Just returned from a 500 mile trip through snow and ice. At cruise speed (55-70) the engine keeps raising and lowering RPM @ 2K. Also feels like it's shifting to lower gear or out of overdrive.
When I disengage the overdrive, it does the same thing.
Is this a transmission issue?
Most probably the torque converter which releases and applies again. Did you check for any fault code set?
Most probably the TPS which is getting bad, but could eventually be a speed sensor as well. But the last one normally gives problems like harsh shifts.
JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.