There are no software flashes availabe to correct a shudder condition on an 07, 300 with a NAG-1 (Hemi)transmission. I advise that you have a dealer check for proper fluid level. Fluid level must be checked with a CHRYSLER STAR SCAN tool monitoring fluid temp and a special dipstick. This is why the filler tube is sealed with a plastic cap. NAG-1 transmissions are known to have fluid leaks at the wiring connector adaptor. Fresh ATF-4+ Fluid may sometimes help the condition. Vehicles equipped with a V-6 engine have a different transmission.
Hi this is Scarlet in Ky...I just told another guy on here that I had mine looked at today due to shifting/idoling problems. My engine light was on so I had it hooked up to the computer and it said I have EGR Valve system fault, that the voltage signal from the EGR sensor A is too high for the engine operating conditions. I looked that up on here and it did say it can cause shifting/idoling problems. Have you had any issues with wheel bearings? I also have rt front wheel bearing bad. The race is stuck, 1st time I took it off you can freely see the ball bearings in the rotor. Went to take it back off yesterday to do all my repairs, tie rod end on driver side, we couldn't get the rotor back off this time????