0741 code prior to it failing. Code is for Torque Converter Clutch Locked Off.

The torque converter clutch in all three of my Fords, locks up around 40 mph,. no matter which gear it's in. That's a Ranger with 4R44, Mustang with 5R55, and Lightning with a 4R100.

 

[19Walt93]

That's funny. My 2007 Mustang doesn't even have a transmission dip stick. Can't check the fluid level at all.

btw: My mustang did the same as the OPs. Drove it to work one day. When I came out to go home, it wouldn't move when put in gear. My friend Rick, who owns Ace Transmission in Midwest City OK, rebuilt it for me with a brand new torque converter and shift kit, for $2000. I had been having issues with a P0741 code prior to it failing. Code is for Torque Converter Clutch Locked Off.

The torque converter clutch in all three of my Fords, locks up around 40 mph,. no matter which gear it's in. That's a Ranger with 4R44, Mustang with 5R55, and Lightning with a 4R100.

You can check the fluid, raise it on a lift, remove the plug from the pan, and install the fill tool. With the engine and transmission warm fluid should trickle slowly out of the hole, if it doesn't, it's low. The fill through the pan b/s appeared with the 2002 T Bird, thank Jaguar for that genius idea. On the plus side, it scared Jiffy Lube away.

 

[cbxer55]

I know how it's done. It's just a YUGE PITA is all. I had to have the trans rebuilt last year due to a bad torque converter clutch. So I know it's full and it doesn't leak.

 

[19Walt93]

It's cheaper to check it than it is too run it low. Remember Trust but verify?

 

[Broosedamoose]

So tranny shop checked everything out and couldn't find anything wrong. One thing he did point out was that while on side roads the tranny is very touchy. Just the slightest increase in TP causes it to down shift. He said I would need to bring it to a tuner to have the values modified in the PCM code. What's strange is, I didn't change the PCM! It's the transmission that's different! He said if it seems to get worse or annoying I could try changing out the TCC solenoid but he doesn't think it's the issue. Gotta love mystery issues!