Overdrive on/off button?? Do any of the tacomas have this feature

Are you guys positive?

Why do our trucks shift through 5 gears and then RPM's drop again like it is using the overdrive? Is it just torque converter lock-up?

Also, While cruising at around 60 mph, and you start up a hill, the tranny will act like it downshifts out of overdrive into 5th, and then if you manually shift to 4th, rpm's will increase again when it shifts into 4th...

I searched, and couldn't find a definite answer...

EDIT - after re reading your post, I guess I'm feeling/seeing the torque converter lock and unlock...

 

And just to add a little bit more...

If you plan to keep your truck a long time and drive a lot in the 40-50 mph range on back roads, do yourself a favor and keep it in 4. You'll save that 5th gear over the long haul. My parents owned an '85 Camry and that overdrive gear (can't remember if it was a 4th or 5th gear back then) wore out somewhere around 180K or 200K miles. Too much shifting over that many miles into and out of that gear. Eventually sold the Camry LE with 238K miles on it for $5K (having spent $16K when it was new). So that was a deal!

 

+1

 

I know exactly what you are talking about I get the same thing. I should plug in the scanner at work and watch a live data stream to see it for myself. . .not that I don't believe everyone about it being the torque converter.

I drove many miles (sometimes 50+ at a time) into a strong headwind across South Dakota and Wyoming with the truck in this in-between 4th and 5th gear state (no trailer). I'm surprised the truck would let itself run with it unlocked for so long, heat?

 

When I first got the truck I thought ECT mode button was the same thing as overdrive, but Toyota worded it differently. Imagine my surprise when I find out there is no overdrive.

About finding gears.. My Taco tends to do that a bit anyways. Not as bad as it used to be though.

 

Then you're really going to be surprised to find that you do in fact have not just one, but 2 overdrives. Gears 1-4 are basically just like any old school transmission. Your 4th gear is a 1:1 ratio. Both 5th and 6th gears in your truck are overdrive.

Your transmission ratios are:

1st gear 3.60:1
2nd gear 2.09:1
3rd gear 1.49:1
4th gear 1:1
Reverse 3.73:1

Anything less than 1:1 is overdrive

5th gear 0.69:1
6th gear 0.58:1

 

I read the first page of this thread and then my brain just bled out.

I'm dying...

I would sell the Taco and get something with a CVT. That way you don't have to worry about keeping it out of overdrive.

 

It should also be explained for those that don’t totally understand the ratio process

numerically higher:1 ratio is engine speed vs out put speed

First gear being 3.6:1 means the engine is turning 3.6 revolutions for every one turn of the trans output (driveshaft As well)
1:1 they are turning equal speed (4th gear in most transmissions)

.72:1 the engine is actually slower than the output thus the drivetrain is “over driven”

Some transmissions have double overdrive

many of the more modern multi speed transmissions break the lower gear shift points up to make a smoother transition from gear to gear, this also includes possible multiple over drives

 

The higher over drive speeds allow for a lower gear in the axle and still maintain highway drivability and mileage while having bottom end pulling power for towing

older cars/trucks with 3speed non OD transmissions had higher rear axle gears for better highway traveling

I parted out a GMC 4x4 many years ago with a snow plow on it. Had 3.08:1 axle gears. Imagine how much of a dog that was to plow snow with ? But I bet it got pretty decent mileage on the highway for a 4x4 box