Last post on Nov 22, 2009 at 3:38 PM
You are in the Lexus RX 300/330/350
What is this discussion about?
Lexus RX 350, Automotive News, SUV
#52 of 89 Re: transmission problem with brand new RX 350 [jym2009]
Jan 12, 2009 (3:44 pm)
Thanks for your comments.
It appeared that the particular car had a bad transmission. The service guy told me that there was no TSB on 2009. They had to contact the headquarters to dignose the problem and ordered a new transmission.
Anyhow, the Lexus dealer called me and told me that they would get a new car. Since Lexus stopped shipping 2009 models to dealers, they will probably get one from a different dealer. They seems to take good care of their customers.
#53 of 89 Re: transmission problem with brand new RX 350 [jym2009]
Jan 12, 2009 (5:17 pm)
Have you considered holding out for a 2010 RX350...??
Something about this SMELLS to high heaven.
The wording of your complaint is EXACTLY like that of thousands of RX330 & RX350 owners going back to 2003, 1-2 second downshift delay upon re-acceleration immediately following an unshift as a result of a lift-throttle event.
Under these circumstances I don't think I'd want to take a chance on ANY late production 2009 MY RX350. Lexus has been experimenting with various fixes/solutions for this problem since mid-2000. I wouldn't be surprised if the 2009 you had/have has another FAILED experiment/fix.
#54 of 89 Re: transmission problem with brand new RX 350 [jym2009]
Jan 14, 2009 (1:50 pm)
If they haven't figured out a fix for the 2010 RX350 you can make a sure bet that it still exists in the 2009 RX350.
Below quote is directly, word for word, from the 2010 RX350 factory manual set.
"The TCM determines the gear that is to be selected when the accelerator pedal is released (released completely) in accordance with the way the accelerator pedal is released (quickly or slowly) during deceleration. In this way, unnecessary upshifts are prevented during deceleration, matching the driver's intentions. In addition, unintended downshifts are prevented when accelerating the vehicle again, achieving smooth acceleration."
So, unless you can learn to abide by the above rules as to how you "manage" the accelerator pedal the 1-2 second downshift delay will remain a potential problem.
#55 of 89 Re: transmission problem with brand new RX 350 [wwest]
Jan 14, 2009 (1:54 pm)
"..Have you considered holding out for a 2010 RX350...??"
I take that suggestion BACK...!!
The 2010 RX350 (and the Toyota Venza) F/awd system was adopted from the Ford Escape/Mariner/Tribute design and is WORSE than the previous RX F/awd system by a WIDE measure.
Jan 14, 2009 (1:58 pm)
MSRP $46K with Navi
10k miles year, $800 out the door, $459/mo incl CT Tax
Thanks to everyone on here for sharing their experiences
#57 of 89 Re: transmission problem with brand new RX 350 [wwest]
Jan 14, 2009 (4:35 pm)
wwest can you elaborate on this Ford system and why it is worse?
#58 of 89 Re: transmission problem with brand new RX 350 [avery1]
Jan 15, 2009 (12:57 pm)
The new 2010 RX350 F/awd system, like the Ford Escape, uses direct drive from the transaxle output to the rear driveshaft. At the end of the rear driveshaft a "linear" electric clutch is used to modulate, modify, the level of engine torque, 0-50%, delivered to the rear diff'l.
The functionality of Braking, ABS, VSC, EBD, etc, depends on the rear driveline being INSTANTLY decoupled upon activation of any of these "features", and that is the Lexus procedure.
The way I read the information the only time(s) the rear drive line will be automatically "coupled" is under HARD acceleration or with front wheelspin/slip arising from too much engine torque being used for road surface conditions. There is an intimation that OAT, COLD OAT will play a part in the level of torque automatically delivered to the rear drive line.
If the clutch is fully locked, as it can be up to 18MPH under driver pushbutton control, the driveline and tires will be forced to "absorb" any stress due to high roadbed traction. If the clutch is only partially closed/engaged then the clutch itself will be forced to absorb any undue driveline stresses, stressing.
The Ford manual WARNS that in this circumstance, linear clutch overheating, the system may go to FULL engagement or be disabled altogether and advises the driver that should this happen the procedure to follow is to pull over long enough for the rear linear clutch to cool off.
Toyota and Lexus have been notoriously lax with this type of advice so I suspect we will not see this CAUTION note in any Toyota or Lexus owners manual until maybe 2013.
While I am NOT a strong fan of the current RX's F/awd it can be made more functional than the new one. The current model uses a fully OPEN center diff'l that will allocate the engine drive torque 50/50 F/R just as long as both "ends" have equal, roughly equal, traction with the road surface.
The "secret" to making use of the current system is to assure that F/R roadbed traction is ALWAYS roughly EQUAL. I do that by installing all four tire chains in times of need.
The only option with the new system would be to "wire" the rear clutch fully closed and disable one of the front drive halfshafts. You would then have a RWD vehicle, ultimately more safe than the new F/awd RX350.
I have been seriously considering the purchase of a Mercury Mariner hybrid (now with VSC) and should I do so it would go immediately into the shop for a REMCO front halfshaft modification and I would "hot-wire" the rear clutch fully closed.
RWD but with part-time 4WD capability via manually engaging the REMCO halfshaft coupling device.
#59 of 89 Re: transmission problem with brand new RX 350 [avery1]
Jan 15, 2009 (1:09 pm)
Assuming I keep my '01 F/awd RX300 until the transaxle (prematurely) fails, I will rebuild the transaxle but modify the drive system to R/awd. Now at ~75,000 miles.
Remove the front drive spider gear from the center diff'l, weld the rear drive spider gear to its side gear, install a VC from the '99 or '00 RX300. SOLID coupling to the rear driveshaft and only VC, Viscous Clutch, coupling to the front drive.
#60 of 89 Re: transmission problem with brand new RX 350 [wwest]
Jan 15, 2009 (1:52 pm)
This may be a silly question, but what is "OAT"?
#61 of 89 Re: transmission problem with brand new RX 350 [wwest]
Jan 15, 2009 (1:53 pm)
This may also be a silly question, or at least a lazy question, but does the new Venza have the same AWD system as the 2010 RX350?