Need Transmission advise, have valve body out

[Skidoo]

As I mention in earlier post I am getting a P0770 code (TC lockup malfunction) It can happen a couple of days apart, but then it did "not" happen on a 10 day 2000 mile trip to southern Utah for off-roading.
Have a number of photos during various stages ofdisassembly at this site.
Picasa Web Albums - H2O - Land Cruiser A/T
(Clicking on photos will get you larger views.)
As mentioned in other post, will write this up when done. Have started to label things in photos I don't find in manuals.

I have tested Lockup Solenoid with compressed air and it tests good. Of course since it is intermittent behavior, expect should replace it anyhow.

Questions:
1. The amount of metal shown in pan, good, bad, ugly?
2. Various screens look pretty clean?
3. Anything I should be looking for in lockup circuit?
4. Am I correct in assuming that Torque Converter lockup failing would create a lot of metal in the pan?

2000 Land Cruiser, 143K miles, manufactured July 2000.

Thanks,
Skidoo

 

[NMuzj100]

1. The amount of metal shown in pan, good, bad, ugly?
Looks normal to me.
2. Various screens look pretty clean?
They looked pretty good.
3. Anything I should be looking for in lockup circuit?
I have no idea, sorry.
4. Am I correct in assuming that Torque Converter lockup failing would create a lot of metal in the pan?
I don't think so. I think it would create excessive heat and burning fluid. Your fluid looks good. (FYI - I'm not an AT expert)

Are the check balls held in with anything or do they just float in their chambers ?

Great pictures!

I attached a few for posterity
1. Labeled Valve body
2. AT w/ valve body removed
3. Upper valve body w/check ball positions.

 

[wildsmith]

Has it ever given you the opposite fault and stayed locked when it shouldn't? I don't think the washer failing in the TC creates much material evidence until it gets really bad but I don't *know* that.

It could also be a wiring fault in the harness to the gearbox. Is there a different code for solenoid failure vs lockup failure?

 

[Skidoo]

The plate that goes between Upper and Lower Valve Bodies keeps balls in place and also provides seats for balls work against. When disassembling Valve Body, Upper Valve is on top to remove bolts. Carefully separate Plate from Lower Valve Body and hold it tight against Upper Valve Body while flipping Upper Valve Body over to keep balls in place, then Plate can be removed.

No, I have never had it fail with lockup on.
There are two codes P0770 and P0773 for Lockup Solenoid, I am just seeing the P0770 code.
P0770 detection is; Lock-up not occuring in lock-up range (50mph) or Lock-up remaining on outside lock-up range. (2 trip detection logic)
P0773 detection is; Solenoid resistance is 8 ohms or less when energized or is 100K ohms or more when not energized.

 

[wildsmith]

I guess it's not a wiring fault then or you'd have a P0773 code as well. When it fails to lock does it keep failing for a while or work as normal right away?

I would change the solenoid but resign myself to the thought the TC may need changing to fix it. I had lock up problems on my 80 a few years ago and went through a similar process

 

[Skidoo]

Decided to have valve body modified by IPT for improved shifting and pressures while it is out. NMuzj100 suggested a valve body by Wholesale of Australia, but in looking around IPT has a good reputation and costs less. Will know more when it gets back.

 

[Texasoil]

The failure to work IN THE PROPER SPEED RANGE is indicative of a speed sensor failure. If the solenoid was not working--you would probably get the other error code (presuming you have checked the resistance and it is OK--however, the tolerance range shown is ridiculously wide by the way. I would replace the bugger.It could be a simple bad electrical connection from the speed sensor to the transmission computer. break that connection, inspect it, and then apply 'Stabilant 22' to all th epins and reconnect.

 

[Skidoo]

Thanks, I had not thought of the speed sensor, I will follow up on your suggestions.

 

[Brexploration]

Just ran across this issue. Hoping you were able to fix it and how you did it?

 

[Skidoo]

The valve body modified by IPT works great. The P0770 code still pops up once in a great while and since I have a ScanGuage just clear it. Expect the speed sensor is dying a slow death and will one day replace it. Once cleared the code does not come back for as much as a year, so not a priority.

 

[ponytl]

As I mention in earlier post I am getting a P0770 code (TC lockup malfunction) It can happen a couple of days apart, but then it did "not" happen on a 10 day 2000 mile trip to southern Utah for off-roading.
Have a number of photos during various stages ofdisassembly at this site.
Picasa Web Albums - H2O - Land Cruiser A/T
(Clicking on photos will get you larger views.)
As mentioned in other post, will write this up when done. Have started to label things in photos I don't find in manuals.

I have tested Lockup Solenoid with compressed air and it tests good. Of course since it is intermittent behavior, expect should replace it anyhow.

Questions:
1. The amount of metal shown in pan, good, bad, ugly?
2. Various screens look pretty clean?
3. Anything I should be looking for in lockup circuit?
4. Am I correct in assuming that Torque Converter lockup failing would create a lot of metal in the pan?

2000 Land Cruiser, 143K miles, manufactured July 2000.

Thanks,
Skidoo

I would bet it's the speed sensor... about any toyota one will work if you just want to test it... you might have to enlongate the mounting hole... but I bet that will fix your problem... less than $20 on ebay