tomr51

have you checked and topped up the ATF as described above? Did it fix the problem.?

stanleybg

Yes i put the car on flat surface. I make the transmission oil at 80 celsius and checked it was a little low like 200 grams. Added , then drived again and checked. All okey. But the car still shudders hard at low rpm when lockup occurs. Above 60mph its not doing it. When i removed the tranny oil pan there was not any metal particles so i guess it's not transmission itself. May be torque converter as i read Lexus changed the design of the damper plates with the springs with better one. Or sticky lockup valve or pressure valve. I have also upshift problem with light pressed gas pedal from 4th-5th only. All other shifts are nice. May be next step is to remove valve body open the solenoids and clean them and their bushings.

tomr51

keep us updated on your progress

stanleybg

Sure this weekend i hope to have time to check valvebody and solenoids.

stanleybg

I ordered this -LUBEGARD HIGHLY FRICTION MODIFIED ATF SUPPLEMENT 61910
I will try to modify the friction of the Amsoil so to stop this shudder. I tryed lubeguard instant shudder fix and worked for 1-3 days. Now will try this one. May be the oil is too thin. Before i changed the oil with Amsoil there was no problem. I also added 4 botles instant shudder fix , and Lubeguard ATF protectant. No this is the last addittive that i will try and if this does not help i will start opening the tranny.

tomr51

has anyone else used amsoil? I previously had a Soarer, (SC400) and the gearbox would only function with the toyota 4 transmission fluid. I have drained the transmission pan on the RX350 and refilled with Toyota WS as specified.

The toyota transmissions are very sensitive to both fluid type and also the level. I would only use the Toyota fluid specified. Stanley you say before changing the ATF it worked perfectly. Maybe drain and refill with Toyota WS.

stanleybg

Not perfectly i had this 4th-5th gear bump with gas pedal released or lightly pressed , but there was no shudder. My old RX300 2001 year works perfectly with Amsoil , actuallty it is using Toyota T-IV fluid wich is different. I think this lubeguard will fix it. As it adds a lot of friction to the oil. If it wont help i will flush with toyota WS oil. Before that i read a lot people using Amsoil instead of toyota fluid and are very satisfied. May be my transmission loosed lock up power and torque converter power a little and its on the edge to work good.
As soon the additive arrives i will test it two days as it needs to soack into the clutches and will write you back. Last step is to clean solenoids they can became clogged if driven with burned fluid. The old one was not burned at all. But it could be changed i dont know.

stanleybg

I ordered lubegard platinum , and lubegard Highly Friction Modified Transmission ATF Fluid Supplement. Also i ordered Valvoline ATF that many toyota users use and have great results. Firs i will try the platinum , i will drive 2 days to see is there any difference. If not then i will try lubegard Highly Friction Modified Transmission ATF Fluid Supplement If that dont help i will flush all ATF and put Valvoline. Then if no good results will add Lubeguard platinum. If this dont help i will change torque converter and clean valvebody.Strange thing is that Valvoline is covering Toyota T-IV and Toyota WS same time. But on many toyota forums they have great results and use it with years of driving. Also many tranny shops put it and say it works perfect with years.

stanleybg

Before 2 hours i drive the car 30 minutes to get the oil normal temperature. I have put the lubegard platinum and drived again 30 minutes. As before the first impresion i very good , the car shudders on lockup only uphil and like 50-60% less. But this cant be taken like evidence ,because the weather now i cold , not like when i shudders like crazy on lockup. One think i know for sure the 4th to 5th only bumps on hot oil and not always. I am pretty sure that the oil is too thin for my tranny. Because its 130 000miles car and there is towing hitch the prevoius owner was towing for sure.I am waiting the other lubegard addon to try to tick the oil to level of toyota T-IV. Its possible that the platinum that i have added now with the time to became more and more working , because it needs to soack in clutches inside the tranny. Instructions says max results after overnight.Transmission is very good pulling , not vibrations no thinking its going hard and smooth. Also i beleive that hte 4th to 5th upshift bump can be caused because of this thin oil. May be when adapting with it , and 4th to 5th slips more than normal and it wont to reduce this slip with hard shift. I dont wanna open this tranny because just of this. May be tommorow if its not okey after two days i can flush with valvoline ATF. As i read my valvoline oil is for Europe and its not named max life. But its fully synthetic. And it supports toyota WS and Toyota T-IV. May be to support both it is thicker. Something in the middle. On high RMS i dont have shudder abowe 2000rmp i mean. May be this thin oil is not doing good pressure on low rpms.
Will keep update

tomr51

why do you not use the toyota WS that LEXUS specifies. You have spent a lot of time and money on looking for a solution, but not tried the specified ATF.

stanleybg

Because Toyota WS is mineral oil. Its quality its not good at all. I change in all my cars oils with syntetic and they dont leak , and dont cause any oil problems.

tomr51

ok, i did not know toyota WS was mineral oil. I replaced the diff with a synthetic oil, but used toyota WS again in the gear box

stanleybg

One more thing i am checking fluid level on transmission 80 degrees celsius (176F) and the mark on the dipstick at max hot line. That is correct ?

tomr51

check level at normal operating temp should be on max full mark.

i researched on the net re Toyota WS and found this

https://www.tacomaworld.com/threads/....331521/page-5

stanleybg

I read all the forums and this one. I dont beleive it's toyota OEM fluid is ****. Its not syntetic and need changing more often. Also i think for heavyduty its not good. When i drive my car i drive it hard. This is why i want the best fluids. I will try to put more fluid in it than normal. Because when i checked the level before i start changing the fluid it was way more than normal on hot engine. Like more tha 1 liter.