hey guys, first post here, and im in Chicago. Just recently acquired a very nice GS430 2006, it had a very bad trans issue, that bent the input shaft, so I replaced a trans with a fully tested one. When I had it put it, reverse worked, I picked up the car 2 weeks later because I was traveling. I drove it to the tire shop to swap tires, and then reverse didn't work. Let it sit over night, and this morning I had reverse. Brought it to my job, parked it, and no reverse again? Someone mention Nuetral Safety Switch, and even shifter problems, but im at a loss.

 

Did you fill the fluid level to the proper level?

 

of course, the problems is, its fine, then its not, and its like either something is loose or.....

 

Could be a sticking reverse gear solenoid in the transmission. But, I wonder if maybe theres a gear selector arm came loose, or its not adjusted properly. See if theres an arm that links maybe a cable to the transmission.

 

Why not call the shop and nicely ask them if they could troubleshoot your issue?? Any pro should be saying yes come in we will take a look at it, and try to get to the issue to gain experience

Does the dash Indictate you're in Reverse? Like, it shows R, and car doesn't go anywhere? At all? Check engine on? If so there might be tranny codes too.

Lexus techdoc troubleshooting list only says to look at valve body and brake #4, some internal transmission part.