trans flush vs drain/refill

I’ve heard differing thoughts on this but here is my situation:

 

2008 Legacy GT 5EAT with 52,000 miles. Trans fluid is a medium brown, not too dark or light. So it’s probably never been changed. Transmission shifts ok except for the gear 2-3 shift shock that is common on this car.

 

I asked the dealer to do a drain/refill (my car is going in for a huge headgasket job anyway) and they suggested a flush. According to them, “Drain refill will not take old fluid out of cooler, torque converter or lines .A flush will.” They also claimed that the TCU relearn (commonly done to mend the 2-3 shift shock) is part of the flush service anyway. $190 for the trans flush

 

I’ve read on here NOT to flush it, and to do a drain refill at home.

Any advice?

I would recommend drain and refill NOT a flush (money maker for dealer). You could get a fluid extractor which sucks the fluid out of the dipstick tube. Remove fluid, fill and repeat.

would a flush harm the vehicle in any way/shape/form? TCU reset would cost about $100 anyways, so if a flush gets MORE of the old fluid out without hurting anything i don't mind paying $90 more

It won't harm it. I work at a dealership and I suggest them. Sure you can use other methods to get same result but they usually require lifting the car more than once. I vote flush. Since it would be 100 anyways ehat is another 90 to make sure its all squeeky clean?

Do the flush yourself. Its dirt simple and saves you coin.

Takes about 9 quarts.

m.youtube.com/watch?v=MsdPAadc9fY

 

You only need to jack up the front left wheel.

Do the flush yourself. Its dirt simple and saves you coin.

Takes about 9 quarts.

m.youtube.com/watch?v=MsdPAadc9fY

 

You only need to jack up the front left wheel.

 

Any idea where the transmission lines are on our car. I believe they are lead along the bottom of a vehicle and connect to the cooler connected to the radiator but I am not sure. I planned on just doing a dump and fill on my 05 this weekend but this seems to easy and I can get a good flush.

The tranny lines run from the driver side of the trans around the engine bay up to the rad. They connect on either side on the rad on the bottom on the inside ( closest to engine) I really have no iidea whysomeome would say flushes hurt the car We use a BG brand machine at our shop. I simply connect the cooler line and then the machine simply sits there and used the transmissions own pump to flush the fluid. So your not "pushing" fluid through with some crazy pressure... Your simply adding another p"pit stop" for the fluid to go to under its normal pressure... Only difference is as old fluid pushes in machine it pushes new fluid out. Most efficient flush. Yes at home versions can work quite well too but u really can beat a true flush. Ik we push 16 QTS through when it does it.

Its also easy to get to the trans lines right under the driver seat area of the car, they come out metal lines and turn into rubber with a clamp. You can easily take free from that location to pump out fluid. However I agree with 06leg315 on this, with only 52k on it I'd have no concerns with a flush, plus they do a re-learn, that's not a bad deal for 190. If it had higher mileage many people say you will have more material settled in the pan, etc and doing a flush "may" stir that stuff up and cause issues. So if higher mileage like 125+ then maybe do drain & re-fill, drive 1k miles, then drain & refill again. Cheapest you can get fluid for it is here IDEMITSU makes the fluid for Subaru. I got it from dealer and it has the name right on the back of the bottle. So your looking at at least 80-100 bucks in fluid anyway going this route.

^^ same place I tap into system at. As far as higher mileage I still believe its better for two reasons. A) youre not using an external pump to pump fluid. Your starting car and usingtransmissions own pump to push so anything it would stir up would happen regardless. And B) weflush 16 QTS which is well over capacity through system so that "stirred up" sediment gets flushed out in my book. Now that being said I totally agree it makes dealerships a ton of money... But on the other hand they own the 1500 dollar machine and we don't lol.