so i changed a little over half of the fluid and it seems to shift a little smoother. is there any reason to gradually change the fluid as some suggest? or is it better to get all new fluid in?

Thanks for the advice. i would not say the fluid is black, but it definitely brown. So is there no truth to the story that the transmission utilizes dirt/debris as a friction enhancer as it gets older? i read something to that effect on a ipd transmission flush kit.

I have a 2001 s40 nearing 130k miles. As far as I know the transmission fluid has never been changed. Occasionally, when driven in heavy traffic for 45 minutes or so, i'll experience some hard shifts. Is this something that a transmission fluid drain and fill would fix? Or could it be some other pro...

Thanks! i've gotten the sludge out of the immediate exterior port but do i need to clean beyond this? there is a small hole that leads to inside of the engine block. can i damage anything by trying to clean in there?

I'm in the middle of a pcv replacement on my s40. When I pulled the oil trap off, I noticed the port on the engine block (that connects to the oil trap) was completely blocked with deposits. Does anyone have any advice on cleaning this connection into the engine block?