GX460 P2714 P0761 Ultimate Summary and Hope For A Fix Thread

[gsi18867]

Buddy, just give up. I've tried many things, but the code always comes back. Save yourself some money and time, and let a transmission repair shop rebuild it.

Have you rebuilt the VB yet? I can’t find a rebuilt VB, but there’s a zip kit at a Sonnax distributor near me. I didn’t want to do it, but $300 is way better than $3500. I’m not paying $7K for a shop to do the swap. I’ll burn the truck and let insurance kick in before that.

Worst used vehicle I’ve ever bought, and I’ve bought old BMWs

 

[yeLwWm]

Yes, I have tried rebuild VB, new VB, all new solenoids. Nothing really worked.

 

[gsi18867]

Yes, I have tried rebuild VB, new VB, all new solenoids. Nothing really worked.

Sounds like fire is on the menu. But before I burn it, I’m going to rebuild the VB. $235 delivered from Rock Auto

 

[gsi18867]

Yes, I have tried rebuild VB, new VB, all new solenoids. Nothing really worked.

If the VB rebuild doesn’t work, I’ll be swapping in a Lexus rebuilt. Questions: did you happen to notice how snug the solenoids were in your old VB versus your new VB? Some of mine are tight, but a couple seem loose.

 

[BamaPaul]

BP, do you think it would be possible to loosen the VB enough, with completely removing, to push the plug keeper up while you remove the plug with a magnet? Do you think there may be enough room to push up the keeper without loosening the VB? How tough was it to get the plug moving?

View attachment 4055463

I think you will have to remove the VB

 

[gsi18867]

I think you will have to remove the VB

Thank you. I have a zip kit and green goop on the way. I’m going to do the whole thing. Fingers crossed but expecting no improvement. If I can just get reverse back without spooling up the engine I’ll call it a success.

 

[gsi18867]

The fun is about to begin

 

[gsi18867]

Finished up late last night. About a 8-10 hour process for someone who’s never really worked on transmissions. There is a sharp lip on the inside edge of the bore chamfers. This is what cuts the o rings. It has to be smoothed somehow. And it appears the chamfers act as a sealing edge on some of the plugs. On others, the o ring sits inside the bores.

Thank you @BamaPaul for all your photos and suggestions. . When the check valve fell out, the little spring took off. I got lucky and found it. Not sure how important it is, but Toyota put it in there for a reason. If you hadn’t mentioned it in your write up, I wouldn’t have been looking for it.

As someone else mentioned, Sonnax has an error on placement of one of the balls. And some of their VB bolt lengths are not correct. If you’re going to try this install, you need to stay very organized from the start. Every word in the instructions is important. Nothing can be skipped or rushed. Here are a few photos. This morning I will reset the transmission memory and set the correct fluid level.

 

[gsi18867]

2 hours with the battery unhooked followed by a long test drive. Cold start performance was initially poor. Had partial reverse out of the garage. Hanging on 2nd. Quickly remedied after about a mile. After a couple miles, fantastic forward gear shifts. It’ll hit TQ lockup much faster. Good performance. 2nd effort for reverse took 1 second to drop into full reverse. 3rd effort took 1/2 second. 4th time right into reverse. This was not out of the norm. I’ll check reverse again later today. I’m fine with a 1 second reverse delay as long as I don’t have to rev to 3K and it’s full power reverse. No codes. I left the fluid about 1 qt high. Was doing some reading about owners setting their own levels per the FSM and then the dealer saying they were 1.5 QTs low. Mine was running like hell after FSM fluid level set. And I got it 1.5 QTs high.

Will wait till I get through a few hundred miles before another update

 

[Biginboca]

I posted a while ago in this thread when my GX first had the codes about 2 years ago January 2024 141k miles (post #7 on page 1 of this thread) and I did Sport mode for about a year before losing reverse occasionally in January of 2025 at 154k.

At that time I parked the GX next to my driveway where it has sat until today, a year later. Luckily I have other cars. I’ve been following this thread hoping for some sort of new revelation for a simple fix. Well it’s clear there is no simple fix!

So I’m going to bite the bullet and start looking for a deal on a remanufactured transmission. I’m wondering if this is worth tackling as a diy job though? I’ve got decent mechanical skills having installed lift kits, fixed the valley plate leak myself, replaced driveshafts and axle shafts on cars before. I don’t have tech stream or access to it though. (As far as coding and any PC work goes I’m lost.). Is it just a nuts and bolts job or does it need some sort of computer work?

Also, for the tranny fill I assume if you are starting with a new dry transmission then the fill should be easy, just fill it to the capacity spec with no need to monitor temps and deal with fancy fill procedures?

Also does the torque converter come pre installed on the reman tranny?

 

[Acrad]

Yes.. it should include TC. I’ve heard the only old part is the transmission case. All internals should be new.

https://parts.belllexusnorthscottsdale.com/p/69296851/35010-35B70-84.html

 

[gsi18867]

About 500 miles into the Sonnax zip kit install. Don’t have to rev the engine to 3K to catch reverse. Usually a 1-5 second delay into reverse after the truck has been running. Cold mornings without warm up I don’t always have full power forward or reverse. This goes away within 100 yards. First 5 minutes of driving has lagging shifts, sometimes. Will hang in 3rd gear till 5K some mornings. Have to let off the gas and reapply for it to shift. This only happens once.

Overall, better because I now always have reverse, even if there’s a lag. Not great performance. Will run it like this until either a big Toyota sale or it forces me to replace the trans.

 

[thescreensavers]

I’m wondering if this is worth tackling as a diy job though? I’ve got decent mechanical skills having installed lift kits, fixed the valley plate leak myself, replaced driveshafts and axle shafts on cars before.

Also, for the tranny fill I assume if you are starting with a new dry transmission then the fill should be easy, just fill it to the capacity spec with no need to monitor temps and deal with fancy fill procedures?

Every job can be DIYed, especially since you have other vehicles id 100% DIY. May want to rent or buy a trans jack that would be super helpful.

When ever you are filling the transmission you always need to refill per the temp procedure. A $30 OBD Bluetooth device an OBD fusion on your phone and you'll have the temp readouts. Doing all that work and not refilling it correctly is crazy.

 

[ericm979]

I've done the level check at temperature for a number of transmissions now. It's not difficult. Often the hardest part is waiting for the trans to come up to temp.

 

[re_guderian]

...When ever you are filling the transmission you always need to refill per the temp procedure. A $30 OBD Bluetooth device an OBD fusion on your phone and you'll have the temp readouts. Doing all that work and not refilling it correctly is crazy.

Hard to believe that the factory assembly-line fill process involves getting every single brand new tranny up to temp instead of just filling with the prescribed amount out of the crate, no?

 

[gsi18867]

Anybody tried changing a GX transmission without using a lift? I have ramps/jacks/stands, but do not want to pay $3K in labor for something I can do in the garage

 

[thescreensavers]

Hard to believe that the factory assembly-line fill process involves getting every single brand new tranny up to temp instead of just filling with the prescribed amount out of the crate, no?

I do not disagree with your point but, there is a reason the procedure exists and all transmissions even with a dipsticks are measured while running and up to temp. Since Automatic transmissions are sensitive to the level being correct for proper operation I'm not sure why you'd want to shortcut a critical step in process.

All fluid capacites are approximate, the exact level is set via the temp method. Same way you do an oil change the dipstick has final say not what the manual says the capacity is.

 

[Biginboca]

I do not disagree with your point but, there is a reason the procedure exists and all transmissions even with a dipsticks are measured while running and up to temp. Since Automatic transmissions are sensitive to the level being correct for proper operation I'm not sure why you'd want to shortcut a critical step in process.

All fluid capacites are approximate, the exact level is set via the temp method. Same way you do an oil change the dipstick has final say not what the manual says the capacity is.

I disagree. Changing the oil is a poor analogy because you aren’t sure how much is left behind, so you verify with the dipstick.

On a transmission first fill you know exactly how much fluid is in the trans. Exactly Zero.

On an engine first fill at the factory I’m sure they just add the specified amount.

 

[thescreensavers]

I disagree. Changing the oil is a poor analogy because you aren’t sure how much is left behind, so you verify with the dipstick.

On a transmission first fill you know exactly how much fluid is in the trans. Exactly Zero.

On an engine first fill at the factory I’m sure they just add the specified amount.

We aren't at the factory, yes we know approximately how much should go into the transmission. Key word there "approximately"

You still always verify with the dipstick, The oil level procedure is the "dipstick" of our transmissions.

 

[gsi18867]

We aren't at the factory, yes we know approximately how much should go into the transmission. Key word there "approximately"

You still always verify with the dipstick, The oil level procedure is the "dipstick" of our transmissions.

For the damaged transmissions this thread has been trying to address, I don’t think the FSM fluid level check using temp is reliable. There are too many internal pressure/fluid loss points and foaming to be sure the fluid level is correct. Here and on the Lexus club pages, we’ve had people talk about their trans shops saying they were low on fluid after using the temp method. I know you are referring to a new setup and how much fluid to begin with versus the problem units this thread is discussing, but I think the temp method is still suspect. If the FSM says a brand new unit with an empty TC says 11.5 QTs, that’s what I’d put in there without a second thought. The Toyota engineer asshat that decided to remove the dipstick from these transmissions is probably responsible for more unit failures than the Toyota engineer asshat that decided to remove the secondary trans fluid cooler.