I recently changed my transmission oil and today i just go to one shop for free inspaction and he told me my transmission oli is dirty and needs to be flush.Some people says flush will screwd my transmission.please advise.My car is Sonata 2002 and milage is 116k

It is a myth that trans mission oil never needs changing
All oils oxidise under extreme heat conditions ( and transmission oil reaches very hot temperatures) and bearings, bands and clutches do wear
again flushing is a general term incorrectly used
A transmission oil change generally removes the oil from the pan area but leaves 1/2 the torque converter with contaminated oil
That in turns re-contaminates the fresh oil
Flushing on the other hand is expensive as it require a considerable amount of new oil to do the job It is done with the engine running and fresh oil is drawn in as the old oil is pumped out
so you have to decide to have it changed or flushed as the difference can be in excess of $200.00 dollars BUT the results are also very different
Many manufacturers run sealed transmissions , for the sole purpose of preventing DIY people from putting in the wrong oil and so causing a problem in the transmission
remember that you most probably have a CV transmission
Constant velocity) which utilizers a drive belt between 2 pulleys and requires a special transmission oil as well
The transmission performs similar to the old automatic transmissions but is vastly different in internal construction
Normal period for a change ( depending on speed and operating conditions ) is 60,000miles so talk with an accredited specialist transmission shop to get an idea as to what is a good idea on oil changes

please do not have your transmission flushed , have someone take the oil pan off and replace the filter as well and what ever trans oil you take out replace it as well . no automotive repair shop will warrenty your trans if it should suddenly stop working , but just for your satisfaction ask the transmission repair shop who flushs trans if they guarantee it and have them put it in writing . ive never understood why flush dirty oil and leave the dirty filter in the trans , it collected all dirt and metal wear which is what is causing it to plug up causing it to restrict the oil flow

Hi Lb,
My car is RX300 1999 and has the same problem. I changed the fluid 2 years ago after the trans slip and lost the shift. Afterwards it worked for another 2 years. But recently it doesn't work again even I change fluid and put Stop Slip additive to the trans. I was told the trans has to be rebuilt. So changing fluid and filter can help to maintain the trans for sure and can prevent problem. But if the trans has already worn a lot, it can't help at last.

lots of transmission problems today ...I am going to help you...?? have you had all transmission fluids ,filter changed recently ...if not do it ...first go to an autozone if you have one and have them read your sensor codes free ,,maybe you just need new shift sensors ..I would still service the oils in your transmission as well as a new module

oh man ,,,just change the transmission filter screen under the transmission ...you will get greasy and dirty ,,put your new fluids in and see how well it drives ,,unbelievable

Please follow the experts recommendation . In Automatic transmissions are not using thick oils. Only special and manufacturers recommended oils are used. If you will not change it you will come surely to an unexpected and not worthy situation. Proceed as you been told . Renew the oil and filter and I again inform you to use the specified oil from manufacturer and nothing else.Also it is better to put into your automatic gear box if you can find the " Wynn's Automatic Transmission Treatment. "It will help a lot.

before you waste money on the mechanics word , take it to a professional auto transmission shop for a proper diagnosis and quote
if only one gear has a problem , it indicates a possible clutch pack / band adjustment or solenoid /servo problem or even dirty oil

you should have checked the transmission fluid first .change it if black as dirty fluid can give you a sticky solinoid in the gearbox

you dont need a complete oil change.
the other oil will also lubricate, so the oil you have put on, is as good as the oil who was there before

it all depend on the millage, and how dirty the oil is

if oil very dirty it will be worst for your transmission