transmission

I bought a 2013 tundra a few years ago with 50,000 miles now has 86,000. It seems when I have it on cruze control. that anytime going up a hill if it slow down at all maybe 1mph it will down shift then accelerates pretty hard. Seems to do it more when pulling RV. I have 4.6 2wd 2013. Is this normal?????

 

I do not have a second gen, but rather a third (5.7), however I believe the engine and transmission is fairly similar. These trucks are noted to have a 6 speed tranny, with 5th and 6th being overdrive gears, intended for freeway cruising (fuel efficiency). I believe Toyota recommends putting the truck in S mode 4 for towing. Keeps truck out of overdrive gears and keeps power at hand for just this exact situation. You will get a lot chiming in about this, but essentially, yes, if your truck is in 5 or 6th gear it will likely downshift to 4th gear to improve power to get up the hill. And ensure you have tow mode one to improve gear range. Hope this helps.

 

I have a 5.7 but I have this same experience with cruise control up hill. You really want to be in manual mode climbing those hills with a trailer

 

I believe they discontinued the 4.6 for 2020. Last Model Year for the 4.6 was 2019 IIRC. Mine is the 5.7. None the less, the statement still stands for the 4.6 folks out there.

 

I noticed this characteristic, plus a lot of un-necessary shifting on the drive home from the dealer. Not an endearing feature, but yes, it's normal for mine.

Cruise control adds throttle to maintain speed. You may not even see much change in speed, but the CC is opening up the throttle plate demanding more power, until operating parameters (set by Toyota) call for a gear change. If you're only half way up a long hill, you may see a second shift, then jockeying between the two gears as you top the hill.

Welcome from the Texas HILL Country.