P0765 Shift Malfunction '01 Es300

[GrayES300]

Hey guys,

I've been searching the forums and found some information about P0765 codes and what to do. I'm going to try to fix this myself, but need some support to get the guts to go through with this. Here are the details:

My car, '01 ES300 with only 250k miles would shift into overdrive and shift back out. The check engine light came on. Scanned and got the P0765 which appears to be a malfunction in the solenoid D on the valve body. I change the fluid out of the pan every 20k miles. I have dropped the pan a couple of times also to clean out and just had the normal metal powder on the magnets. Fluid never smelled burned and always was still a good color before being replaced. Never had a tranny flush by a mechanic. Trans was performing fine until this point. Car still drives fine, but won't be very fuel efficient without overdrive. All other gears shift fine.

Here are my questions:

I've read here that most people need to replace the transmission because it is failing or at least the valve body. I want to try just the solenoid first with a cleaning of the valve body.

1. Am I crazy and just wasting my time and money?

2. Is the solenoid electrically controlled? Can it simply just wear out without it being shavings preventing it from functioning?

3. Is there a way to test the solenoid to see if it is stuck without removing it? How about if it is removed, can I test it with simple tests (I do not have a multi-tester)

4. Is there a source for generic solenoids outside of a Lexus dealer? Do Camry's use the same part that might be cheaper at a Toyota dealership instead of Lexus?

5. Are there any gaskets that need to be replaced on the valve body before reinstalling?

6. What should I use to clean out the valve body? Just normal parts cleaner?

The only experience I have had with removing a valve body was on a '51 Packard. From the pictures I have seen, they look similar, except the Lexus has wires. I just want to be more prepared before ripping into my car.

Any help would be greatly appreciated!

[lenore]

the tell tale will be when you pull the pan. See if there is a lot of metal debris in the pan. I have personally removed the valve body for that exact code. Something was failing mechanically and the valve body had debris in it. You can clean the valve body with Mineral spirits. It is safe for the tranny when cleaning. I suspect your planetary gears are failing and contaminated the solenoid. Dont do a flush, it will make it worse. Good luck the solenoid is electrically controlled. Tolerances are extremely tight and any contaminants will mess up the valve body....Could be the solenoid is working, but the piston wont move.

[GrayES300]

Was your transmission shot or were you able to clear out the valve body to fix it? Thanks for the advice on the mineral spirits. Do the solenoids ever fail on their own without it being clogged? Hopefully I'll have time this weekend to take it apart and check it out.

[lenore]

Unfortunately, the valve body cleaning did not fix it, had to replace the tranny, too much metal debris damage. suspect the planetary gear carrier wore out. The original design incorporated an aluminum carrier with steel gears. The gears shaft wears in the carrier and start moving, causing failure of the gears.

[GrayES300]

BUMP...I wrote this post in May. I have finally gotten around to working on the car and had some questions. Lenore was helpful originally. Maybe Lenore or someone else could give me more specific details on the actual cleaning process of the valve body. My thought was to take the solenoids off and clean the pistons and inside the cylinders with mineral spirits (lenore recommended). Will this be sufficient or should I soak the entire assembly? Are there other parts I should take off the valve body to clean? Should I spray carb cleaner or something on the gears that were exposed when removing the valve body, or just leave it alone?

So far, I have removed the pan (no abnormal metal shavings, just usual powder on the magnets. Trans fluid was medium brown and did not smell burnt). Definately time to change it anyway. I now have the valve body out (surprised when a piston and two springs popped out of the top of it). If I remove a solenoid, can I test it somehow? Maybe hook it up to the battery with jumper wires and aligator clips to see if it moves, or would that damage it?

Any help/advice would be appreciated.

Thanks

[GrayES300]

Haven't gotten any advice on this. I soaked the solenoids in mineral spirits for a while and washed the valve body with it also. I'm not going to try to "test" the solenoids because I'm not sure if hooking it directly to the battery would burn it out or not.

Does anyone have some tricks for reinstalling the valve body? I'm nervous about trying to get the check ball valve and the spring and pistons all to stay in place while fumbling to get some of the bolts back in. Maybe someone who has done this before has a system for doing it easier?