Ok so I just got my son a 2002 Concorde yesterday. The guy I got it from (owned since new) said when the transmission gets hot(?) It goes into limp mode. He said it did it twice and he parked it. I test drove it for 20 minutes on the highway and it drove perfectly. Worse case scenario I just change the transmission, however the only 3.5 transmission I can find is 500.00 and came from a 200,000 mile car. I can find lots of 2.7 ones for around 150.00 with half the milea can I just put that one in instead?
Joe, welcome to the forums - yes, you can use a 2.7 transmission with a 3.5, just change the rear transfer gears to the ones from your son's trans.
However, I'd suggest you likely have a different problem - perhaps needing a solenoid pack and valve body.
Here's a quick thread to point you towards which discusses it, but there are many on this forum.