Transmission Shift Solenoids?

[jmp235]

I have been all over this forum since picking up a 99 RX300 the other day. Car has 139k on it. Awesome info in here! Mine has the dreaded 2-3 shift issue, the kicker is, guy I got it from just had the transmission replaced with a 50k mile JDM because of said issue. Got the car back and it was still doing the same thing with the new trans in it. Now some research I have done on the JDM transmissions is that they say you have to use the solenoids from the stock trans as they do not come with them, maybe I read wrong. That being said could it be the solenoids themselves. Also I see that there is a “shift improvement kit” anyone have experience with them and do you think I am on to something with the solenoids? Thank you 

[RX400h]

Quote

The 2-3 shift issue you’re experiencing with your 1999 Lexus RX300 is indeed a common problem. This issue is often caused by a design flaw in the valve body, which was corrected in later models.

Regarding the JDM (Japanese Domestic Market) transmissions, it’s often recommended to use the solenoids from the original transmission. This is because the solenoids, which are electro-mechanical valves that control the flow of transmission fluid, may not come with the JDM transmission. So, it’s possible that the solenoids could be causing the issue if they weren’t transferred over from the original transmission.

As for the “shift improvement kit”, these kits are available for the Lexus RX300. They are designed to improve the shifting performance of the transmission. However, the effectiveness of these kits can vary, and it’s recommended to consult with a professional mechanic or a Lexus specialist before deciding to use one.

In conclusion, it seems like you might be onto something with the solenoids. It could be worth investigating further, perhaps by consulting with a mechanic who specializes in Lexus vehicles or transmissions. They can provide a more definitive diagnosis and recommend the best course of action. Remember, it’s always important to ensure any modifications or repairs are carried out by a qualified professional to avoid causing further issues. Good luck with your Lexus RX300!