Well this is interesting/discouraging/frustrating. I found this thread while doing some early research because I'm thinking of attempting the transmission fluid change next time it's due. I have a 2006 NA Forester with about 130k miles on it. After reading through this thread, I decided to look back through past invoices from the dealership (up until 120k miles, I had them do all my service to take advantage of their extended powertrain warranty). On the 30k, 60k, 90k, and 120k service, I'm noticing a line item for 4qts. of ATF/PS FLUID DEXTRON III (SOA635003). However, based on what Im reading here...and yes, in my owner's manual, they should have been using the Genuine Subaru Automatic Transmission Fluid IDEMITSU ATF HP or Castrol Transmax J all this time.
Now, I must say that I've been very pleased with the service department thus far, and I haven't had any issues with the transmission in the 130k miles I've owned the vehicle, but now I'm wondering if it could be even better with the right damn fluid in the transmission. I've only recently decided to do some of my own work on the car. But many people (myself included) tend to assume that even if they do overpriced work (and sometimes more than necessary), the dealership should perform the correct service and at least use the correct parts/fluids.
If I decide to go ahead and do a fluid change using the right fluid next time, is that likely to cause any issues? I'm probably just going to drain and fill, not flush, so there will be a combination of the two types in there for a time. Or should I just keep using the wrong stuff and hope for the best?
2006 Forester 2.5 X
L.L. Bean Edition
Regal Blue Pearl/SGM