P0770: Deciding on repair options

[fourfive]

So your gameplan is to change the solenoids and 1 gallon of fluid and see how it does?

For the most part yes but I'm actually wanting to test the solenoids following the fsm steps first. I started draining my atf last night & will remove the pan tomorrow to expose the solenoids. Only problem is I have no idea which of the 3 solenoids is the "shift solenoid valve SL" or "shift solenoid E". I've been flipping through my fsm & trying to google the location of that solenoid since last night but haven't had any luck. If I still don't know which solenoid I'm supposed to test I'm just going to order all 3 & hope it works.

While I have the pan down I was wanting to inspect the valve body because that's one of the areas the fsm said could be faulty but they didn't specify testing procedures. Any transmission peeps out there know how to diagnose a bad valve body?

 

[Dieselchessy]

AFAIK

SL = TCC =#3= Bigger expensive one, should be closer to front of vehicle.

The other two are similar (maybe bolt tab differs) and are the Shift 1/2.

Not positive what the (E) means to Toyota, but you need to look at the TCC solenoid.

 

[brillo_76]

For the most part yes but I'm actually wanting to test the solenoids following the fsm steps first. I started draining my atf last night & will remove the pan tomorrow to expose the solenoids. Only problem is I have no idea which of the 3 solenoids is the "shift solenoid valve SL" or "shift solenoid E". I've been flipping through my fsm & trying to google the location of that solenoid since last night but haven't had any luck. If I still don't know which solenoid I'm supposed to test I'm just going to order all 3 & hope it works.



While I have the pan down I was wanting to inspect the valve body because that's one of the areas the fsm said could be faulty but they didn't specify testing procedures. Any transmission peeps out there know how to diagnose a bad valve body?

Unfortunately, I am no help to you there. I only clean my magnets. Change the atf metal screen and put the pan back on with a feel pro gasket. Then I exchange my fluid with my homemade bucket exchanger system.


However, eventually I am sure I have to rebuild one to do it and see exactly how they are made.

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[jgue467]

Got a pending P0770
...
The FSM says P0770 can be caused by:
-Shift solenoid valve SL is stuck open or closed
-Valve body blocked up or stuck
-Lock-up clutch/torque converter issue
3.
...

Since the FSM has narrowed P0770 to a few areas,

FSM P0770 & solenoid testing procedure:
http://www.teamtoyota4x4.org/archiv...ypdf/02rmsour/2002/024runne/di/at/cip0770.pdf
[/url]

FSM says the valve SL needs to be tested with air presssure (71psi) First. It is THE suspect culprit per the FSM. If it passes, the you check the valve body and so on. Have you had a chance (or maybe i missed it) to check the valve for air pressure holding?

 

[Prime30668]

I'm calling the fuel pump. Everything else would probably cause a CEL? Also...why'd you post in a transmission thread?

I just made this account and I couldn’t find any recent posts and I also couldn’t make my on thread yet. Just trying to figure it out. But also I have no other issues with fuel, it will idle for as long as I leave it running just fine. I have a new fuel pump because that was my first thought of what it could be, but I haven’t changed it just because I don’t want to just keep changing parts that don’t need to be changed yet

 

[fourfive]

FSM says the valve SL needs to be tested with air presssure (71psi) First. It is THE suspect culprit per the FSM. If it passes, the you check the valve body and so on. Have you had a chance (or maybe i missed it) to check the valve for air pressure holding?

I'm wanting to test it but there's 2 problems...
1. I don't know which of the 3 solenoids is the valve SL.
2. Even if i know the location of the valve SL, I don't know which solenoids the part numbers apply to.

I think what I'll have to do is test all 3 & if they all pass then I can rule out the solenoids but if one of the solenoids fail, I'll have to buy all 3 to replace since I don't know which solenoids the part numbers apply to.

 

[fourfive]

From what I read in the fsm I think the testing procedures for the 3 solenoids are the same.

 

[fourfive]

Found the solenoid valve SL

 

[fourfive]

AFAIK

SL = TCC =#3= Bigger expensive one, should be closer to front of vehicle.

The other two are similar (maybe bolt tab differs) and are the Shift 1/2.

Not positive what the (E) means to Toyota, but you need to look at the TCC solenoid.

Just saw your post after finding it in the fsm. Thanks for the help.

 

[Dieselchessy]

TSB is better than some random guy.

I didn’t troubleshoot mine, just did swaptronics. Took out the OEM and installed amazon blue one. No more issue.

But I’ve done similar on 48Re’s so it wasn’t a new thing to me. They have the pressure sensor and solenoid fail rather often.

Of course I don’t have scientific evidence but I feel (literally) that valvoline max life ATF helps these older trannies, and Lucas stop slip don’t hurt either.
I’ve also ran the Redline atf, it didn’t seem to make a noticeable difference, maybe slightly more abrupt shifts.

 

[fourfive]

I didn’t troubleshoot mine, just did swaptronics. Took out the OEM and installed amazon blue one. No more issue.

But I’ve done similar on 48Re’s so it wasn’t a new thing to me. They have the pressure sensor and solenoid fail rather often.

Was it the solenoid valve SL that you swapped? What were your symptoms? Did you have p0770?

 

[Dieselchessy]

Was a while back, torque converter clutch errors, seeming failure of torque converter to let go, or to lock up off and on.
I think you have bigger problems. Perhaps your solenoid leaked and now your TC clutch is shot.


You will see, when you get into it, that these Solenoids just hold or release pressure. Fairly simple.

Maybe you will find yours leaks.

I think you have collateral damage though, from your description. TC might be toast, or worse.

 

[fourfive]

I think you have bigger problems. Perhaps your solenoid leaked and now your TC clutch is shot.

You will see, when you get into it, that these Solenoids just hold or release pressure. Fairly simple.

Maybe you will find yours leaks.

I think you have collateral damage though, from your description. TC might be toast, or worse.

Were there certain red flag symptoms that point to my torque converter being bad or my trans on its way out? Because if that's the case I'll go ahead and get a reman transmission from toyota.

 

[Dieselchessy]

I’m not an auto tranny guy. I hate the things. I want to shift when I want to shift.

Your description of noise, rattling, decreased power, elevated temps, indicates to me a physical mechanical issue. Not just a wonky solenoid.

Maybe your flex plate cracked, maybe the TC has failed, bearings, ect....

I think you should keep perspective and take steps in order.

It’s a pain to pull the tranny, an aftermarket solenoid is cheap and easy.
Toss one in. If nothing changes, then take things further.
I’m just guessing based on your descriptions, my comments shouldn’t be used to make high dollar decisions.

 

[fourfive]

I’m not an auto tranny guy. I hate the things. I want to shift when I want to shift.

Your description of noise, rattling, decreased power, elevated temps, indicates to me a physical mechanical issue. Not just a wonky solenoid.

Maybe your flex plate cracked, maybe the TC has failed, bearings, ect....

I think you should keep perspective and take steps in order.

It’s a pain to pull the tranny, an aftermarket solenoid is cheap and easy.
Toss one in. If nothing changes, then take things further.
I’m just guessing based on your descriptions, my comments shouldn’t be used to make high dollar decisions.

I don't know what your background is but you called it. Just dropped my pan and saw some good size metal shavings on my magnets. Ironic thing is when I checked my fluid a couple weeks ago it was bright red, was probably to early for the shavings to turn the fluid black. I guess this means my transmission has reached its end. Time to start shopping for a new one. I appreciate the help & I didn't take your comments in that way. In another thread I was actually asking if the symptoms I was experiencing were indications that my transmission was compromised.

 

[brillo_76]

How big are those shavings??

That looks like larger chunks on those magnets and not super fine paste metal.

I say your TC is damaged and possibly your transmission as well

Any TC noise is mostly TC damage.


The 3rd gen 4runner transmission removal isnt that bad. However, it's not a few hour job either.


So you have the option of changing the solenoids and replacing the TC and verify your Flexplate is good and see what it does

Or replacing the transmission and TC with a new flexplate to eliminate everything at once..


At least you know the cause or what the issues are. That's 90% of the fix.

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[jbtvt]

Might consider rebuilding yourself if you have time. I may even have a repair manual PDF for it. Or even just replacing the TC might do it. If you buy another used one you might be in the same boat in a few months. Don't know what reman ones go for it but can't be cheap.

 

[fourfive]

They're definitely larger shavings/chunks. Pretty sure I'm going to just replace the whole transmission, flexplate, etc.

 

[brillo_76]

I know I would change the TC verify the flexplate isnt cracked etc and put it back together.


If that TC had bearings starting to fail, that would explain the whining and noise and cause all that you were seeing.

If the truck was shifting properly, reverse good etc. Your solenoids are probably fine.

However, I am not a transmission expert. That's just what I am going to do with mine that has a failing TC.

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[brillo_76]

They're definitely larger shavings/chunks. Pretty sure I'm going to just replace the whole transmission, flexplate, etc.

That's a plan and should eliminate your problems.

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