#Transmission Failure or Issues
https://www.clublexus.com/forums/gx-...e-zerks-2.html
I also regreased all the driveshaft zerks the moment I bought the GX last year.
The issue is definitely the transmission. It doesn't seem to know what gear it wants to be in and suddenly shifts from 2nd to 1st, and it lurches forward. I really want to know if others have this issue.
Last edited by zsnethen; Aug 11, 2023 at 01:48 PM.
One thing I didn't do was check level before my fluid change since I was changing it out anyway. I wish I had. That would be a simple first test to see if low (or high) fluid level may be causing issue. So I don't know if the fluid level was cause of rumble strip issue or old fluid.
This was my gizmo to pin out thermostat, cap line, and circulate fluid out 2 quarts at time by running engine 30-60 seconds each time. Do at your own risk. I was pretty familiar with procedure from doing it on Volvos. Otherwise I might not have risked it.
One thing I didn't do was check level before my fluid change since I was changing it out anyway. I wish I had. That would be a simple first test to see if low (or high) fluid level may be causing issue. So I don't know if the fluid level was cause of rumble strip issue or old fluid.
This was my gizmo to pin out thermostat, cap line, and circulate fluid out 2 quarts at time by running engine 30-60 seconds each time. Do at your own risk. I was pretty familiar with procedure from doing it on Volvos. Otherwise I might not have risked it.
I'm convinced it is a result of the transmission attempting to upshift at the earliest possible point, which often means it is in too high a gear for the conditions. The hesitation occurs when you need to accelerate, but the transmission has to downshift first. After that happens and the vehicle surges forward, the transmission upshifts and the cycle repeats ... hesitate, downshift, surge, upshift ... repeat forever!
Pull the shift lever to the left, which will put the transmission in the 'S' mode with the upshifts limited to 4th gear. If your speed drops low enough, such as maneuvering in a parking lot while searching for a parking space, pull back to limit to 3rd or again to limit to 2nd gear ... 1st gear is too jerky for anything other than hill climbing or steep descents.
Once you get back on the road, push the shift lever to the right and let it shift for itself. Even better ... leave it in 'S' and push forward to '6'. You may notice the shift points advance slightly, i.e., the engine revs further before it shifts. Even better, pulling back on the shift lever in 'S' keeps the shifts sequential, e.g., 6, 5, 4, 3 etc. rather than an non-sequential 6 to 4 "double-downshift" when you go 'left' from 'D' to 'S'.
You will pay a small price in mileage for using the 'S' mode, but good gas mileage isn't why we bought the GX 460, right?
Regards,
SaniDel
P.S. As Craig said, this problem could also be caused by low-octane fuel, but I use only 93 octane in sea-level Delaware as you in Florida. The problem is the transmission ... low-octane fuel could make it worse, but using the transmission as suggested solves the problem ... with the proper fuel.
at least you can remedy the pi$$ poor throttle mapping with a peddle commander. Unfortunately we are SOL with the transmission tuning.
We need someone to develop a sophisticated tune that recalibrates the transmission tuning/shift points and throttle mapping. This would really awaken the GX460’s lumbering V8 power train. I’d buy into this.
at least you can remedy the pi$$ poor throttle mapping with a peddle commander. Unfortunately we are SOL with the transmission tuning.
We need someone to develop a sophisticated tune that recalibrates the transmission tuning/shift points and throttle mapping. This would really awaken the GX460’s lumbering V8 power train. I’d buy into this.
I have a 2011 GX 460. It is paid off and I would like to keep it for a few more years. It has a 137k miles on it. I replaced some parts in the cooling system within the last year, but other than that it is in good shape.
## The Problem ##
The day after returning from a long road trip (3 hrs each way) I started the car and some lights on the dash were illuminated. Using a code reader I saw that it was P2714 - Pressure Control Solenoid D Performance / Stuckk Off. I did a little research and that part is inside the transmission case. That's not a job I would normally take on myself. I've never opened a transmission before. I took it to the dealership to hear what they had to say.
They said that they found issues with "some" of the solenoids in the transmission. I asked for clarification if that meant more than one and if they actually ran the test to exercise the part or if they just read the code like I did. I haven't hear back on that yet.
## Initial Quote from my Local Dealership ##
The quote they gave me was for a little under $8,000 to replace the transmission. They said that they don't open or rebuild transmissions. Only replace. They said that they could, probably, reuse "the core", but I'm not sure what that means.
## My Capabilities ##
I have taken an engine apart, but that was 30 years ago and I was in an auto hobby shop. I don't have a cherry picker in my home garage. I do have a rolling jack, stands, wheel chalks, and any size wrench or specialty screw heads that I might encounter. In the past 5 years, on this car, I've done the work to:
- Replace brakes/rotors (I left the calipers open so that I didn't have to bleed the break line)
- Replaced the secondary air injection pump and both switching valves.
## What Are My Options ##
Would you help me enumerate my options or share any insights or recommendations you might have?
- Is replacing one solenoid easier than I think it would be? I have the time. Is it worth doing myself?
- Should I find a shop that will open the transmission to just replace that solenoid? What should I look for to find a competent shop?
- What happens if I do nothing? What if I clear the code and wait to see what happens? Any chance this was a one-off incident and the part will, potentially, work just fine for a while longer?
- I have the money. Given that I'd like to keep the car for a few more years, is it worth investing in having a professional do the work?
- That much money would be a nice down payment on a new car or a few years worth of monthly payments. Should I abandon my hope of keeping the car for a few more years?
What would you do in my situation?
Thanks!
Celebrating Lexus & Toyota from Around the Globe
- P0761
- P2714
Certainly, the intermittently failing parts should be replaced. The whole transmission? I think that is dubious.
Any thoughts?
My opinion is Lexus should have put AT coolers on all 460s and stressed at least 60K AT fluid maintenance intervals for all vehicles and 30K for those that tow.
Would I damage anything outside of the transmission if I delayed replacing the transmission until those solenoids fail again or fail consistently? If I'm going to replace the transmission anyway, what is the rush? My understanding is that the worst thing that will happen is, when the solenoids do fail, the transmission would first be choppy as it changed gears but eventually would tear itself up. Is that correct? If I let it get to closer to that point would I be replacing anything that I am not considering replacing now?
I was just about to ask about that. The dealership said that I should never change the transmission fluid. Something about it was designed to stay sealed with the initial fluid it has or something like that. Does that sound right to y'all?
So, no, I have never had the fluid changed or transmission flushed on this car.
Last edited by GuyHoozdis; Sep 12, 2023 at 12:54 PM. Reason: typo
I was just about to ask about that. The dealership said that I should never change the transmission fluid. Something about it was designed to stay sealed with the initial fluid it has or something like that. Does that sound right to y'all?
So, no, I have never had the fluid changed or transmission flushed on this car.










