2003 Subaru Forester - replace or rebuild transmission?

Apologies if this discussion has been posted on the forum and I’ve missed it.

I recently purchased a 2003 Subaru Forester, automatic transmission. I had my mechanic check it out and they said that the car was “one of the best they’ve seen”. After driving the car for a few months the car began to shift hard (high and low speeds…all gears). Brought the car in and was told we need a new transmission. I asked about what specifically was failing, and was told that it’s not electrical (no codes show up) and that the fluid looks fine, so it’s some “mystery” mechanical issue inside the transmission (apparently they would have to tear the thing apart to find out exactly what is wrong). Our mechanic said that they recommend replacing the transmission with a Subaru remanufactured transmission. Took the car to another mechanic and was told the same thing. Finally, I called a big box transmission repair store, and was told that a rebuild - only replacing the parts that had failed - would be fine and “just as good” as getting a Subaru remanufactured transmission.

My question is: is it better to do a rebuild or replace the transmission with a Subaru remanufactured unit? The price difference is about $2k, although this gap could shrink if the big box transmission store found out that big ticket items need to be replaced after they tear into this thing.

Any suggestions or recommendations are appreciated. Thanks.

Before committing to anything I would suggest that you locate a long-established, independent transmission shop and have them take a look at it with a full scan.

The big box trans shop you mention should probably be avoided if they recommend a piece-meal repair on an 11 year old transmission. If the transmission was a year or so old on a near new car and warranty was involved then that scenario might be feasible. Otherwise, it could be problematic.

I’d replace it. You may be able to find a newer transmission out of a cracked up, parting out car.
Much cheaper.

A big +1 to ok4450’s comments.

Any advice from a “Big Box” transmission shop should be taken with a very degree of skepticism, and–unfortunately–the OP’s regular mechanics don’t have much expertise with transmissions.

Any indy transmission shop that has been in business for many years is much more likely to give you an honest diagnosis, good workmanship, and a fair price than any of those highly advertised chain transmission shops.

Thanks everyone for the thoughts and suggestions. We did end up taking it to an independent transmission shop. Same diagnosis but the mechanic was clearly more knowledgeable, did more diagnostic work, and took more time to explain things to us than any other shop. We put a remanufactured tranny in and it has been working great so far.