Transmission Stutter

[RX in NC]

2004 RX330 AWD approaching 118,000 well-cared-for miles....

My wife has been complaining recently about her transmission stuttering briefly upon acceleration. She says that it happens sporadically, usually between 20 and 30 mph. The stutter lasts less than one second, but concerns her when she is pulling into traffic or merging lanes. I've not experienced the issue myself while driving the vehicle until last night when it occurred two separate times while I was behind the wheel on the way back from dinner. The situation occurred exactly as she has been describing it to me....

Because of the chronic faulty original transmission we experienced in her previous 2000 RX300 AWD, I've been changing the Type T-IV ATF every 30,000 miles via the drain-and-fill method since we purchased this RX330 in January 2007 at just over 30,000 miles. The current ATF in the transmission pan is clean bright red just as it should be, and is at the correct level....

Have any other RX330 owners out there experienced this issue? If so, what was your fix (if you found one)?

[jaswood]

2004 RX330 AWD approaching 118,000 well-cared-for miles....

My wife has been complaining recently about her transmission stuttering briefly upon acceleration. She says that it happens sporadically, usually between 20 and 30 mph. The stutter lasts less than one second, but concerns her when she is pulling into traffic or merging lanes. I've not experienced the issue myself while driving the vehicle until last night when it occurred two separate times while I was behind the wheel on the way back from dinner. The situation occurred exactly as she has been describing it to me....

Because of the chronic faulty original transmission we experienced in her previous 2000 RX300 AWD, I've been changing the Type T-IV ATF every 30,000 miles via the drain-and-fill method since we purchased this RX330 in January 2007 at just over 30,000 miles. The current ATF in the transmission pan is clean bright red just as it should be, and is at the correct level....

Have any other RX330 owners out there experienced this issue? If so, what was your fix (if you found one)?

"..happens sporadically.." "..pulling into traffic or merging lanes.."

Sounds seriously like the "SOP" 1-2 second downshift "re-acceleration" delay. DBW is used to delay the onset of rising engine torque in response to newly depressed gas pedal.

[lenore]

You might try disconnected the battery and turning headlights on then hooking back up and see if it resets the computer...Also have you change the filter inside the tranny....?

I assume this TSB was done a long time ago.

TSB TC005-03 (ECM calibration: shift feeling enhancement).

[RX in NC]

Thanks Tom. I'll do a battery disconnect and reconnect - perhaps a computer reset will indeed fix it....

I'll also look into that TSB you mentioned....

No, I've never changed the transmission filter. How difficult is it to access? I really don't want to drop the pan except as a last resort....

[lenore]

that is an old TSB, did you ever change the filter? Also on the Old RX there were two speed sensors on top, not sure about he RX330, maybe pull one and see if it has debris on the tip...Kind of like the speed sensors on ABS systems....They are usually on top and fairly easy to get at. Again sorry I dont have a RX330.

[lenore]

I know on the Old rx the filter was only accessable by dropping pan. let me see if yours has a filter. Thee is a filter according to Rock Auto site

http://www.rockauto.com/catalog/raframecatalog.php

Yep definetly, The lexus part site also shows one...similiar to old RX300.

http://www.mylexparts.com/partlocator/index.cfm?action=getJointLocator&siteid=214992&chapter=&sectionids=1,0&groupid=10057&subgroupid=20012&componentid=60556&make=20&model=RX%20330&year=2004&catalogid=1&displayCatalogid=0

[bainzey]

I know on the Old rx the filter was only accessable by dropping pan. let me see if yours has a filter. Thee is a filter according to Rock Auto site

http://www.rockauto.com/catalog/raframecatalog.php

Yep definetly, The lexus part site also shows one...similiar to old RX300.

http://www.mylexparts.com/partlocator/index.cfm?action=getJointLocator&siteid=214992&chapter=&sectionids=1,0&groupid=10057&subgroupid=20012&componentid=60556&make=20&model=RX%20330&year=2004&catalogid=1&displayCatalogid=0

Great link.

[RX in NC]

Update:

I removed the negative battery cable with the headlights turned on this past Saturday. Let the vehicle sit for a couple of hours like that, then reattached the battery cable. This action may indeed have reset the vehicle's computers. According to my wife, the transmission performed without a hitch on Monday and Tuesday. Time will tell if the improvement is temporary. Thanks for the suggestion, Tom....

And yes, in checking back through my records, TSB TC005-03 was performed by our local Lexus dealership in February 2007 not more than two weeks after we purchased the vehicle. I took it in at that time for several warranty items, one of them being a complaint from my wife about shifting harshness. I'm sure she was still gun-shy about transmission shifts then from her years of driving her previous 2000 RX300 crapmobile....

[lenore]

Hey, cross your fingers, maybe your reset worked. I would still, in the future consider the tranny filter.

[RX in NC]

The filter is on my list of things I may have to do to the vehicle. But I'm not willing to drop the pan to change it now. Perhaps at the next ATF drain-and-fill interval. Of course, if the situation gets worse I may have to bite the bullet and do it (especially if she keeps complaining about the shift quality and becomes afraid to pull out into ongoing traffic)....

[jaswood]

Update:

I removed the negative battery cable with the headlights turned on this past Saturday. Let the vehicle sit for a couple of hours like that, then reattached the battery cable. This action may indeed have reset the vehicle's computers. According to my wife, the transmission performed without a hitch on Monday and Tuesday. Time will tell if the improvement is temporary. Thanks for the suggestion, Tom....

And yes, in checking back through my records, TSB TC005-03 was performed by our local Lexus dealership in February 2007 not more than two weeks after we purchased the vehicle. I took it in at that time for several warranty items, one of them being a complaint from my wife about shifting harshness. I'm sure she was still gun-shy about transmission shifts then from her years of driving her previous 2000 RX300 crapmobile....

Within 100-200 miles of driving the engine/transaxle ECU control system will have restored the variable "learned" operational parameters that you reset to factory default via disconnecting the battery.

In about '08 Toyota/Lexus developed a technique, firmware revision, that attempted to alleviate many, most(?), instances of the 1-2 second re-acceleration downshift delay/hesitation. That may have been the TSB. The revision "watched" the driver's action with/on the gas pedal. A "fast" gas pedal lift, relatively, would result in the transaxle remaining in a lower gear on the assumption that the fast or rapid lift meant the driver's current intent was to slow using engine compression braking. A relatively slow lift of the gas pedal and the transaxle would upshift accordingly, assumption being that the driver now wished to enter cruise mode.

[jaswood]

Update:

I removed the negative battery cable with the headlights turned on this past Saturday. Let the vehicle sit for a couple of hours like that, then reattached the battery cable. This action may indeed have reset the vehicle's computers. According to my wife, the transmission performed without a hitch on Monday and Tuesday. Time will tell if the improvement is temporary. Thanks for the suggestion, Tom....

And yes, in checking back through my records, TSB TC005-03 was performed by our local Lexus dealership in February 2007 not more than two weeks after we purchased the vehicle. I took it in at that time for several warranty items, one of them being a complaint from my wife about shifting harshness. I'm sure she was still gun-shy about transmission shifts then from her years of driving her previous 2000 RX300 crapmobile....