Transmission or something else?

I've got a 2006 4.0 V6 2wd Auto. 180k mi

It recently (within the last couple weeks) started doing this weird thing where I feel a weird bump from behind when I come to a stop. Then, when I press the gas, it takes a second to go, and just jerks into gear. The bump at a stop is almost every single time and the jerk to drive is pretty frequent as well, although a bit less. Sometimes it will take a full second or few before it just randomly throws itself into drive.
I'm not gunning it, I'm not stopping and immediately gassing it. I thought maybe the fluid was just low or something so I planned on flushing and changing it since it was due, but then the other day I was at a red light at an intersection and it just slipped out of gear. It didn't go back in, when I let off the brake I just rolled backwards. I turned off the truck and restarted it and it was fine. A week or 2 ago I had to make a long drive to the airport and I noticed it wasn't shifting into the highest gear at highway speeds, it would stay in a lower gear and just rev really high rpms. in DRIVE. While I was watching this happen the check engine light came on and I felt a weird loss of power or something and I immediately let off the gas and pulled off to the side. Restarted the truck and it was fine. It did that high rev thing again the other day while driving to work but it went away very quickly. Took it to dealership and they want $3000 to replace transmission. They flushed fluid and said it was still doing the gear slips and bumps. Dealership said the fluid had a little bit of debris in it but not a lot. I am picking it up today or tomorrow. I read about other people having the bump issue but not these other weird symptoms.

TL;DR:
Truck bumps at a stop (feels like it's going out of gear), jerks into gear at a go.
Once, truck has gone out of gear at a stop, didn't go back in until restarting truck.
Twice, truck has refused to shift from lower gear at highway speeds. One time check engine light came on during, restarted truck and no light, truck worked fine.
All of this happened within a 1 month period. Weird bumping started, then in last 2 weeks, all other weirdness happened.

 

Check your U-Joints.

 

Your experiencing axle wrap. Change u joints. And carrier bearing. Also it would be a bad idea to replace those crap stock leaf springs. With some wheelers offroad springs or similar.

 

Sounds like a failing auto. At least the slipping part. Bring it to a trans shop for 2nd opinion.

 

I read about the U-joint problem but I didn't hear about it causing all this other stuff. Good lord. Also, the leaf springs were just replaced a couple months ago by the stealership under a Toyota TSB.

 

This could be part of it. But falling out of gear and slipping is not axle wrap IMO.

 

When you say "out of gear" at a stop, do you mean you're putting the transmission in neutral?

Did the dealer flash the ECU? If not, I believe you can accomplish the same thing by disconnecting the battery for a few minutes.

 

Sounds to me like the transmission is on it's way out...

 

Yeah i had mine done to but the wrap was still present afterwards. Also it' a good idea to do a drain and fill on your trans. I wouldn' recommend a full flush with the symptoms you have. Clean your trans pan magnets as well

 

If it turns out to be a bad trans I would look at the local salvage yard for a replacement and a good non dealer shop to install it. Would easily cut that dealer estimate in half. Should be plenty of good used ones laying around with low miles due to accidents and the long production span of the 2nd gen.

 

True I didn't read that part

 

The transmission itself is just slipping out of gear. The gear stick is not going into neutral.

 

Oh, that's no bueno. If the dealer said your fluid checked out, I guess I'd try to flash the ECU. If that doesn't work, it might be on its way out the door as others have said.

 

It might be worth the $100 to let an independent transmission shop take a look at it. Though I agree it is probably time to start shopping for a good used, low mileage trans.

 

Thanks, I am going to try that after I pick it up today. If it isn't that, I will be taking it to a local shop that is pretty reputable.

 

Thanks for all the replies guys

 

Good luck!

 

did you do an oil change recently? I think they might have drained the tranny

 

Now why do you have to go and open that can of worms? This does not seem to be the case in this instance there inspector...

 

I do the oil changes myself. I didn't drain the tranny. Man that'd be bad lmao.