hello, i recently had my 98 JGC transmission and trans axles for a routine service with 85k on the odometer. right after, i began noticing sometimes at highway speeds, without applying any further pressure to the gas pedal, the tranny would rev up a little bit, especially uphill. it does not seem to happen with the overdrive off though. i had noticed after inspectring the oil it does have tiny air bubbles on the dipstick. now im wondering what it could be thats causing this before i pursue this matter. the mechanic who did the job was fully aware that jeep can only use mopar oils for the jeep trannies. i would appreciate your comments. thank you

First thing would be to check have the right amount of transmission fluid.

Also, if it hasn't been done already, consider dropping the pan and installing a new filter and fluid. It's an easy job (but sometimes messy) if you know what you're doing with a wrench (for the pan) and torx wrenches (for the filter). The pan holds about 5 qts.