A Tidbit of info concerning the Automatic Transmission shifting issues

Keep in mind this is second hand information but I was talking to a family member of mine last night who works at a Dealership (and has for over 20 years). Apparently one of the Master Techs was having issues with what he thought was an ECU on a 3rd Generation Tacoma with the truck having shifting issues as one of the symptoms. Apparently there is a sensor that he figured out how to bypass (an Atkinson sensor?) and when he did the truck shifted beautifully afterwards. I'm not a tech by any stretch, just thought I should relay the information.

 

Just think of the money you could make if you could get him to show you what he did.

 

sensor. hmmm. wouldn't it throw codes

 

I don't know if ppl realize this but the 2nd gen transmissions shift just like the 3rd gen. The only difference is that the 2nd gen has more torque lower in the power curve. This lets the motor pull in over drive even at low rpms. The 3rd gen motor doesn't have the torque at low rpms to do this so the transmission unlocks the torque converter or downshifts. Either way, Toyota transmissions seem to want to get to high gear as fast as possible. The fact that the new trans is geared a little higher and the motor has less low end torque leads to a different feel than the 2nd gen. In reality my guess is they both follow similar parameters but the user experience is different.

They also downshift as soon as you touch the brakes going down a hill and then refuse to up shift. It's really annoying.

 

I agree with everyone who doesn't like the whole transmission shifting issue. But these trucks do have the power they need to get up and go when needed. That may sound like a blender on frappe but if you're going down the freeway at 55 and need to get around someone, you slam the pedal to the floor, the Tanny jumps does into 3rd, the engine again sounds like it's making a smoothie but it will get you. Up to 80 just fine. It's nothing like my BMW, not even a tiny bit close but it does do its job. I'm guessing with more drive time most people will just get used to it. We shouldn't have to, but it just a reality with these vehicles. I'll add the ShiftSense helps a lot with this. It's not perfect but for the $175, it will ease your pain with the shifting. It was totally worth it for me.

 

Personally I think it has something to do with the fact that there is 1 more gear in the mix, combined with an engine that can operate in Atkinson Mode (narrower or more peaky torque/power curve,more fuel efficient engine state, apparently) or in Otto Mode (wider power/torque curve, when the engine requires power). So you need power, the engine down shifts and drops into otto mode and accelerates away. Then you eventually get up to a cruising speed (steady state operation). Does the engine upshift, or drop into atkinson mode, or? Does it to this simultaneously? What if you're on a slight incline and need some power. Does it downshift, how much? When does it drop into otto mode?? What if you need to accelerate a little bit?

 

Here you go, problem solved:

https://www.tacomaworld.com/threads...troller-now-available-for-gen3-tacoma.490113/

 

http://www.dz-custom-innovations.com/

 

Yea. The double overdrive definitely contributes. As well as the the torque being at higher rpms.

 

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This is why I love my 4.0L and 6spd manual. Roll on the throttle in 6th, pass, carry on.

 

I will probably get flamed for this but everyone's entitled to my opinion.

I agree that the 3.5 is a totally different engine than the 4.0. All manufactures are doing everything they can to increase mileage. Smaller engines with torque curves at higher RPMs is a very common solution. I don't think we'll ever see a low RPM torque curve anymore because that would require a larger displacement which would typically mean worse MPG. I don't have a 3rd generation yet and so I don't have first hand knowledge on the transmission shifting frustration. I do know that other manufactures are dealing with the same problem. Their solution is provide transmissions with many more gears. I do have some experience with the Ram and Ford trucks and they have 8-10 speed transmissions. They are constantly changing gears because they have so many options to get the best performance and economy. I just think that 1 more gear in the 3.5 from the 4.0 isn't enough. If there were say 8 gears as an option then maybe there wouldn't be so much hunting around for the perfect combination. I would like to see Toyota get with the times and give us 8 or more speed transmissions. Yes, it will cost more in dollars and weight but other manufactures do it and are successful. We are stuck with high revving power curves so give us a transmission that can take advantage of it. You all know that as soon as they invent a CVT transmission that can handle the rougher duty of a truck, you'll only get that option in an A/T. I hate CVTs but that's that way the world is going. 1 more gear in a 3.5 over the 4.0 transmission just doesn't cut it IMO.

 

I drove a car with a CVT for seven years and loved it. I've only got 1,700 miles on my new Taco so I'm still adjusting to the tranny but I have no complaints. CVT's are as smooth as a babies behind though.