Originally Posted by insightbrewery
Heeyyy, Bay Area mechanic here (Santa Clara) that works on a lot of RX300/RX330. Weak point will be the transmission, that U140F is not great (have done two replacements so far), they didn't get most of it right until the U151 in the RX330. And those were daily drivers, you put yours through more than they ever did.
Install an auxiliary cooler and some sort of filter; I used to install Magnefines (still do, actually) but am trying a remote can-style oil filter this time. I would also consider installing a cold-weather bypass if you spend a lot of time in Tahoe. It won't do much in inland Cali weather, but will keep the trans from experiencing cold fluid-shock in snowy climes.
On a U140E/F, if you hear whining in 1st/2nd, it's on its way out (might be 5K, might be 50K depending on abuse). Synthetic fluid is a good idea; I run Valvoline MaxLife Dex/Merc in all the ones I service, shifts better, runs a bit cooler, and trans are still shifting fine when I recommend changes (every 25-30K on the U140, 40-50K on U151). In fact, the MaxLife works better than the T-IV I used to put in ES300 and RX300 where we were running 15K intervals to try and stave off trans failure...
Thanks for the post!
My vehicle had an early transmission failure within the first 3 years and the dealer replaced it, that was 15 years ago and about 150k miles ago. I heard they put larger valve bodies in the transmission as an improvement, not sure what I got.
My vehicle has a cooler, its stock, not sure which models got coolers stock? The AWDs? The ones with the towing package? Mine has the towing hitch. Did you mean install an addition one or one in place of the stock one?
I just dropped the pan about 2 months ago and changed the filter and put in new fluid. I didn't know about the other fluids so put in the Toyota IV. Transmission seems fine, no whine.
Next winter I will make about 9 weekend trips to Tahoe, Friday evening to Sunday afternoon. And maybe go for the week between Christmas and New Years.
The RX300 never had much power plus at its age and mileage, plus the loss at altitude, its a dog going up the steeper grades. I need to keep the rpms up to keep it in the max torque band. I will never get up donner pass taching 2,000 rpm. I turn overdrive off on using the switch on the shifter. I figure its better to let things rev a bit then lug the engine and transmission. I would say I usually don't have O/D off for more than 5 minutes or so. I turn O/D off only when I need to climb.