Ive got an '01 and the trans fluid is registering about 3" over the full line on the dipstick and today it seemed to slip going into first from reverse right as I was pulling out of the driveway but then was normal once it came up to operating temp. Fluid looks/smells clean and had a tranny service done at Lexus less than 20k miles ago by previous owner. Could it being too full cause this issue?

 

Not sure but curious as '06's don't have a dipstick.....is there a hot and cold range on the dipstick? One would think a dealership would not overfill, and there would be no reason for the owner to add / top off.....could it be 3" over when hot, on the cold min max....

 

The proper way to check trans fluid on the 01-03 LS430s is to wait 30 minutes after an extended drive and check level. Anything between the two lines is acceptable but I have kept mine right at the upper mark.

 

An overfilled trans will cause all kinds of havoc as the oil in the trans will be up that high that the grars will be bathed in it, and them spinning will foam it up, foaming oil definitely wont work right.
The best thing to do would be to drain and refill to correct level.

 

I would rather have my car be under filled and then overfilled, remeber oil expands with heat.