While freeway driving seems transmission is trying to shift to another gear but can't get there, the rpm will decrease then will shift and all goes back to speed. Happens on slight inclines on freeways. Hard to explain but anyone know have an idea what is going on? I drive a 2013 JKU

 

Yes it is probably the load sensing telling the system you are not making the rise up the hill in a higher gear so stay in the next one down. Also with your bigger than factory tires the mass is heavier so the engine has to work harder to turn them. If you had a turbo there then it would screamup the hills in the taller gear - my V8 goes up lots of steep hills in 8th gear whereas my son's 2016 Pentastar has to shift down to 4th from 6th.
Remember all changes in life are a compromise and this is no different.

 

thanks for your reply.

 

Curious what gearing and tire size you have. Welcome to JKF by the way

 

I have a 3.73 gear ratio on 35s. This slip has occurred recently at around 60,000. Not habitual and doesn't seem to occur with town driving. Thanks for the welcome looks like an informative bunch.