Bought this car w/ 125k miles on it and expected to put a little money in it. Sis replace power steering hose. Drove it quite a bit, then when going 70 mph at the top of a hill I heard “clunk!” …it was still running, so got to where I was going…let it cool down…felt HOT–can’t remember if light(s) or gauge high though…when I started it back up and drove a bit, the “AT Oil Tepm” light came on…I quickly went to a Jiffy ube and asked if I should change the AT fluid…he said it “might” work…well…it didn’t, and the tranny failed…Had it towed to a long-time trusted place and had a new transmission put in for $4600 PLUS $2000 more related repairs to make sure it wuld be in great shape to give my daughter…I bought ANOTHER USED RX (2007) nd was loving that…During the time she drove the 2005 after tranny work, it began overheating…and new radiator and other work done…then she wantted a different car…so I took the 2005 back over and sold the 2007 RX350–which never had ANY problem, but much lower miles…So…I kEEP having the overheating thing-- After bweing on the highway for 30 min+, and then being in idle…like stop and go or stoplights…then going 75…I get the “AT Oil Temp” light and the tranny goes out just as before–ONLY 2 YEARS BEFORE…I called the tranny place and he sent a towas it was undr FULL WARRANTY…They rebuilt it and when i picked it up…it had a noticeable “shudder” when accelerating from low speed or stop…Guy saidto bring it back around 200miles to check everything…Well…I wa tryi8ng to do that…started overheating after being on the highway…and TRANNY FAILED AGAIN! It is back at the shop…but I am soooo worried…and broke too…Does anyone know what the problem might be? At this very reliable place, they are saying defective parts…anddI cheecked about what all they do for rebuilt transmission…they completely flush the radiator and all transmission cooler lines…This place has done many Lexuses, including RXs…
If anyone has tips for this rebuild and of what to check and replace, i would be so grateful! Thanks. Stressed in CO
It’s obvious what the problem is . . .
The “long-time trusted place” never properly diagnosed the root cause, and if your diagnosis is improper and/or incomplete, then any repairs are a roll of the dice
Based on your paragraph, that shop has proven they should NEVER have worked on it
Why on earth did you sell the 2007 RX350 which never gave you any problems, while keeping the 2005 RX330 problem child . . . seems like a big mistake to me
If anything, you should have kept the RX350 and bailed on this turkey 
An idea . . . bring the car to a reputable independent transmission shop and ask for a diagnosis. Tell them everything that has happened, including the fact the first shop attempted multiple times to repair the vehicle. And when you get the estimate, contact the first shop and tell them they still owe you a proper repair, yet you don’t trust them to do it, and would they be willing to foot the bill for the second shop
Yeah, this is probably not going to end well . . .
Are the cooling fans kicking in on this car? Radiator ever been replaced? Also the thermostat? First thing I would have checked with the overheating would be if the cooling fans were coming on. If they are not and the transmission is cooled by the radiator you are just cooking those transmissions
Have you ever had a Lexus? Just curious, because I was looking for answers that actually pertain to the current situation…
I had a car payment on the RX330 when the transmission went out…can’t just make that “go away”…and was working as a special ed teacher 70 hours /wk at a treatment ctr for kids…I tried to trade it to a Lexus dealership, and was proposed the 07 RX350…soooo…had the engine compression checked on the RX330 and decided to proceed with a repair because it is a good car…and I wanted it to be in great condition because I gave it to my daughter for high school graduation because it is a very safe car… fast-forward…I had a sudden heart problem and had to have a surgery…then deplete my savings to go on state insurance plan and had to take a low-paying teaching assistant job…it even qualified for food stamps, but was a great job…so…I could no longer afford $650/mo. in car payments, and although I was never late on a payment, I turned the RX350 into the credit union…and took the RX330 back over and my girl got another car…BECAUSE I had put the $$ in this, it seemed the better car to keep for 2 years…OK…
And Best Western Transmission in Colo Spgs has been in business since the 70s! They are fully standing behind the work…Now I will talk with the person who seems to understand the real issue I can do something about…thanks for your…errrrrr…opinion!
Hey, Kinsha–Thanks for your reply…To my knowledge, the fans are working…and I had put a new radiator, water pump and hoses on this a YEAR AGO…yeah…lots of $$ put i this car by myself and brother when he was working at a dealership (chevy) as a service writer…and trying to help his niece when she had the car…
I’mm sure all fans will be checked…it seems to overheat when coming off the highway and then in stop and go…I have inquired about transmission coolers and if there is a “fan clutch” on these…Would you (or anyone) know if there is? Also—air conditioning started running hot and cold…I know that means something…bad…and the coolant did NOT need to be replaced…:- ( ANY help appreciated, and I am going to consult Lexus of C Spgs too…even ifIhave to pay to have it looked over…
I recieved your email. All your symptoms to me are atributed to one or more of the cooling fans not operating. You asked if the car has a fan clutch - the answer is no. All the cooling is done with electrically operated fans. Usually one that comes on when then car reaches a certain temp. via a sensor to keep it from overheating. The other usually comes on when the AC is turned on. So in other words when the AC is switched on both fans should be running continuously until it is turned off ( and still run a little after it is switched off till the car reaches a cooled down temp. ) It is easy to see if both fan motors are operating to rule them out. Simply turn the air on. If one or both do not turn on then more than likely you need new fan motors. The other is start the car and see if the fan kicks on as the car comes up to temp. If it does not you need a new temp. sensor usually they are screwed into the radiator or by the thermostat. I am not sure if the car came from the factory with an external transmission cooler. Many automatic cars transmission fluid runs through a cooler in the radiator. Which would be why your transmission is over heating.