40mph Tacoma Shake

Pretty sure it's the transmission, that's usually where it goes to the next gear and it's the hardest to shift into. Same goes with my 9th gen corolla. When you get around 40 you have to kind of manually make it shift into the next gear, just give it a little more gas and as it enters the next gear it should go away. In my car I don't shake as much as hear kind of a humming sound, the closer I get the more noticeable it is. Once I hit the next gear it goes away. This will be worse when it's cold. Toyota transmissions are designed to act a little limp while your engine warms to protect the transmission. After getting my transmission fluid flushed it was a bit less noticeable, but still there. The transmission is healthy and the fluid wasn't dirty and still isn't; just a yota thing. Side note, your entrance into the next gear shouldn't be super noticeable. If it's not a smooth transition you might be having an issue.

 

@b-walla Welcome to The Forum!

 

Sounds alot like torque converter shudder. Its hard to tell without a scan tool but a dealer should be able to use a factory scan tool to monitor Torque converter slip speed. There should be a specification they can compare it to. Hope this helps!

 

Got an update, folks.
Talked to a dealer service jerks today. They said we can do this. They have a way to disconnect torque converter - they have a tool which you connect to truck's computer and by sending a certain code you can have it disconnected electronically. Not sure if it's 100% true but at least something than nothing. So what we are going to do: have it connected, get it on the road driving around 40-45mph at 1000PRM and 5th gear (conditions that apply to my situation) then catch the moment when it's shuddering and disconnect the torque converter via that tool. If the shudder goes away - it's a torque converter problem. If it's not, I guess then it would be something related to a driveline along with carrier bearing, u-joints, etc., or it it's a transmission itself. However, I'm gonna be busy whole next week and do it on the following week. So once it's done - I'll update ya.

 

ever hear back? I am about to be replacing my CB

 

Hey guys, sorry for the delay - been busy as hell. Anyway, went to a dealer two days ago to do the procedure I described above. Me and a Toyota tech were driving around for about 20-30 min, prior we connected a device which looked like 20 y.o. laptop to a truck comp port, then I hit the road and tried to maintain all the driving parameters I mentioned before which allow reproducing the issue: 40-45mph, 1000RPM and 5th gear. So at the moment it starts shuddering, I'd tell him and he would disconnect torque converter programmaticaly via the device. Technology, huh! When he was saying it's off, it would drive much smoother with little more RPMs added, he explained the slight RPM boost that torque converter is disconnected and the additional power from engine was being flowing thru the transmission directly. So we did a series of those manipulations and it felt like when torque converter is disconnected, it's driving much better with no shudder. So I guess my next step is to replace it. The damage is nearly $2500 which is quite a bunch of money so my wallet is gonna hurt... Well I guess I will take a look if someone else around can do it cheaper. Will letcha know. Thanks.

 

Glad to hear it worked!

 

Folks, got the freaking torque converter replaced, guess what - that didn't help much. Switches the gears smoother but I'm still feeling damn vibration when driving on 5th gear around 40mph at 1000RPMs. Something gotta be resonating at those frequencies I believe... Gotta sell damn truck to get rid of it - that's the only thought that I'm having right now...

 

I am curious if it could be a flywheel problem
being out of balance or out of kilter. If you have eliminated
all other driveline rotating issues.

 

Thanks for your input brotha. We actually replaced all 4 wheels at dealership earlier when were troubleshooting the issue. We put brand new and drove around - the same thing, no effect.

 

One other problem would be the drive shaft needing balancing if all other problems have been looked at.

 

it's brand new though. However the issue is experienced at ~40mph 1000RPMs on 5th gear olny - any of those changes and the problem goes away. I bet if it was driveshaft then it would be constantly happening, wouldn't it?

 

Yeah, don’t understand that

 

If it only happens in one gear and any dpeed in that gear but gets worse as rpm in tranny increases. My conclusion would be a bad clutch pack for said gear. Plates could be shuttering in that gear. Have seen it in some race trannies but nit in a lower hp vehicle.