Hello all!
I purchased a 2008 RX350 a few days ago. 153k miles and literally grandma owned. I have all the service records. PO did a fantastic job. The interior is an A+, exterior shows it's age but solid. The undercarriage is in good shape for a Maine vehicle.
Mechanically it is almost flawless. Once warmed up, there is a shudder between 1500 and 2000 rpm. I have heard everything from bad gas, coils and plugs to drive shaft being the issue. I spoke with the reputable shop that has worked on it for the last 90k miles and they suggested a trans flush with some anti-shudder and that might solve it. If I drive it in 'manual mode' the problem is gone.
I have searched this fine forum for a few days and did not come across anything that fits this issue. I love this thing already and don't want to part with it but can't justify a new/refurbished transmission.
Any assistance would be appreciated.

Thank you

 

I wouldn't flush. I would do a few drain & fills then drop pan, change tranny filter and clean magnets / pan. The trans relies on the MAF for shifting so exhaust leaks or clogged air filter, throttle body, etc can affect shift quality as well.

 

 

Good troubleshooting. A lot of us 1st gen Highlander owners have had great results from doing drain and fills + filter and then some Lubegard red (Seems to work best on these transmissions). No shutters in my case but I had some pretty good shift flares and overall rough shifting until I did that filter. How does the fluid look? Mine wasn't burnt or black, but was definitely brown and worn. Surprisingly 210k+ miles and original fluid according to the PO! Transmission mount was also completely exploded which led to some rough shifts into drive.

As for the driveshaft, on my friend's RAV4 there was a very annoying shutter that was speed dependent in the 45-50 mph range under load only. When I took it off the car, the u-joints were completely exploded and were super loose. My car didn't see the best results after cleaning all the crud up, until I disconnected the battery allowing the ECU to re-adjust.

 

Fluid is pretty clean. LIke 85-90%. The rest of the transmissions work is great and again; it doesn't do it in manual mode. 210k on original fluid..wow.

 

I too had a shudder a couple years ago - car had approx 165k on it then. It only occurred under load, and around the 1500-2000 range (notably in 1st and 2nd gear). Checked the driveshaft and there was a bunch of play at the u-joints. I decided to just buy a cheap whole driveshaft online from carparts.com. OEM would naturally be better but the one I got was approx $350 versus $1,100 so was willing to take the chance (and it's held up just fine so far). Replacing it was quite straightforward.

 

Interesting. I appreciate the insight. I'm gonna try to get it on a lift tomorrow and see if there is any play in the u joints. Wouldn't it still shudder when I shift manually though if it was the driveshaft?

 

Torque converter shudder & or a shift solinoid, caused by fluid contaminated fluid....Good to pull the pan & clean the 2 magnets, swapout the filter for a Wix, add a gallon oftrans fluid.....See how it shifts then possibly add ''Instant shutter fix'' by Lubeguard.....

 

Wasn't there an update to the trans software at one point (basically changing shift points)? Or was that the RX330 only?

I did that on my RX330 way back. Paid 100$ for the flash from the dealer. Fixed it entirely...

 

Good news so far! Full flush, filter change and some shudder guard appears to have solved the issue. I have only put on about 50 miles since but driving like a champ!
Thanks to all for the help!