Guys, I asked my mechanic to flush my Rav4 V6 transmission, and the trans now malfunctions.

Shifts well but slips on 4-5. The technician says its the solenoid switches but I really do not agree. My reason - there has been a swap but the issue remains. The fluid was burnt, hence my reason for a flush. There was no issue after the flush until the filter was replaced. This problem now is an improvement from slippage on 2-3, and erratic shifting. According to him, the replaced solenoids were responsible for the improvement. If so, why does it not fully cure the trans? I have seen him rebuild transmissions but I tend to disagree with this.

I have read someone who had failed solenoids on same trans, but replacing them did not solve it, though his issues were more than mine. A rebuild, and later, reset of the trans ECM settled it.

Since the fluid was burnt, could there be some underlying problems? I don't want to throw money away buying wrong parts. Any ideas?

Thanks.

U SAY U FLUSHED OR YOU DRAINED?..........the 2 are not the same, flushing requires using pressure/pump or to pump/suck out the old fluid and then replace with clean new fluid..............this method isnt not advisable when the fluid is burnt/dirty...cos the pressure will push the particles/dirt into cracks/hard to reach places in the gearbox, and they will lodge there and cause trouble.

a drain on the other hand , is simply opening up the valve below and letting the fluid drain by gravity after which u refill with new fluid...this method takes out only about 4liters, so its recommended to do this 2 or 3 times so as to get rid of all the bad fluid


3rd point: what type of fluid did you put back in th rav4?...........hope not abro/seahorse/oando?

[sup][/sup]I don't think a pressure pump was used, but the transaxle was opened and torque converter drained

.I refilled with Toyota's WS. took almost two 4 litre tins to guage.

Go and buy another transmission. From your story you have a bad maintenance record for your transmission. For you to have a burnt smell from the oil you must have had the fibre burnt and sludges too. Those sludges still had the fibres grip well but as soon as the oil was drain the sludges couldn't hold on to the fibre. You can as well run a scan. But be prepared to buy another transmission. If I were your mechanic immediately I check the nature of your transmission oil would have told you same thing am saying. Am very sure you have never serviced that transmission right from whenever you bought the ride

mayor2013:
Go and buy another transmission. From your story you have a bad maintenance record for your transmission. For you to have a burnt smell from the oil you must have had the fibre burnt and sludges too. Those sludges still had the fibres grip well but as soon as the oil was drain the sludges couldn't hold on to the fibre. You can as well run a scan. But be prepared to buy another transmission. If I were your mechanic immediately I check the nature of your transmission oil would have told you same thing am saying. Am very sure you have never serviced that transmission right from whenever you bought the ride

Hmmmmm.so u still exist?jim jones

Kashif:
Guys, I asked my mechanic to flush my Rav4 V6 transmission, and the trans now malfunctions.

Shifts well but slips on 4-5. The technician says its the solenoid switches but I really do not agree. My reason - there has been a swap but the issue remains. The fluid was burnt, hence my reason for a flush. There was no issue after the flush until the filter was replaced. This problem now is an improvement from slippage on 2-3, and erratic shifting. According to him, the replaced solenoids were responsible for the improvement. If so, why does it not fully cure the trans? I have seen him rebuild transmissions but I tend to disagree with this.

I have read someone who had failed solenoids on same trans, but replacing them did not solve it, though his issues were more than mine. A rebuild, and later, reset of the trans ECM settled it.

Since the fluid was burnt, could there be some underlying problems? I don't want to throw money away buying wrong parts. Any ideas?

Thanks.

B4 u change d transmission fliud,did u notice any changes in d performance of d gear box?

mayor2013:
Go and buy another transmission. From your story you have a bad maintenance record for your transmission. For you to have a burnt smell from the oil you must have had the fibre burnt and sludges too. Those sludges still had the fibres grip well but as soon as the oil was drain the sludges couldn't hold on to the fibre. You can as well run a scan. But be prepared to buy another transmission. If I were your mechanic immediately I check the nature of your transmission oil would have told you same thing am saying. Am very sure you have never serviced that transmission right from whenever you bought the ride

I don't know how you rushed into this conclusion, with the info I provided. Well, the car is just five months with me, and I know when to change transmission oil. I noticed the burnt fluid when I checked it in the morning before driving back from the east. I understand the fibre has already been changed, and there was no sludge. The repair tech said the only problem are the linear solenoids.

disloman:
B4 u change d transmission fliud,did u notice any changes in d performance of d gear box?

There was absolutely no performance issue with transmission before the fluid change.

Kashif, you still have not said what type of fluid you used.

When clutches start slipping, best bet is to replace transmission. Its a nigerian thing, rebuilding has no guarantees.

Meanwhile I ask again, what fluid did you use? Visco 2000?

GAZZUZZ:
Kashif, you still have not said what type of fluid you used.

When clutches start slipping, best bet is to replace transmission. Its a nigerian thing, rebuilding has no guarantees.

Meanwhile I ask again, what fluid did you use? Visco 2000?

visco 3000, Abro is not left out

Mr kashif. The truth be told go and get another transmission. Drop the marine stories told by your mechanic he is only digging more hole into your pocket

GAZZUZZ:
Kashif, you still have not said what type of fluid you used.

When clutches start slipping, best bet is to replace transmission. Its a nigerian thing, rebuilding has no guarantees.

Meanwhile I ask again, what fluid did you use? Visco 2000?

Are you serious? It was filled with Toyota WS ATF. That is the recommended fluid by Toyota.

Unless you buy a new transmission, there is no guarantee either. Nobody sells a working transmission if the car is not accidented. I tested the solenoids with him, and saw that the four linears are out of resistance range. I had doubts, but when I learnt he has changed the fibre, some confidence was restored. I would rather go for a rebuild if the dude knows his onions, unless I have the money for a brand new transmission.

mayor13:


Mr kashif. The truth be told go and get another transmission. Drop the marine stories told by your mechanic he is only digging more hole into your pocket

Can you give me one reason I should buy a transmission? A transmission slipping at 4-5 should be replaced when a component as simple as clutch solenoid or pressure solenoid could be the culprit? You seem to have a knack for leaping before looking. If I need to buy a transmission, the advise would not come from you. Thank you.

Kashif:

Since the fluid was burnt, could there be some underlying problems? I don't want to throw money away buying wrong parts. Any ideas?

Thanks.

Burnt fibres and as a result, clogged fluid channels and solenoid ports.

DECOtech:


Burnt fibres and as a result, clogged fluid channels and solenoid ports.

I think so, only that the transmission was working perfectly before the fluid change. Expecting replacement solenoids on Monday.....

The reliability of Toyota and cost of ownership will bankrupt some owners in Nigeria.

Sometimes when a part needs replacement mechanics give hope of repair that only benefit the mechanic by suggesting all forms of modification

sultaan:
The reliability of Toyota and cost of ownership will bankrupt some owners in Nigeria.

Sometimes when a part needs replacement mechanics give hope of repair that only benefit the mechanic by suggesting all forms of modification

Toyota is unreliable? Kidding me? You have some facts?

I still don't know why fellas think a transmission cannot be repaired. They always shout, 'replace it!, buy another!'. If there is no water or chemical contamination, transmissions could be repaired. This technician works on transmissions only, and has rebuilt units from scratch. He knows when to recommend a replacement. He has said, ' don't pay if it does not work', and I am willing to play...

Kashif:


Toyota is unreliable? Kidding me? You have some facts?

I still don't know why fellas think a transmission cannot be repaired. They always shout, 'replace it!, buy another!'. If there is no water or chemical contamination, transmissions could be repaired. This technician works on transmissions only, and has rebuilt units from scratch. He knows when to recommend a replacement. He has said, ' don't pay if it does not work', and I am willing to play...

I am very interested in the outcome of your project, and if it works, please share the contact of the guy you are working with.

One word of advice, don't ever use RTV silicone adhesive to seal your transmission use anaerobic adhesive or sealant. The former is what local techs like to use but you risk it breaking away and clogging oil channels and consequent transmission failure.

Let me (us) know how it goes, I have been following silently but felt I should put in this word

IdaraCHODB:


I am very interested in the outcome of your project, and if it works, please share the contact of the guy you are working with.

One word of advice, don't ever use RTV silicone adhesive to seal your transmission use anaerobic adhesive or sealant. The former is what local techs like to use but you risk it breaking away and clogging oil channels and consequent transmission failure.

Let me (us) know how it goes, I have been following silently but felt I should put in this word

Beautiful.

IdaraCHODB:


I am very interested in the outcome of your project, and if it works, please share the contact of the guy you are working with.

One word of advice, don't ever use RTV silicone adhesive to seal your transmission use anaerobic adhesive or sealant. The former is what local techs like to use but you risk it breaking away and clogging oil channels and consequent transmission failure.

Let me (us) know how it goes, I have been following silently but felt I should put in this word

Thanks for the advise man. I will share the outcome here.....

This is still ongoing.......

My valve body was taken out, cleaned, compression springs retentioned, bores cleaned, but problem persisted.

Solenoids were replaced, but problem persisted. Tech kept saying nothing is wrong with the transmission.

Another working valvebody installed, and problem got worse - vehicle jumping between gears, flares, disengagement, sudden shift to first gear from wherever.

Output speed sensor replaced, problem persisted.

Another valve body installed, same wahala. Tech took transmission down, and took it apart. Said he found nothing wrong!

Tech recommended another fluid flush, but I would take that no more!

I ordered for a replacement transmission, which from my checks should work perfectly. Transmission installed, 90% of symptoms continue!

A seemingly perfect transmission is already burning the fluid!!!!!

Transmission seller changed tech and yesterday, this new tech told me that my transmission annex connector is corroded; that is the problem all the while. Anybody heard about this before?

That's my story so far....

Kashif:
This is still ongoing.......

My valve body was taken out, cleaned, compression springs retentioned, bores cleaned, but problem persisted.

Solenoids were replaced, but problem persisted. Tech kept saying nothing is wrong with the transmission.

Another working valvebody installed, and problem got worse - vehicle jumping between gears, flares, disengagement, sudden shift to first gear from wherever.

Output speed sensor replaced, problem persisted.

Another valve body installed, same wahala. Tech took transmission down, and took it apart. Said he found nothing wrong!

Tech recommended another fluid flush, but I would take that no more!

I ordered for a replacement transmission, which from my checks should work perfectly. Transmission installed, 90% of symptoms continue!

A seemingly perfect transmission is already burning the fluid!!!!!

Transmission seller changed tech and yesterday, this new tech told me that my transmission annex connector is corroded; that is the problem all the while. Anybody heard about this before?

That's my story so far....

Any codes?

I once replaced a perfectly functioning transmission* as a result of two trouble codes, and two weeks later, same problem returned, so I said this time around, I won't replace it. That there has got to be another way.

* shifted well but won't enter overdrive, all other functions were right

I found a highly recommended transmission/ecu electrician who told me the vehicle has electrical problems, and after 2 days of tracing all the wiring and fixing the problem, my transmission issues were resolved.

I think breaking the vehicle breakdown analysis into mechanical, electrical, etc without some sort of collaboration among the various folks makes troubleshooting harder.

Maybe the vehicle/transmission has got electrical faults but your previous mechanic is going about it mechanically... just a guess... an an enthusiast, not a specialist

I once personally fixed my transmission issues by tracing the wiring and discovering there was no ground, but I wasn't capable of fixing this one because it involved the wiring harness leading to the ECU, and I had already lost one week trying to personally patiently troubleshoot the issue at the expense of a contract with much larger financial stakes than the value of the transmission and the labour to fix it by those who do it day day out, so in the end I decided to contract it out and I am happy I did because the issue was sorted out in less than 12 hours spread across 2 days

IdaraCHODB:

Any codes?
I once replaced a perfectly functioning transmission* as a result of two trouble codes, and two weeks later, same problem returned, so I said this time around, I won't replace it. That there has got to be another way.
* shifted well but won't enter overdrive, all other functions were right
I found a highly recommended transmission/ecu electrician who told me the vehicle has electrical problems, and after 2 days of tracing all the wiring and fixing the problem, my transmission issues were resolved.
I think breaking the vehicle breakdown analysis into mechanical, electrical, etc without some sort of collaboration among the various folks makes troubleshooting harder.
Maybe the vehicle/transmission has got electrical faults but your previous mechanic is going about it mechanically... just a guess... an an enthusiast, not a specialist
I once personally fixed my transmission issues by tracing the wiring and discovering there was no ground, but I wasn't capable of fixing this one because it involved the wiring harness leading to the ECU, and I had already lost one week trying to personally patiently troubleshoot the issue at the expense of a contract with much larger financial stakes than the value of the transmission and the labour to fix it by those who do it day day out, so in the end I decided to contract it out and I am happy I did because the issue was sorted out in less than 12 hours spread across 2 days

My brother, no be small thing. There was P07660 - points to SL2 malfunction......

Frustration leads to new names

Transmission seller changed tech and yesterday, this new tech told me that my transmission annex connector is corroded; that is the problem all the while. Anybody heard about this before?

there is no such name. seller should replace transmission, not the tech, next thing they might tell you is that your transmission ecu is bad to avoid the guarantee on transmission.

GAZZUZZ:
Frustration leads to new names there is no such name. seller should replace transmission, not the tech, next thing they might tell you is that your transmission ecu is bad to avoid the guarantee on transmission.

I am thinking same too but, I have made some observations:

1. Before the transmission was installed, the fluid that came out was clean, and absolutely free from any foul odour.

2. A day after installation, the new transmission was burning the fluid again (just like mine did)!

3. I have checked up this transmission, and it came off a 2008 Rav which was accidented in July last year. Rolled over and airbag deployed. Transmission was in good shape.

4. This replacement transmission has now 90% symptoms of the replaced one.

5. Nothing was wrong with my transmission initially before the differential check/fluid flush.


Somehow, I think there is an underlying electrical problem with the vehicle. The reason the seller decided to change tech, which I have always asked for, was that the first guy was delaying, telling stories.

5. Nothing was wrong with my transmission initially before the differential check/fluid flush.

You summed it up.

GAZZUZZ:

You summed it up.

So?

Kashif:


So?

You are smarter than this nah. If there was nothing wrong mechanically until it was mechanically worked on, then there's nothing wrong electrically. Did you do an ecm reset after replacement? (I'm sure u did)



I hope you will not sell that car out of frustration.

GAZZUZZ:

You are smarter than this nah. If there was nothing wrong mechanically until it was mechanically worked on, then there's nothing wrong electrically. Did you do an ecm reset after replacement? (I'm sure u did)
I hope you will not sell that car out of frustration.

Assuming there was something wrong with the former transmission, it has been replaced. This should have eliminated whatever mechanical issue faced. This one also slips at 2-3. What could have happened to a working transmission in less than three hours of aggregate use after installation? I got this transmission myself, and carried it to the installer. Something is causing the car to burn transmission fluid! The fibre (disk) was replaced in the former one, and it was burning again before I had the trans changed.

Yes, a TCM reset was done after installation.

Selling the car is not an option bro.

Kashif:
Guys, I asked my mechanic to flush my Rav4 V6 transmission, and the trans now malfunctions.

Shifts well but slips on 4-5. The technician says its the solenoid switches but I really do not agree. My reason - there has been a swap but the issue remains. The fluid was burnt, hence my reason for a flush. There was no issue after the flush until the filter was replaced. This problem now is an improvement from slippage on 2-3, and erratic shifting. According to him, the replaced solenoids were responsible for the improvement. If so, why does it not fully cure the trans? I have seen him rebuild transmissions but I tend to disagree with this.

I have read someone who had failed solenoids on same trans, but replacing them did not solve it, though his issues were more than mine. A rebuild, and later, reset of the trans ECM settled it.

Since the fluid was burnt, could there be some underlying problems? I don't want to throw money away buying wrong parts. Any ideas?

Thanks.

You shold not have allowed your transmission fluid to get burnt in your car before flushing it.

You would have to get it rebuilt or buy another transmission.

Kashif:


Assuming there was something wrong with the former transmission, it has been replaced. This should have eliminated whatever mechanical issue faced. This one also slips at 2-3. What could have happened to a working transmission in less than three hours of aggregate use after installation? I got this transmission myself, and carried it to the installer. Something is causing the car to burn transmission fluid! The fibre (disk) was replaced in the former one, and it was burning again before I had the trans changed.

Yes, a TCM reset was done after installation.

Selling the car is not an option bro.

You still got your self a defective transmission. Return it if you can and collect another one. ask the dealer to give you his own installer in a case where your own installer keeps doing something wrong.

Having read some opinions above, I have an alternative viewpoint.

I would say don't dismiss electrical fault as of yet P0766 is clearly an electrical fault relating to a shift solenoid.

I had a similar problem, although I never flushed my transmission and I think it is just not worth it to flush a transmission.

I replaced one transmission for another - the same problem cam back two weeks later.

Two codes - one that had to do with the input speed sensor and one that had to do with a shift solenoid.

I replaced the input speed sensor and the code went away but the one that had to do with the shift solenoid refused to go. Then after some days that input speed sensor died and I had to replace it with another, I knew something was wrong!

I went to a mechanic and asked him for a specialist in repairing electrical faults in the transmission but he gave me no reasonable suggestions other than that I should remove the thermostat that overheat is causing the components inside the transmission to fail; I went to the parts seller, he said time to change the transmission, but I ignored him; I also went to my preferred transmission repair shop and they told me I had an electrical fault (but I choose to disbelieve/disagree, especially since I have had a prior experience with their ecu/transmission electronics specialist who is as proud as he is gifted, and did I not just replace the transmission which worked well for 2 weeks and then kaput!), so I went to alldatadiy and it explained why I am having the codes.

After severally trying to find a car electrician that would be willing to use the printed alldatadiy guides to isolate the problem and failing because as soon as they heard transmission, they opted out of working with me, I decided to fix the problem myself. The problem was I have ordered for a professional level multimeter but it is not yet here so I was to some extent flying blind!

I spent a week, draining the ATF, replacing various shift solenoids all by myself, allowing the ATF to cool, tearing it apart again, changing the input speed sensor, dropping and cleaning the valve body without any improvement, then I decided, so how much time I have taken away from my business? This has got to stop!

That is when I went to the transmission repair shop the second time (hiding my face in shame sort of, well kidding) and then went back to the foreman to complain ( as if I did not know its an electrical fault, and is if I don't know the electrical guy myself)

I was then directed to him

The first day he spent nearly 6 hours troubleshooting the problem before deciding something is wrong with the wires that carry commands to and from the transmission to the ecu, by this time it was almost 5pm and I had to leave, he asked me do I want to go with the car or do I want to bring it back, I choose to bring it back.

The next week I brought the car and he and his team had after nearly 6 hours of carefully tracing cables that ran to the ECU from the transmission found and resolved the work.

He refused to tell me what he did to solve it, but I already know because alldatadiy told me. Do I really need to know how to do it? If I know what the problem is and who can solve it? That was the question on my mind after 1 week of trial and failure viz a viz the economic cost of DIY versus handing over to a professional.

Honestly, if you were in the car and heard the way it would change gears you would swear it was a mechanical fault. I also nearly swore I had a bad transmission BUT as it turns out the car is a delicate machine with a sensitive interplay of mechanical, hydraulic and even electronic/electrical components.

I would not after the above humbling lesson denigrate any lead until I solve the problem! It might be electrical afterall!!

Possible causes
- Low transmission fluid level
- Dirty transmission fluid
- Faulty shift solenoid 'D' valve
- Shift solenoid 'D' valve harness or connectors
- Shift solenoid 'D' valve circuit is open or shorted

Read more: http://engine-codes.com/p0766.html#ixzz3RXNMwYMD

IdaraCHODB:
Having read some opinions above, I have an alternative viewpoint.
I would say don't dismiss electrical fault as of yet P0766 is clearly an electrical fault relating to a shift solenoid.
I had a similar problem, although I never flushed my transmission and I think it is just not worth it to flush a transmission.
I replaced one transmission for another - the same problem cam back two weeks later.
Two codes - one that had to do with the input speed sensor and one that had to do with a shift solenoid.
I replaced the input speed sensor and the code went away but the one that had to do with the shift solenoid refused to go. Then after some days that input speed sensor died and I had to replace it with another, I knew something was wrong!
I went to a mechanic and asked him for a specialist in repairing electrical faults in the transmission but he gave me no reasonable suggestions other than that I should remove the thermostat that overheat is causing the components inside the transmission to fail; I went to the parts seller, he said time to change the transmission, but I ignored him; I also went to my preferred transmission repair shop and they told me I had an electrical fault (but I choose to disbelieve/disagree, especially since I have had a prior experience with their ecu/transmission electronics specialist who is as proud as he is gifted, and did I not just replace the transmission which worked well for 2 weeks and then kaput!), so I went to alldatadiy and it explained why I am having the codes.
After severally trying to find a car electrician that would be willing to use the printed alldatadiy guides to isolate the problem and failing because as soon as they heard transmission, they opted out of working with me, I decided to fix the problem myself. The problem was I have ordered for a professional level multimeter but it is not yet here so I was to some extent flying blind!
I spent a week, draining the ATF, replacing various shift solenoids all by myself, allowing the ATF to cool, tearing it apart again, changing the input speed sensor, dropping and cleaning the valve body without any improvement, then I decided, so how much time I have taken away from my business? This has got to stop!
That is when I went to the transmission repair shop the second time (hiding my face in shame sort of, well kidding) and then went back to the foreman to complain ( as if I did not know its an electrical fault, and is if I don't know the electrical guy myself)
I was then directed to him
The first day he spent nearly 6 hours troubleshooting the problem before deciding something is wrong with the wires that carry commands to and from the transmission to the ecu, by this time it was almost 5pm and I had to leave, he asked me do I want to go with the car or do I want to bring it back, I choose to bring it back.
The next week I brought the car and he and his team had after nearly 6 hours of carefully tracing cables that ran to the ECU from the transmission found and resolved the work.
He refused to tell me what he did to solve it, but I already know because alldatadiy told me. Do I really need to know how to do it? If I know what the problem is and who can solve it? That was the question on my mind after 1 week of trial and failure viz a viz the economic cost of DIY versus handing over to a professional.
Honestly, if you were in the car and heard the way it would change gears you would swear it was a mechanical fault. I also nearly swore I had a bad transmission BUT as it turns out the car is a delicate machine with a sensitive interplay of mechanical, hydraulic and even electronic/electrical components.
I would not after the above humbling lesson denigrate any lead until I solve the problem! It might be electrical afterall!!
Possible causes
- Low transmission fluid level
- Dirty transmission fluid
- Faulty shift solenoid 'D' valve
- Shift solenoid 'D' valve harness or connectors
- Shift solenoid 'D' valve circuit is open or shorted
Read more: http://engine-codes.com/p0766.html#ixzz3RXNMwYMD

Thanks for sharing this. I also believe there is some electrical problem somewhere. I have the repair manual of this transmission, and there is no complete match of what I am experiencing with it!

A transmission was working before the car was accidented. This transmission was installed in my car and gets fried?

@IdarCHODB, can I have the contact of your specialist, just in case?

DECOtech:
You shold not have allowed your transmission fluid to get burnt in your car before flushing it.
You would have to get it rebuilt or buy another transmission.
You still got your self a defective transmission. Return it if you can and collect another one. ask the dealer to give you his own installer in a case where your own installer keeps doing something wrong.

I am not careless with cars. Something acute came upon the car. If you had read through my posts, you would see that I am using the seller's preferred tech. Do you rebuild transmission BTW?