A few times when I have braked to a hard stop there is a delayed, hard THUNK in the drive train. The first time this happed I looked in the rear view mirror to see if someone had rear-ended me. Yesterday on the way to work I had to brake hard to avoid running a stop light and the same thing occurred. While accelerating after the light turned the truck was slow as if it was in a low gear, but the rpms weren't climbing much. Further down the road there was a rough shift and things returned to normal. The sluggish acceleration and abnormal shift occurred again on the same trip after a normal stop (no thunk). Everything seemed normal on the trip home after work.

Has anyone else experienced these symptoms? If there is a problem with the transmission I would like to get it repaired while it is still on warranty. My 06 doublecab has around 63K miles on it. The transmission fluid was flushed at 55k.


Thanks!

I would do the following:

1. Treat the ATF with Auto-Rx (Auto-Rx for transmissions (http://www.auto-rx.com/transmissions.shtml#automatic))
2. Check torque on the four rear transmission mount bolts
3. Check operation of e-brake bellcranks
4. Lube driveshaft (if 4WD)
5. Drain/fill rear differential
6. Check torque on rear leaf spring u-bolt mounting nuts (98 ft/lbs)

#4 for sure.

^ i'm with this guy.

I have an 05 AC which had transmission problems due to two corroded pins in the 15 pin connector that is connected to the wires coming out of the transmission. We have snow and salt here in New England. It seems that the connector does not have dielectric grease packed in the connector from the factory.

Along with all of the above I would unplug the connector and take a good look at the pins then pack it with grease if it is Ok when you put it back together. If there are any pins corroded or broken off, looks like a dealer job.

Do a search for lubing the drive shaft. It involves a lot of grease with 8 spots (with 4x4) and lots of grease in the last one (back). There are a lot of posts about feeling a bump when stopped and this stops it.

I live in NE Ohio with an '05 also with corrosion on electrical pins at connector to transmission. 3 corroded for sure and 1 broken off. Crappy type connector with no dielectric grease for protection. It's in an AAMCO shop today (11/13/2012) being repaired, approx. $400.00. Replacement connector hooked to transmission costs about $80.00 with the rest for labor/supplies. I suggested replacing the cable connector (female plug part) also but service guy said entire electrical harness would need replaced and was about $1000.00! He feels confident he can clean and reuse old one...we'll see.

How did you find out it was the pins? I brought it to the dealer and they wanted to replace the transmission for 3K. I was not happy and took it to the local transmission shop where they found the problem. I also found it on the internet. It cost me the $400.00 also. I wrote and called Toyota with no response from them. I asked for my money back from the dealer for finding the wrong problem and wanting to charge me for a new transmission. They refused.

How did you find out it was the pins? I brought it to the dealer and they wanted to replace the transmission for 3K. I was not happy and took it to the local transmission shop where they found the problem. I also found it on the internet. It cost me the $400.00 also. I wrote and called Toyota with no response from them. I asked for my money back from the dealer for finding the wrong problem and wanting to charge me for a new transmission. They refused.

thats why i dont like dealerships!

This sounds very similar to what my tranny was doing. Any time I slammed on the brakes it would slam back into gear after a few second pause. It felt like I was being hit from behind. If I tried to accelerate while it was doing that it would rev up and slam back into gear, like a neutral drop. Chirped the tires, big clunk, not good. My truck is an '06 as well.

I also had a couple times where there was no power afterwards, it seemed to me like it was stuck in 3rd gear and wouldn't downshift. The engine did its best to load up the torque converter but of course the RPMs wouldn't get very high and acceleration was slow. The engine was also working like hell to overcome the high gearing. Turning the truck off/on made it go away.

The short of it was the tranny was slightly low on fluid, so as the fluid sloshed to the front of the pan, the pickup would gulp in some air. Of course that caused a brief drop in hydraulic pressure so the clutches etc released, immediately engaging again when the pressure was back on, causing the clunk.

The long story is I had it checked out by a mechanics instructor at my work (I work at a college with automotive programs). It was holding a pending error code, DTC 2714, regading one of the shift solenoids. I bought the parts and had them replaced, free labour.

The problem was worse after that, it was happening with any quick stops (not just panic stops like before) but also did it in tight turns and when gunning it in reverse (backing up a steep driveway). I took the truck to a reputable Trans mechanic and he quickly spotted the low fluid. He added 2.5 litres and it's been fine ever since, about 6 months now. Only charged me 1 hour labour as I provided the fluid (the fluid that should have gone in when the solenoid was replaced). He could have ripped me off but lucky for me he's a good guy.

I thought the fluid might be low from the start, and let the automotive guys check that for me. They thought it was OK but they were wrong. When they opened the check plug on the trans a little fluid came out like it's supposed to. But I think the tube (see picture) filled with fluid as the truck drove around, so all that came out was the contents of the tube. They mistook that to mean the level was set properly.

91823

Worth checking out.

-Kent