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Hestitation and Down Shifting

10 messages,  Last post on Feb 29, 2008 at 1:44 PM

You are in the Lexus RX 300/330/350 Forum.

What is this discussion about? Lexus RX 330, Lexus GX 470, SUV

Messages Page 2 of 2

#6 of 10 Hesitation by jim2244

Mar 08, 2007 (3:09 pm)

I have a 2005 RX330 with the same hesitation when accelerating at low speeds as does a friend. You might want to know the problem has made the February 2007 issue of Kiplinger's Personal Finance magazine.

#7 of 10 Re: Hesitation [jim2244] by la4mead

Mar 08, 2007 (4:03 pm)

Replying to: jim2244 (Mar 08, 2007 3:09 pm)
Another owner and myself are curious if the low-speed hesitation you are experiencing is related to tire slippage/VSC-Traction Control engagement when accelerating.
 
Can you give more details about yours and your friend's experience?
 
http://www.carspace.com/la4mead

#8 of 10 Re: Hesitation [la4mead] by jim2244

Mar 09, 2007 (12:05 pm)

Replying to: la4mead (Mar 08, 2007 4:03 pm)
I'm not sure if the hesitation I feel is due to slippage or some other problem, but I've only noticed it at low speeds, I think mostly between about 20 and 35.
 
I just asked my friend if he had a hesitation problem and he said yes and was going to have it looked at with his next scheduled maintenance, which is what I planned to do.
 
Also, I stopped to get gas this morning and asked a woman with an RX 330 at the pump next to me if she had noticed a hesitation problem. She said yes and that her husband said it was because the car was underpowered. I don't think that's it. I'm guessing its the transmission, but that's just a guess.
 
My primary concern is that it could be dangerous. If you need to get out of the way of an accident and an idiot, the hesitation could be a real problem.

#9 of 10 Re: Hesitation [jim2244] by 9119911

Jan 17, 2008 (9:38 pm)

Replying to: jim2244 (Mar 09, 2007 12:05 pm)
You may be interested in the fact that Toyota Avalon has this same problem. Toyota came out with a TSB that will correct the hesitation problem. If I get enough replies I will find the TSB number and post it and you can inform your service mgr.
As far as I know Lexus and Avalon transmissions are the same.
 
Cj

#10 of 10 Found it..!! by wwest

Feb 29, 2008 (1:44 pm)

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.

Messages Page 2 of 2

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