GX460 P2714 P0761 Ultimate Summary and Hope For A Fix Thread

[gsi18867]

Today’s update: drained pan, 5.5 QTs. Pulled pan. Pulled S3 C and S4 D solenoids. Performed bench test for resistance and action. S3 13-14 ohms. S4 14-15+ ohms, little high. refill with exactly 5.5 QTs. Leveled truck. Wouldn’t go into reverse off ramps, so had to push off. Brought up trans temp to 115 on low gauge, 118 on high gauge. Opened level drain and out came … almost 3 QTs. I’m very confused on how much fluid is in this damn thing. I should have only pulled out 1 Qt.

Test drive: initially still no reverse. Beautifully shifted 1-6 gears up and down. No hesitation, slip, nothing. Great! Get back home. Drops into reverse after 1 second delay. Park in driveway running to move another Toyota. Drops into reverse after 3 seconds.
So after everything, I’ve improved forward driving shifts. Back to major problems with reverse. Now I’ll go study up on the relationship between SL1, SL2, SLU, SLT to S3/S4. Because I regained 4th gear but lost more reverse capability. It could be a S4 ohm problem. It could be a pressure issue from one of the non shift solenoids.

Fluid was pretty clean, since I just filtered last night. Solenoids clean. I filled the S3 and S4 with cleaning fluid before activating with a 9V battery to clean around the mandrel as much as possible. Magnets were pretty dirty for just yesterday’s test drive. Getting more junk out.

 

[StriderWolf]

Today’s update: drained pan, 5.5 QTs. Pulled pan. Pulled S3 C and S4 D solenoids. Performed bench test for resistance and action. S3 13-14 ohms. S4 14-15+ ohms, little high. refill with exactly 5.5 QTs. Leveled truck. Wouldn’t go into reverse off ramps, so had to push off. Brought up trans temp to 115 on low gauge, 118 on high gauge. Opened level drain and out came … almost 3 QTs. I’m very confused on how much fluid is in this damn thing. I should have only pulled out 1 Qt.

Test drive: initially still no reverse. Beautifully shifted 1-6 gears up and down. No hesitation, slip, nothing. Great! Get back home. Drops into reverse after 1 second delay. Park in driveway running to move another Toyota. Drops into reverse after 3 seconds.
So after everything, I’ve improved forward driving shifts. Back to major problems with reverse. Now I’ll go study up on the relationship between SL1, SL2, SLU, SLT to S3/S4. Because I regained 4th gear but lost more reverse capability. It could be a S4 ohm problem. It could be a pressure issue from one of the non shift solenoids.

Fluid was pretty clean, since I just filtered last night. Solenoids clean. I filled the S3 and S4 with cleaning fluid before activating with a 9V battery to clean around the mandrel as much as possible. Magnets were pretty dirty for just yesterday’s test drive. Getting more junk out.

Wow! If you had a YouTube channel, I’d subscribe! Super thorough, checking many items being methodically evaluated. You are like Tinker’s Garage!

Thanks for contributing and what you are seeing is rather interesting as the cleaning and fluid changes is making things better.

 

[gsi18867]

Wow! If you had a YouTube channel, I’d subscribe! Super thorough, checking many items being methodically evaluated. You are like Tinker’s Garage!

Thanks for contributing and what you are seeing is rather interesting as the cleaning and fluid changes is making things better.

Thanks. I have some 50 micron sock filters coming in this week. That’ll be what I use from here on. Worst part about the whole process is properly bolting up and torquing the pan. Time consuming. What do you think of the ohms issue?

 

[StriderWolf]

Thanks. I have some 50 micron sock filters coming in this week. That’ll be what I use from here on. Worst part about the whole process is properly bolting up and torquing the pan. Time consuming. What do you think of the ohms issue?

That’ll be interesting to see what you filter out.

Do you suppose the new fluid and changes is getting out debris?

On the ohm issue, I don’t know much, but if that is the one acting up, who knows if that is the issue. I only mention as our transmission is fine after it warms up and they’ve tested the solenoids and the are fine… it doesn’t make a lot of sense. So we always suspected it was the heat expanding or creating pressure or some electrical issue front the transmission to the battery or ECU. But, not like I am getting in there like you.

What are your thoughts on the multiple fluid changes and the filtering you may be doing? Do you think the system simply has too many particulates in it? Why else would you get gears back or better use?

 

[gsi18867]

That’ll be interesting to see what you filter out.

Do you suppose the new fluid and changes is getting out debris?

On the ohm issue, I don’t know much, but if that is the one acting up, who knows if that is the issue. I only mention as our transmission is fine after it warms up and they’ve tested the solenoids and the are fine… it doesn’t make a lot of sense. So we always suspected it was the heat expanding or creating pressure or some electrical issue front the transmission to the battery or ECU. But, not like I am getting in there like you.

What are your thoughts on the multiple fluid changes and the filtering you may be doing? Do you think the system simply has too many particulates in it? Why else would you get gears back or better use?

On filtering, removing anything that is not clean fluid can’t hurt. I see it as an easy cheap way to eliminate variables. Anything that could restrict parts movement has to go.

Tomorrow morning will be a cold start experiment to see if all forward gears remain trouble free. Could the temp increase after the truck warms up reduce the ohms? Does a temp increase expand the solenoid casing enough for the mandrel to function with lower resistance? Could a looser solenoid wire connection cause a drop in voltage transmission just enough for the higher ohms to be a problem? I have considered an ECU problem, but a lower voltage for just one solenoid? I’m not an electrical engineer. My background is petroleum, so I approach fluid first , then mechanical issues.

I’m slowly going towards replacing just the one solenoid. Even if I have to do it every year, it’s a better solution for me.

 

[gsi18867]

Today’s update. No reverse on cold start or after warming up in driveway for 5 minutes. Reverse after 10 second delay after driving 5 miles. Reverse within 1-3 seconds after that. Almost like the reverse solenoid isn’t getting fluid. The longer I go not using reverse, the longer it takes to get reverse back. Fluid draining out of the solenoid input channel?

Still concerned about dumping 3 QTs last night. I’m going to add 2 QTs tonight and perform fluid check again.

Still have all forward gears but with a little higher shift points, like they are delayed, after cold starts. Similar to putting a pick up truck into tow/haul mode or putting a LX450 into “PWR” mode. I’m fine with this, I actually like it.

 

[gsi18867]

I want to retest S4 to double check ohms reading, and pull SLT to bench test. It seems like there’s either not enough pressure to activate S4 or too much resistance in S4. This is in preparation to replace just one solenoid with a new Toyota original

 

[StriderWolf]

Today’s update. No reverse on cold start or after warming up in driveway for 5 minutes. Reverse after 10 second delay after driving 5 miles. Reverse within 1-3 seconds after that. Almost like the reverse solenoid isn’t getting fluid. The longer I go not using reverse, the longer it takes to get reverse back. Fluid draining out of the solenoid input channel?

Still concerned about dumping 3 QTs last night. I’m going to add 2 QTs tonight and perform fluid check again.

Still have all forward gears but with a little higher shift points, like they are delayed, after cold starts. Similar to putting a pick up truck into tow/haul mode or putting a LX450 into “PWR” mode. I’m fine with this, I actually like it.

I am curious what adding 2 quarts will do.

 

[gsi18867]

I am curious what adding 2 quarts will do.

I believe the original fill level was only 1 qt over. But yesterday’s fill check spit out 3 QTs. If I’m not getting enough fluid to the reverse solenoid from the pressure solenoid, or starving the pressure solenoid, air in the line may prevent building enough pressure for the reverse solenoid. If the reverse solenoid has higher ohms (resistance), it may require more pressure to properly function.

 

[DUDEINAGARAGE]

Welp toyota came back today and is throwing same codes but only hiccups with them not full stop so builder is taking a stab at putting lubeguard in to try and resolve the stucks valve if its still sticking. I dont do any of the work just trying to help relay what we try and what we find here.

Keep in mind other than the customer not having their car we are taking on these issues at our expense not theirs. Im just trying to keep customers happy and with jobs like these its rough on everyone.

 

[gsi18867]

Welp toyota came back today and is throwing same codes but only hiccups with them not full stop so builder is taking a stab at putting lubeguard in to try and resolve the stucks valve if its still sticking. I dont do any of the work just trying to help relay what we try and what we find here.

Keep in mind other than the customer not having their car we are taking on these issues at our expense not theirs. Im just trying to keep customers happy and with jobs like these its rough on everyone.

How much success have you had with lubeguard?

 

[gsi18867]

Welp toyota came back today and is throwing same codes but only hiccups with them not full stop so builder is taking a stab at putting lubeguard in to try and resolve the stucks valve if its still sticking. I dont do any of the work just trying to help relay what we try and what we find here.

Keep in mind other than the customer not having their car we are taking on these issues at our expense not theirs. Im just trying to keep customers happy and with jobs like these it’s rough on everyone.

How much success have you had with lubeguard? The reason I ask is that I just took mine for a cold start test drive. Reverse worked great right at startup. Once the transmission got over 150 F, I lost reverse and it threw codes. This was after using reverse 4-5 times and running it around for a few minutes. Looking like a pressure/resistance/possibly a viscosity problem. What additives help increase viscosity/capillary pressure (I dont know the automotive term)

 

[DUDEINAGARAGE]

How much success have you had with lubeguard?

Well we ran three test drives on the Toyota and so far it's doing what it's supposed to so one with this transmission that I've been a part of. Customer has been notified and is ok with picking up for time being we'll see how long it lasts before replacement but also customer knows to bring it by for trans service regularly.

Trying the Lexus seeing if it helps at all.

 

[DUDEINAGARAGE]

What most of the talk here has boiled down to on the trans is too long of a term without service allowing the viscosity of the trans fluid + detergents running thin in the heat causing problems with the colder temps and just cascading effects. (Is this the true answer or resolve?) No. But we believe it to be a major factor in figuring it out. Will post an update today on the now lubegaurded lexus

 

[gsi18867]

What most of the talk here has boiled down to on the trans is too long of a term without service allowing the viscosity of the trans fluid + detergents running thin in the heat causing problems with the colder temps and just cascading effects. (Is this the true answer or resolve?) No. But we believe it to be a major factor in figuring it out. Will post an update today on the now lubegaurded lexus

Thank you for your opinion. After much more research, I don’t believe continual filtering of my fluid is a good way to go.

 

[DUDEINAGARAGE]

I apologize for the delay in updates..

7 test drives and putting quite a few miles on the Lexus she seems to be running like a dream. Customer is picking up soon and knows to keep us informed if i see either one back ill be back on here with more updates DUDE, out.

 

[gsi18867]

Anybody have experience replacing solenoids with cheap aftermarket replacements?

 

[yeLwWm]

Anybody have experience replacing solenoids with cheap aftermarket replacements?

Try Rostra solenoids

 

[BlkGX2011]

Ive been running lubegaurd after replacing just the transmission pan fluid. Its been maybe 2 months and its only slightly improved my symptoms (delayed reverse, some slipping). I thought it would eliminate the codes from showing up but that has not been the case.
I still have the new (reman) unit to swap in some time this month.
If i have time, I'll direct the old transmission to take a look at the clutches.

 

[gsi18867]

Ive been running lubegaurd after replacing just the transmission pan fluid. Its been maybe 2 months and its only slightly improved my symptoms (delayed reverse, some slipping). I thought it would eliminate the codes from showing up but that has not been the case.
I still have the new (reman) unit to swap in some time this month.
If i have time, I'll direct the old transmission to take a look at the clutches.

How delayed is your reverse? Sometimes when it’s cold I don’t have it at all. Sometimes I have to bring the engine to 4K RPMs and hold it for a few seconds. Waiting for the transmission to warm up doesn’t help. Most of the time it’s 1-3 seconds after it’s been driven for at least 15 minutes. Seems to be a pressure/temperature/fluid flow flow problem.