On any type of road (flat, incline, decline) when I hit 45 mph, the transmission seems to hesitate about which gear to pick. You can hear a rumbling sound (not loud) when this is occurring. Furthermore, I notice that the RPMs fluctuate up and down by about 200-300. I have brought the vehicle to several mechanics. One mechanic suggests that it’s the u-joint since it has a small flat spot. Another mechanic thinks a software upgrade is needed. The trans was recently flushed and the issue still persists. I tried looking up any service bulletins and did come across SB 06-062, which addresses a 4th gear issue on 2006 Ridgelines, but not sure if the issue I’m dealing with has anything to do with software, plus, I did not want to pay to see the details of 06-062.
Any advice would be greatly appreciated.