Occasional abrupt trans shift - ClubLexus - Lexus Forum Discussion

Notices
LS - 3rd Gen (2001-2006) Discussion topics related to the flagship Lexus LS430

Occasional abrupt trans shift

Reply

 
 
 
Old 04-07-17, 02:57 PM
  #1  
Bocatrip
Lexus Champion
Thread Starter
 
Join Date: May 2006
Location: Fl
Posts: 2,431
Thanked 41 Times in 40 Posts
Default Occasional abrupt trans shift

For 7 years and now at 128,600 miles my car had always shifted flawlessly. The car has always been serviced at Lexus by the previous owner. The fluid is very clean (red) and does not smell burnt. I have never changed the fluid since my purchase and have put 30,000 miles on the car. I do pretty much 100% city driving and very occasionally go on the highway. Every now and then (probably when warming up) the car might have an abrubt shift going into an upper gear. Never has it happened dropping to a lower gear. Is there any resetting of the ECU that might help instead of changing the transmission fluid? Again, it does not happen very often and the trans does not slip. Thanks again for any feedback.
Bocatrip is offline  
Reply With Quote
Old 04-07-17, 03:29 PM
  #2  
JffGRY706
Lead Lap
 
JffGRY706's Avatar
 
Join Date: Sep 2014
Location: Texas
Posts: 510
Thanks: 0
Thanked 16 Times in 16 Posts
Default

my car with the 6 speed transmission will not shift into overdrive until the temp reaches between the C and the 1st mark. I am usually going 75 mph before this point is reached and the shift into overdrive is noticeable to me. It was worse before I did a couple drain and fills 30,000 miles ago and is beginning to become more apparent now. I am wondering if the 5 speed also has this built in to its transmission. just wondering
JffGRY706 is online now  
Reply With Quote
Old 04-07-17, 03:44 PM
  #3  
tallcaguy
Lexus Test Driver
 
tallcaguy's Avatar
 
Join Date: Oct 2010
Location: CA
Posts: 1,173
Thanked 42 Times in 42 Posts
Default

If you have an 01-03, shifting should be invisible. With 04-06 shifting should be seamless. Besides the occasional abrupt upshift, does it generally shift smoothly? City driving (rather than freeway miles) generally means more wear and tear on the car.

Both my Lex mechanic (01 430) and tire shop guy (Honda) do drain& fills. With my 04 (at 102), the shifts were noticeable. I did 2 (drove 1k between each) and the car now shifts seamlessly.
tallcaguy is offline  
Reply With Quote
Old 04-07-17, 04:16 PM
  #4  
Bocatrip
Lexus Champion
Thread Starter
 
Join Date: May 2006
Location: Fl
Posts: 2,431
Thanked 41 Times in 40 Posts
Default

[QUOTE=tallcaguy;9828554]If you have an 01-03, shifting should be invisible. With 04-06 shifting should be seamless. Besides the occasional abrupt upshift, does it generally shift smoothly? City driving (rather than freeway miles) generally means more wear and tear on the car.

Both my Lex mechanic (01 430) and tire shop guy (Honda) do drain& fills. With my 04 (at 102), the shifts were noticeable. I did 2 (drove 1k between each) and the car now shifts seamlessly.[/QUOTE)

I would say that the majority of the time my car shifts like butter and I don't even notice the shifts. It generally is noticeable when warming up and driving very slowly. I was just thinking that I do so much city driving that a possible ECU reset (if there is even such an option) might help. Not thinking of doing a drain and refill at this time. I checked my fluid level numerous times today and it is just about on the full mark after driving 30 minutes. Fluid level and condition of fluid is not an issue.
Bocatrip is offline  
Reply With Quote
Old 04-07-17, 05:59 PM
  #5  
airchomper
Pole Position
 
Join Date: Dec 2013
Location: Minnesota
Posts: 277
Thanks: 0
Thanked 5 Times in 5 Posts
Default

Originally Posted by JffGRY706 View Post
my car with the 6 speed transmission will not shift into overdrive until the temp reaches between the C and the 1st mark. I am usually going 75 mph before this point is reached and the shift into overdrive is noticeable to me. It was worse before I did a couple drain and fills 30,000 miles ago and is beginning to become more apparent now. I am wondering if the 5 speed also has this built in to its transmission. just wondering
It does actually. My car (01) doesn't fully lockup / shift into overdrive (idk which one) until the temp needle hits the first mark above C. It's not very noticeable, but I try to drive slower (50-55 mph) until it locks up and the smoothness might be a function of speed. I've always meant to pull out my ODB reader and figure out what the temperature threshold is, my suspicion is that the transmission locks up at the same time the thermostat opens.

When warm, my car sometimes shifts abruptly into 5th gear if I'm going downhill at ~40 mph and have a very light or no throttle opening.
airchomper is offline  
Reply With Quote
Old 04-08-17, 10:00 AM
  #6  
tallcaguy
Lexus Test Driver
 
tallcaguy's Avatar
 
Join Date: Oct 2010
Location: CA
Posts: 1,173
Thanked 42 Times in 42 Posts
Default

[QUOTE=Bocatrip;9828575]
Originally Posted by tallcaguy View Post
If you have an 01-03, shifting should be invisible. With 04-06 shifting should be seamless. Besides the occasional abrupt upshift, does it generally shift smoothly? City driving (rather than freeway miles) generally means more wear and tear on the car.

Both my Lex mechanic (01 430) and tire shop guy (Honda) do drain& fills. With my 04 (at 102), the shifts were noticeable. I did 2 (drove 1k between each) and the car now shifts seamlessly.[/QUOTE)

I would say that the majority of the time my car shifts like butter and I don't even notice the shifts. It generally is noticeable when warming up and driving very slowly. I was just thinking that I do so much city driving that a possible ECU reset (if there is even such an option) might help. Not thinking of doing a drain and refill at this time. I checked my fluid level numerous times today and it is just about on the full mark after driving 30 minutes. Fluid level and condition of fluid is not an issue.
Per Airchomper, sounds like it's a warm up issue. Doesn't sound like you have anything to worry about.
tallcaguy is offline  
Reply With Quote
Old 04-08-17, 03:34 PM
  #7  
jpv7774
Lead Lap
 
jpv7774's Avatar
 
Join Date: Sep 2014
Location: VA
Posts: 698
Thanks: 0
Thanked 7 Times in 4 Posts
Default

There is a commonly discussed lurching shift at low speeds as the car glides into a slow turn then you put your foot on the pedal to slowly accelerate it will rev then shift. I had the software update at Lexus Dealer done to resolve this issue.
jpv7774 is offline  
Reply With Quote
 
 
 


Thread Tools
Search this Thread
Quick Reply: Occasional abrupt trans shift


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: