Replaced 2 transmissions(refurbished),solenoid valve box and swapped ecm module and car is still doing the same thing. Shifts hard into 2&3 gear Replacing the transmissions and having the same problem tells me it's not the tranny, BUT WHAT

 

Well, transmission is electronically controlled and I think, there is TCM, transmission control module.

 

I have the same issue now, and since I have a 2003 RX300 as a daily, I used that computer in my 2001 (with a rebuilt trans), to see if the shifting would be smoother, and that it was. The 2003 ECM works with this rebuilt tranny, because I updated all the electronics for shift controls, to the most modern replacement parts, and thus, I need either a 2003 or a way to update my 2001 ECM/TCM for their legacy technical bulletin to fix these shifting issues back when Lexus did a huge recall on the U140E transmission for mass failure due to the weld on the PINS for the planet sets. This update is very difficult to find, and many ECM update services will NOT consider this replacement update since it appears to be lost in the ether. I have tried contacting Lexus to get them to update it, but I could also just purchase an ECM for a 2003 model just as well, since swapping it for a test worked and fixed the shifting issue which is just about what you describe.

 

Make sure you are not chasing a "non-problem." When you say it shifts hard do you mean it waits to a higher RPM? As you may know the transmission is designed to do that when it is cold/not warmed up. After a few miles and everything is at running temp the shift point will move back to a lower RPM.

 

This is a very hard shift from 2nd to 3rd, and it doesnt change whether its cold or warmed up. I have replaced every solenoid and module, and got a new Valve body, that was supposed to be revised to post recall standards. This did not change the rough shift either. I then went to the engine and discovered the timing was off a tooth, so I fixed that and did the knocks and VVTs while I was at it, and cleaned out alot of sludge, and still, no changes to the shifting. This is all after I rebuilt the failed transmission that died from bad welds on the pins for the 1st/rev planet set, and I also changed all the clutches and the torque converter as well, since I know they are known for failure just as well, in early models of this U140e transmission. The last thing left is the TCM, and when I to reading up on it I saw that dealers were updating them after such rebuilds and replacements of the bad transmissions in an attempt to smoothen out shifting and prevent failure in these transmissions. So I sent in my Computer to a specialty place that updates such hardware, and in the end they determined the computer was bad, but, what really happened is they updated it to the older 2001 shift patterns, that no doubt were revised. When I inquired to them about this change, thats when they sent it back to me saying that they cannot figure out what the issue is with it, but, there is an issue none the less, so they called the whole thing bad.

Since I have a daily driver 2003 Lexus RX300 as well, I then swapped that computer out to my 2001 just to see how it could shift, and boom.. it finally shifted smoothly, despite of my doubts. That said, I can either purchase a 2003 ECM, or try to find a place that can update this old one to the right specs. It has been trouble even finding a dealership willing to look into this update I describe so, I fear if I do take it to get updated at a dealer, they will just update back to the old programming. That said, I just plan to buy a 2003 setup, and then change out the ignition lock, which is what I kinda wanted to avoid.