I'm an idiot about automatic transmissions :D

I'm an idiot about automatic transmissions
Right, so, with that established:
I have a 2013 DC V6 Auto SR5.
Which has a 5 speed auto, right? With some sort of overdrive?
Or, 5th is the overdrive?
At any rate, I can feel it shift, 1, 2, 3, 4, 5; and then there's a big rpm decrease a bit after it shifts into 5.
As if that were an additional overdrive...or, maybe that's the torque converter?

Where I'm going with this is, is there a way to make that last big decrease in rpm "switchable?"
Because it would be nice to be able to turn that off going up hill and such sometimes, whereas trying to modulate that via gas pedal/throttle position can leave it hunting around, or, shifting down to 4 when it kinda doesn't need to.

Yeah: I have no idea how automatic transmissions work.
I can rebuild a manual 4 speed though. I do understand some things!

 

5 -is- overdrive [which is it always trying to find when in D and depending
on speed and engine load]

no you cannot change how it shifts,

not without binary code installed via techstream
or manually shifting to 4 or 3 on hills

your 2013 qualifies for updated code which will make it drop out of
overdrive earlier on hills to help prevent excessive ping. there is a tsb on this.
but you need to complain to dealer yeah it pings on accel and up hills... and be
within the emissions warranty (80,000 miles or less) as this is considered
an emissions update


https://www.tacomaworld.com/threads/t-sb-0044-14-feedback-engine-ecm-reprogram-pinging.337705


Introduction
Some 2012 – 2014 model year Tacoma vehicles equipped with 1GR-FE engines may exhibit spark knock (detonation) during light acceleration and/or uphill in hot weather (80 ◦ F or higher).

The Engine Control module/ECM (SAE term: Powertrain Control Module/PCM) logic has been modified to reduce the possibility of this condition occurring.

Follow the Repair Procedure in this bulletin to improve this condition.

This warranty is in effect for 96 months or 80,000 miles, whichever occurs first, from the vehicle’s in-service date.


mine used to fart up a hill near my house, then after the update (which works as advertised) my shift points for D changed [along with whatever else they did]

 

It's the torque converter and cannot be made switchable. As you accelerate through the gears, it's 'unlocked'. When you reach 5th, it remains unlocked for a bit depending on engine load, and then 'locks'. The lock is the RPM decrease you're feeling. Supposed to help with MPG's.

If you're going up grades and get annoyed by the gear hunting, drop it into 4. I drive in 4 always unless over 60 mph. Truck has no guts in 5th.

 

thank you very much!

 

Yeah, it's not a V8; but, I'd be happy without the torque converter drop in 5th, most of the time...

 

see if you can get the tsb done, it only takes 20 minutes

 

I downloaded it; I'll try for that, thanks!

 

5 is OD. 4 is or is closest to 1:1 ratio.

 

The highlighted ratios are where "overdrive" is achieved because you are at less than 1.0.