GEN 3 TACO TRANNY: MAYBE NOT QUITE AS BAD AS SOME THINK

My 2020 Taco's transmission is great in town. Does exactly what I think a transmission should do. But on the highway at 65-70 it will downshift easier than what I think it should. I heard there was a TSB out so I took my truck in. TSB-0092-20 as my Vin fell under the TSB's vin list. "CZ5AN"

Applicability
Year 2019 - 2020 Tacoma VDS(s): AZ5CN, BZ5DN, CZ5AN, DZ5BN, EZ5CN, FZ5DN, GZ5AN, HZ5BN, RZ5CN, SZ5AN Engine(s): 2GR Transmission(s): 6AT Introduction Some 2019 – 2020 model year Tacoma vehicles equipped with a 2GR-FKS engine and an AC60 transmission may exhibit one or more of the following conditions:
 Lack of power
 Delay/Hesitation
 Frequent shift change

When finished the Service Manger said my truck didn't fall under the TSB as it had the latest and greatest software all ready installed. I asked then why will it downshift on level to slightly elevated ground? He said what I was probably noticing was the torque converter locking and unlocking and not the transmission actually downshifting. Which I actually had thought of before. So I thought I'd test his theory and sure enough it appears in this one instance he's correct. Please see the pics below. I hear Toyota has improved the 3rd gens shifting over the years. But I'm wondering is it as really as bad in all cases as the complaints? Or in some cases is the torque converter just doing its job?

Top pic cruise set at 67 mph, In "D" then moved to Sport mode, says 6th gear.
Bottom pic cruise still at 67 mph. I let the truck do what I thought was a downshift in "D".
RPM's increased 400-500 truck says still in 6th gear.

 

Putting it in sport isn’t telling you what gear it’s in but rather restricts the upper limit.

 

Right. S6 means it may be in any gear 1-6.

 

So I may be correct. Or I may be wrong. I guess further research is warranted.

 

5th gear at 67 mph calculates to 1959rpm.

6th gear at 67 mph calculates to 1647rpm.

That was a shift not TC unlock.

 

We shall see. I'll do the same 67 mph test and limit the upper shift to S5. We'll see what the RPM's are then.
May be 1959. May be other.

 

If you have stock gears and stock tire size, it will be 1959. The math doesn’t lie.

 

Tacoma has a sport mode?

 

True.
Men lie
Women lie
But numbers don't lie.

That's why (no offence) I'm not taking your word for it. And I'll run another "reality" numbers test.

My tires/wheels are not stock size. In reality I'm running about 6% faster than 67 mph or about 71 mph.
Really don't think that matters as I'm still using the factory calibrations tach/speedo.

 

Yes! When in Sport mode and equipped with the skewp you get an extra 0.15 hp!

 

X2

 

1600 to 2000 rpm is 25%. That would be a hell of a lot of torque converter slip.

 

All i know my tach says around 1500 rpm when doing 60 mph.

 

Actually 20%. But you are correct.

 

dunlap837
Equates it to be 16%.

 

"There are three types of lies - lies, damn lies, and statistics." -Benjamin Disraeli

In this case, your speedometer is wrong because your tire size is altered, but the gearing and tach don't care. You could correct your speedometer to display 71 mph, the tachometer won't change.

Sport mode isn't really sport mode or manual shift mode - it just keeps you from exceeding that gear. Try coming to a complete stop and then starting in s6 - you aren't starting in 6th gear, and you will feel it shifting through the gears until it finally reaches 6th.

Or put another way, 2000 RPMs is a 25% increase from 1600 RPMs.

 

That's just like, your opinion man

 

Worded like that you are correct.
For an downshift shift or unlock whatever the case may be. 1600 to 2000 we have a 25% increase in RPM's
But for upshift or lockup 2000 to 1600 we have a 20% decrease in RPM's
Both are trivial.

 

That’s very low rpm. 5th gear on the 6AT is still higher than 6th on the 6MT