Esko

2003 gs300 transmission shifts hard from 3rd to 4th gear fluid is blk I have no codes on transmission or engine someone please help before I drain the old fluid and add new fluid purchased oil from Lexus dealer ship pan and gasket as well for transmission thank again

TrueGS300

How many miles on the car? I hate to say it but if the fluid is black its probably done for. But maybe not in this case. Usually if the fluid is still relatively clean it can be worth a new filter and fluid, but black fluid is from the clutch material burning up. New fluid won't fix that. But if you aren't experiencing slippage you may get away with new fluid and a filter. Here's why; hard shifts are from an accumulator problem. And if there are no codes it isn't a electrical problem with a solenoid. You have blockage in the valve body port leading to that accumulator or built up in the accumulator for 4th gear making it not do its job to cushion the shift into 4th. Since trans fluid has the function of a detergent, you maybe get lucky and break this gunk up. But you really should be flushing the entire system out with a fluid exchanger that gets all the old gunk out and runs new fluid through the valve body while the service is being performed. We even run a trans cleaner at my shop for these services that breaks up gunk in there and is flushed out with the old fluid. Only by getting all the old junk out will you have a chance for the new fluid to work through the system and break up the blockage. Once the fluid can make its way through the ports again you should gradually feel the shifts get smoother as the accumulator starts to work again. There's no guarantee. The spring for the accumulator may even be broken. Obviously nothing but removing the valve body and replacing it would work if that's the case.

Now the one down side to this is that you may only "not" be experiencing slippage right now due to the fluid being in the state that it is. Once the old fluid is out (along with all the clutch material in it), you might start to experience slippage. Then this was all a big waste of time and money. Thats why I'm asking your mileage and if you know if the fluid has ever been serviced? Depending on mileage and the state of the fluid, we may opt not to do a service. Especially if the car is experiencing problems.

Alphaman19

“Brrmp” - Sound of TrueGS300 dropping the mic.

Esko

i, just now seeing this i really appreciate the feedback i have 272,569 miles ive done alot of work to this car and would like to keep it idk what to do i am completely lost i was gonna give the car to my daughter but i guess thats a nogo please respond when you can for now i need to drive it until i get something else

lexo98

iTrader: (2)

Try to do a couple of drain and refills and see if the prob goes away