For a year or so now when the transmission is in too high of a gear and I accelerate, I will get lagging vibrations. Kind of like you get when shifting a manual transmission into 5th gear too soon. Only now its starting to get noticeably worse and will mostly happen 40-45mph but will also happen sometimes at 25 and 35. I know it's not the tires, as I just had a new set put on.
Seems like when I searched this down before, I cannot find the post on here for the life of me, and I want to say I saw a solution of resetting the transmission. But I am unable to find any info on that either, so I figure I'll just get on here and ask if anyone knows what is going on.

Happy to answer any questions you might have to diagnose.

Thanks. )
2010 rx350
150k miles.
normal maintenance done and oil changes every 7500'ish.
one transmission fluid change around the 100k mark.

 

I suspect that one or more of your engine mounts and/or transmission mounts are worn out and need to be replaced. Any competent independent repair shop can inspect your RX for this issue and replace them if needed. Or they may find another fault for the issue.

 

Thx for the info. I started pricing mounts and such online and ended up going..... Nevermind. Long story short. I found my tranny filter and gasket in the shed. Which means I never changed the fluid years ago. Probably because of the 'sealed unit' issue. Anywho. Going to start with that I think. If that doesn't help to solve the issue then I will buy some decent jack stands to get this thing up in the air and check the mounts.

 

These Aisin transmissions are mediocre at best. Doing a three-step series of ATF drain-and-fills every 60,000 miles or so offers a much better chance of keeping them alive. Why three steps? Because only 2.25 to 2.5 quarts of ATF drains out each time. Three successive drain-and-fills done after 40 or so miles of driving each time will wind up replacing 85% to 90% of the ATF in the system. That is typically good enough.

 

This is the thread that discusses how to perform a transmission fluid drain and fill. It is very long. The transmission is sensitive to fluid level, so measure carefully. I hope a few drain and fills help.
https://www.clublexus.com/forums/rx-...threads-4.html

You do not have to use Toyota WS. I have used both MAG ONE low viscosity full synthetic multi vehicle ATF made by Warner, who makes most of the private label oil in the US. I think it made the trans shift faster and smoother, or it was just new fluid.

I used Idemitsu low viscosity ATF (in my Sienna - same transmission) which is designated as a direct substitute for Toyota WS. According to the folks at Bob is the oil guy forum they have talked to the Idemitsu folks and it is full synthetic as indicated by its specs although they did not label it that on the bottle. Must be a Japanese thing. Anyway, you can get both at Amazon.
https://www.idemitsulubricants.com/p...tf-type-tls-lv

Many have also used Valvoline MaxLife in the red bottle.

 

Does the transmission downshift properly? At 25-35 mph, the transmission should shift to 2nd or 3rd, depending on rpm. If not, you may need a new downshift solenoid. Also check the ‘wishbone’ engine mount. It’s on top of the engine. You should be able to see if the rubber insert is broken.

 

Yes. Downshifts just fine. Best way to describe it is it shifts into fourth when it should still be in 3rd for a few more rpms. Then when i give it a touch of gas it vibrates. More gas and it downshifts. The vibration lasts for two or three secs.
Got stuff rolling in through the mail. Everything should be here for me to get to work on it mid week.

 

Ok. Finally got underneath of this thing and did some work on it. Man oh man does this tranny fluid flush make a difference when driving. It's like everything has tightened up. Quicker shifts with more torque available on takeoff and just about any time I press on the accelerator. It also seems to shift at higher rpms now.

Unfortunately this did not fix my issue. All four wheels off the ground. Letting the wheels spin at idle. Then pressing on the brakes.... There is quite a lot of movement in the motor. Pretty sure it's the mount behind the oil pan. But it was dark. And I was in a hurry to go sit on the couch. So took a few vids and need to look them over to make sure. Thanks for all the help y'all.

 

You mentioned resetting the transmission. I believe that is called a “reflash”, ie flashing the transmission. That might help but I am not familiar with the procedure.
https://www.mytransmissionexperts.co...t-time-to-fix/

 

How and where can I do a reflash? Im getting the transmission shudder. Location Toronto Canada

 

Start with a fluid service, if shudder is present. There is a reset procedure for our adaptive transmissions, which I've only had done at the dealer. I don't think the reset would contribute to a shudder resolution, but I could be wrong.

 

Rule out simple things like fluid level and transmission + motor mounts before thinking of reflash.

Salim

 

Irrelevant to the RX. There is no software update for it.

 

Long term update. I now have zero vibration/shudder lag after letting the new tranny fluid do its thing. As said a couple days after doing the flush, things were a lot better. Within a couple of weeks all vibrations were gone. I still have not replaced the motor mount that looked bad. I have to assume it wasn't since I no longer have any issues. Thanks again for the help and advice.

To sum up. I changed the filter and ran 8 qts of Valvoline MaxLife tranny fluid through the torque converter. All is well. There is a noticeable increase in power due to the transmission shifting crisper and sharper. Not saying it lacked power before. It's just noticeably better. One day soon I will do another 8 qts as icing on the cake.

edit: If a Mod would be kind enough to add [FIXED] to the title to help others with same issue... that would be fantastic.