2012 Tundra crewcab TRD, SR5 4x4 Trans question

I've owned my 2012 Tundra since 2015 and have had it serviced for many years at a local Toyota dealer, now with 116,500 miles I've notice it struggling in tow mode. The RPM's are much higher at the 55-60mph. Is this a potential problem with the transmission going bad????

 

Are you comparing it to when it’s not in tow mode or what your remember the RPM being in Tow mode from a year ago?

Tow mode changes the shift points to keep RPM higher for towing ect.

Excessive towing over the years can really strain a transmission. If the RPMs are drastically higher than what you think they should be it could be starting to slip.

How does the truck drive in normal mode with no tow load or weight in it?

 

Hi Jeff_5_7 thanks for your response. To answer your first question when I first started rv camping I established different speeds while towing our trailer for best miles per gallon (55mph-60mph) with that my RPM was consistent at 1600rpm - 1800rpm. This last trip 1500miles round trip rpm was approx. 2100 - 2600rpm temperature a bit higher but not enough to be alarmed. second question about normal drive mode is un-noticeable.
A little ditty about me... I'm not a mechanic and know nothing about vehicles except to change fluids often prior to specifications. I'm very alert to my instruments' gauges with towing the RV trailer. Oh and bye the way I'm a worrier.
Thanks in advance!