Tranny drops out of drive coming off highway speeds

[dat5574]

Hi,

I have 2001 4runner with automatic transmission with 150K. For some history, in 10/2012 I had the shift solenoids replaced along with all the tranny fluid at 138K miles.

Now, I drive the same route every day but 3 times in the last month during my commute, while exiting off the highway to a stop light (twice) and coming to a stop on the highway due to traffic backing up (once), the truck drops out of drive. I then had to coast off to the side, drop in in Park, then shift back into Drive and proceed on my way.

This does not occur while driving around town at lower speeds during stop-and-go traffic.

Mechanic #1) The same guys who replaced the solenoids and fluid now say based on the description and the burnt tranny fluid, the clutch plate is slipping and quoted me on a used tranny. They also suggested I don't bother doing a flush b/c it can make it worse.

Mechanic #2) Couldn't duplicate the issue (but tested it only around the block or two). Said the fluid is a little burnt but he's seen worse and doing a flush now since it's only been 12K miles since 10/2012 solenoid repair, I would be wasting my money. He also added, it could be a clutch plate but it could also be something electrical.

What now? Is there a way to diagnose this issue since it doesn't happen all the time?

 

[afg10000]

Do you have a Scanguage? Do you know if it's throwing any codes? I'd start there. If you get a p0770 that could be bad. At least it's still going into drive from park easily. That's probably good. If the torque converter was angry, it would not be happy going into 1st and 2nd gear from stop. It would be good to know what temps the tranny fluid is running at or getting up to. I'm no expert at this but I did just deal with major tranny failure and when it went, it went bad. I'd start with codes then take it to an actual transmission shop and have them test it -

 

[dat5574]

Yes, I don't have them in front of me but they were related to an exhaust leak after the cat converter/O2 sensor which is a whole other issue (Bank 1 sensor 1 I think?)

But nothing related to the transmission. I just made an appt. next week for a shop that specializes in them.

I'll keep my findings posted here for anyone else who has similar issues.

Thanks.

 

[Bryan1]

When I first bought my truck, I had the exact same issue but it worked itself out. I've had no problems for months but it's still throwing a P0773 (Shift Solenoid E). I'm not going to mess with it unless it acts up again.

 

[dat5574]

One of the codes Auto Zone read (I don't remember the code) but was suggesting "Yaw Rate Sensor" is bad. Can this be related to the shifting out of gear while decelerating from high speeds? What are the symptoms of this sensor?

 

[dat5574]

Well I took it to a transmission specialist that was recommended to me by a couple mechanics.

They checked the fluid, drove it but couldn't find anything or didn't see any codes except the one for the catalytic converter. One thing he said was in his experience is brown fluid in Toyotas is common...he wasn't sure if it was the clutch plate material they use but it's nothing to get alarmed about. (Just what he told me so who knows).

In any case, the symptom returned a day or two after I took it in.

1.) Dropped into neutral when coming to stop from high speeds (exit ramp, traffic jams)
2.) Transmission is hot
3.) Another thing I noticed is typically I'm on a an incline when this happens. But then again, most ramps are. But it happened this morning on the highway when stopped on slight upward incline as well.

 

[kball]

Sounds like sticking solenoids or valve body. Brown fluid is common because people think Toyotas are so good they never need servicing. If it's brown, it's burned and needs to be changed.

 

[dat5574]

Thanks, so if I get it flushed, I've read there are two types.

1). One machine that pumps new fluid through while removing old fluid on the other end gradually replacing the trans fluid.

2.) Second method includes dropping the pan and change the filter (which is better since you can see if there's any metal in the pan).

If they perform #2, will they be able to diagnose the solenoids or valve body at that time too?

I'm trying to figure out what type of diagnostic service to have done to identify the problem. Just test driving isn't enough right now.

In my first post, the guys who changed the solenoids 10 months ago didn't take anything apart and just suggested I need a new transmission so I'm suspect about that.

 

[the great him]

so method 1 is best if you ask me, you can drop the pan yourself at home and check for metal in the pan, i think dont quote me but you only lose like 3-4 quarts of fluid from the pan im not sure though. but dropping the pan will only get part of the fluid out, to get a full flush you need to hook it up to a machine and pumps in the new, forcing the old out. id do this sooner than later.

it also sounds like valves or a solenoid to me as well. just because he replaced them a little bit ago does not mean he replaced them with bad parts, did you see the old parts, are you sure he actually replaced them? did he use the right parts and or the right fluid when he did this? as stated above brown fluid is bad bad bad, that means burnt fluid. if you have burnt the fluid in 10months that tells me you have some serious issues with your trans. id look at installing a trans temp gauge and keeping an eye on trans fluid temps. you should not be much over 200* but with your brown color i bet your closer to 240-260 constantly. and thats not good. thats a sure way to eat up a trans in no time. you might have other issues like a blockage in the lines or something, and thats something that a power flush should be able to clear. now some dont like power flushes cause they say its just gonna brake that stuff lose and move it to some place where it will cause other damage... well your screwed one way or the other possibly, id at least feel comfort in knowing that i tired something over nothing...

 

[audiness]

I think you should do 3-4 drain+Fills , save the old fluid. See if it gets any better. don't do a flush.