2004 LS430 has an issue with the transmission. Driving along and accelerating from a stop, it shudders at the top of second and third gear before it engages the next gear. Difficult to describe the issue in words. Smooth through first gear, smooth most of the way through second gear the top part of second gear before shifting the car shudders (pulses) then shifts to third gear. Third gear issues are a repeat of second gear. 4, 5, 6 are all smooth.

Saw a lot of issues with the jerking while shifting between gears in other posts. I believe this is different type of issue.

Things I have tried:

• 3 drain and fills using Valvoline one maxlife. (lets not make this post about the brand of fluid, there are a lot of people with opinions on either side of the issue) No Change
• ATF additive Lubegard 60902 Automatic Transmission Fluid Protectant. No change
• Lubegard 19610 Instant Shudder Fixx No change
• I did not have high hopes for the atf additives fixing the issue, thought I would try it because maybe just maybe the snake oil would work.. It did not.
• I did set the level of the transmission using the extremely complicated Toyota/Lexus temp, jumper, standpipe drain method during the drain and fill procedures.

Looking for any answers on where to turn to repair this. With the car being 19 years old I am not sure I am ready to spring for a transmission rebuild. I have no idea what that costs guessing 3-6000. Anyone had theirs rebuilt? A used transmission is $985-2000 plus shipping and who knows what you are going to get. Love the car so much, she spent her life in Ohio and is starting to rust. No ready to let her go just trying to get her running like a top.

 

I'd rather think it's caused by the ECU. It is the often case that the heat cycle damages the soldering points. If I were you, I'd simply check the inside of the ECU using a good magnifier and carefully see soldering points where bigger sized resistors are soldered. It is the often case that the heat cycle damages soldering points in case of a JDM Celsior. May be the same with a LS430.

Folloing resistors should be checked. R216,R217,R235,R236,R239,R241,R304,R305,R306,R307,R328,R329,R393,R738,R740,R752,R767,R769,R910,R912,R918,R919,R920,R921.
Especially resistors at this area.

 

Thanks for the reply. Where do I locate the ECU?

 

I am almost certain the torque converter is the suspect here.