Hi Scotty, I have had a 2008 Lexus is 250 AWD with 140k miles for about a year now, when I first bought it, it had quick acceleration and could shift perfectly in gears, But nowadays I feel like it struggles to pick up and also kinda struggles to shift the gears( gets loud). I took it to a local import shop that suggested that my transfer case is getting weak and should be replaced. So i thought of draining transmission fluid( it has a sealed transmission) to see if there is any changes before spending money on replacing the transfer case. What suggestions do you have that i should do to solve the issue?
If you are already having trouble with the trans, flushing out the fluid may buy you a little time. Just be aware that it could also lock up the trans requiring an immediate rebuild.
As for lack of power, have you changed the spark plugs on time? Cleaned the throttle body and mass air flow sensor? Checked to see if the fuel filter or air filter is clogged? These little items can make a big impact on performance.
Do not flush the transmission. You may not have transmission issue. You may only have issues with the air/fuel mixture ratio.
@yaser
Air/Fuel ratio problems wouldn't have a bearing on the transmission shifting issues. So not sure why the downvote on my answer. Air/Fuel issues could play into the lack of power part of his problems though, especially if all the maintenance is up to date.
You recommend to flush the transmission, it is really not a good idea unless you are 100% sure your that the issue is the transmission and it can not be fixed without flushing. Correct?
servicing the transfer case won't help your acceleration
