Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

2005 Subaru Outback transmission issue

I recently had my 2005 Outback (6-cyl automatic, LL Bean edition) in for its 60,000 mile checkups, which indicated no major problems, and then not long after had the transmission fluid flushed (the dealer did say they recommended this, but charged what seemed stupid money for the service, so I took it elsewhere).

But, immediately after that fluid-flush, the transmission has started acting weird. I’ve read up a bit on the power mode sensors/control system, and it seems as if the transmission control unit isn’t doing what it should at the shift that takes place at ~40mph - if I’m not applying much gas at that speed, it shifts up and down, lurching a bit faster than once per second, but I can prevent that from happening by giving it more gas. From what I’ve read (and only understand incompletely) it seems that this could stem from a faulty sensor or control unit, or maybe even a manually adjustable setting. My first question is, which is it more likely to be? Could the guy who did the tranny flush have dinked something up then? Should I take it back to the shop that did that and have them take a look, or (since they’re out of the way and I don’t have a lot of free time) is this likely something that another place could diagnose and fix quickly/cheaply? Also, is this transmission misbehavior causing any more damage?

If that flush was not done properly, it could definitely have caused this problem, so I would suggest that you take it back to the guys who did that job. For your sake, I hope that it was not AAMCO, Lee Myles, Cottman, Mr. Transmission, or any other chain.

Personally, I have the fluid changed–but NOT flushed–every 30k. My original Subaru is still perking along nicely at ~170k, as a result of that fluid change schedule and other proactive maintenance. My current Subaru’s transmission is also working perfectly at its current age of 7 years/95k miles, and I also attribute this to a fluid change (but not a flush) every 30k.

Just stick to 30k fluid changes in the future, and the car should operate properly, assuming that this flush did not do damage to it.

Who did the trans flush? If it was a transmission specialty shop I’d take it back to them. If it was a WalMart, tire shop, or quickie lube then I’d take it to either your Subaru dealer or a trans shop.

I’m not sure why you did the “flush” in the first place. Dropping the trans pan, changing the filter and refilling with fresh fluid is best way to refresh the fluid without causing more problems.

I suspect the fluid now in your transmission is not the proper specification fluid. A Subaru dealer would have used the correct fluid and a good transmission shop would use the correct fluid. Some of the other places that do flushes use “generic” fluids which they say are correct but in fact are just not the same as the mfg. spec. fluid. Improper fluid will cause the kinds of symptoms you are having, and in time can cause expensive damage to your transmission.

Transmission fluids are now very specific and differ from mfg to mfg. I play it safe and either go to the mfg dealer service dept for transmission service or a quality independant transmission specialty shop (not AAMCO). The wrong fluid(s) cause all kinds of problems, expensive problems.

If you are at or below 60k miles take it the Subaru dealer. This issue is covered by the powertrain warranty likely.

At the very least have you verified the transmission fluid level?

Thanks for the replies, guys.

I took the car back to the shop that did the flush yesterday afternoon, and they took a look at it, added a small amount (less than a quart, I think) of ‘conditioner’ to the transmission, and then the owner and I took it for a drive - and it shifted perfectly. The fluid level had been just at the low end of the ‘full’ range on the dipstick, he said, and apparently it was just very sensitive to that borderline low level. I’m definitely still paying very close attention to every shift, but so far, with about 25 miles of mixed highway/city driving - close to half of that right around the 40mph trouble spot - it’s been smooth as silk.

FYI, the shop that did the flush is a Meineke shop. I ended up there almost totally at random, because they happened to be across a parking lot from another shop I’d taken it to first, but which was too busy to do the tranny flush that day - and I really needed to get it done then due to tight vacation scheduling. The proprietor seems very knowledgeable - he knew a pretty fair amount about the various ‘historical’ Subaru transmissions - and was very helpful and accommodating when I came in with the problem, so I don’t have any complaint about their service. But I’m filing that fluid-level sensitivity thing away for future reference.

I’m a mechanic at a local dealership and for a brief time worked for meineke. I quit that job due to really shady practices and constant upselling of un needed repair work. I wont say all are like the one I worked for but most of the “fly by night” shops do the cheapest repairs they can or dont even do the actual repair. I would always recommend dealership first for major repairs or a speciality shop with a good reputation. Subarus are wonderful vehicles that if maintained properly will last an extremely long time but there powertrain is very sensitive. If proper fluids are not used in the transmission or transaxle it can cause major expensive repairs. I just had to replace a transmission and rear diff in an outback for this very reason. Customers got the trans fluid and diff fluid changed ar the local mienike ironically and they used the wrong fluid. It burned up the hydraulic clutch packs in the transmission and locked the vehicle in fwd mode only. The rear diff quickly developed bearing noise. Please be cautious and ask important questions about materials used before allowing service to be done.i agree with vDCdriver as well it’s honestly better to change fluid and filter for trans then to flush especially if the reason is do to shifting problems, discoloration or burnt smell.

1 Like