My 2001 GS430 with 98K miles on it had difficulties engaging reverse in the morning or when the car sits for more then 4 hours. It would take a 30 seconds to a few minutes sometimes for reverse gear to engage when cold. When the car warms up reverse engages with no issues. No slip or engage issue for all the forward gears. Took to the Lexus dealer and they wanted $3700 to do the rebuild. Search the internet and found a product Lucas Transmission Fix. I was a bit skeptic about possible being a snake oil product. At this point I was thinking the worse it can do is to do the rebuild now than later. Going to replace this 11 years old car later this year so I didn't want to spend any major repair on this car.

Boy was I proven wrong. Did a complete transmission fluid exchange using a MOC Transmission flush (replaced 100% of the fluid). Had the dealer add the Lucas Transmission Fix additive. The product has a honey like consistency. The tech mixed the Lucas with Type T-IV fluid to thin it out. Total cost $268 ($244 for flush and $24 for Lucas Transmission Fix). Driving out of the service notice the shifting was very smooth. Next morning I started the car and shift to reverse. It engage immediately with no jerks. Will see how it holds up next couple of days or weeks.

At this point I highly recommend this product.

Chu...

 

glad it worked for you and your car is running smoothly; but the hundred dollar question is what helped more, the flush or the additive?

 

Yes it could be the flush or the additive. I am happy either way for not having to spend $3700.

Had the transmission fluid drain and fill (not full fluid replacment) a year ago to fix a shifter seal. Problem of delay reverse engagement has always been there before the seal fix. It has steadily become worse until recently.

After 2 days I notice some additional improvements. While coasting on the road with the foot off the accelerator then depressing the accelerator I notice the is less slip (rpm does not rise as fast as it engage a bit quicker). On idle at stop light the engine does not shuttle (very faint before) and now it so smooth I you have to look at the tach to see if the engine is on or listen to the exhaust.

My guess is that the Lucas Transmission Fix additive coats the transmission bands and fill in the worn surface a tiny bit to help engage the reverse gear. The viscosity and tackiness may help hold some transmission fluid when cold or sits for awhile.

 

I have this exact same problem in my 01 gs3. I will try Lucas today. Thanks for the info.