wwest Posted February 29, 2008 Share Posted February 29, 2008 ab-o-li-tion 1. The act of doing away with or the state of being done away with; annulment. 2. Abolishment of slavery. Following statement taken from Lexus NCF, New Car Features, for the '99 RX300. 1. Direct Clutch Fluid Pressure Control Direct fluid pressure control using linear solenoids is adopted for fluid pressure control of B1 and C2 for engagement/release upon shifting between the first and second speeds and between the second and third speeds. The output pressures from linear solenoids SL1 and SL2 are led to B1 and C2 control valves for optimum control of each clutch pressure. As a result, the automatic transmission size is reduced by accumulator abolition and fine fluid pressure control not possible with clutch fluid pressure control using accumulators. "..the automatic transmission size is reduced by accumulator abolition..." Fluid pressure accumulators are often used to sustain/maintain fluid pressures for the brief periods it takes for the hydraulic pump speed to rise to the required flow level. Eliminating the accumulator was undoubtedly one of the methods used to make room for fitting more robust components into an otherwise light duty Camry transaxle that was now to be used to haul around a much bigger and heavier vehicle. Premature transaxle failures for '99 & '00 RX300's..... Prematurely burned ATF fluid for the '01 to '03 RX300 series... 1-2 second downshift delay/hesitation throughout the Toyota/Lexus FWD and F/AWD fleet due to DBW being used to delay the onset of engine torque until the gear type ATF pump could pump enough fluid with the engine at idle to bring the pressure back up to snuff.... Engine flare during 3-4 upshifts... All traceable to one simple engineering mistake made during the design phase for the RX300. Quote Link to comment Share on other sites More sharing options...
tmastres Posted March 3, 2008 Share Posted March 3, 2008 Premature transaxle failures for '99 & '00 RX300's.....Prematurely burned ATF fluid for the '01 to '03 RX300 series... So can we say that a softer driving style and not frequent fluid changes are a possible remedy for early RX trannys? Quote Link to comment Share on other sites More sharing options...
wwest Posted March 3, 2008 Author Share Posted March 3, 2008 Premature transaxle failures for '99 & '00 RX300's.....Prematurely burned ATF fluid for the '01 to '03 RX300 series... So can we say that a softer driving style and not frequent fluid changes are a possible remedy for early RX trannys? I'm not so sure the circumstances that lead to dowshifts for acceleratio quickly subsequent to an upshift are predictable enough that one could adapt your driving style. And I'm now more comfortable tha ever that my theory of a "quick fix" via increasing the ATF pump volume for the '01-'03 RXes is correct. The problem was/is that the higher pump volume results in extraordinary "localized" heating of the ATF for which the cooling arragement could be of little help. The DBW system obviously allowed them to go back to the low volume ATF pump but put owners in danger. Quote Link to comment Share on other sites More sharing options...
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