The problem du jour is that the check engine light came on after experiencing a jerking feeling while driving the car on the freeway followed by intermittent “no response to accelaration”. The jerking issue was examined by the local transmission specialist one weeks ago who reported no problems and no jerking. This same agent replaced the pinion berring (sp?) three weeks ago and advised the trani was fine. The car has 85k - what could it possibly be now?
Check Engine means check out the engine, and part of that is the computer. You need to have the car examined by someone with a code reader (AutoZone comes to mind) who can tell you why the Check Engine Light came on.
I agree with Mr. Josh about getting someone to pull the codes and try posting the results back here for discussion. These parts houses will do this for you free.
What makes me cringe here is why in the world a pinion bearing was replaced? These seldom go bad and even when they do there’s an outside reason for it; oil leak leading to loss of oil or extremely high mileage.
At a measly 85k miles a pinion bearing problem should not exist.
I would also point out that replacing a pinion bearing on a Subaru is not simply a matter of yanking one out and throwing a new one in. This job requires some special expertise and special tools; at least if it’s done right.
Just curious, but what were the symptoms before, did this guy pull any codes, and is this vehicle an automatic or manual transaxle?
The initial transmission symptoms were: A 'wah, wah, wah, sound when foot off accelerator when getting off freeway. And a horrible metal grinding sound all other times. The AAMCO folks diagnosed the pinion bearing and replaced it. Noises went away, car ran fine, until a week later. Then the weird halting feeling started happening. I had a tech check out the code yesterday - it’s the TPS (or TPL) sensor on the transmission…apparently it’s going out and the transmission is confused about when to shift. This car is an automatic.
Your “local transmission specialist” was AAMCO? That in itself gives me reason to doubt the diagnosis that you were given.
If you want an inkling of my reason for saying this, please refer to ok4450’s comments above regarding replacement of a pinion bearing on a Subaru. OK is a master mechanic, certified on aircraft as well as automobiles, and he knows of what he speaks.
You really need to get a second opinion from a transmission shop with a good reputation–and that does NOT include AAMCO, Lee Myles, Cottman, or any other chain with which I am familiar.
Seek an independent transmission shop that has been in business for at least three years. A competent transmission shop will tell you if the issue is not transmission-related, and may give you a good referral for a different shop. Ask friends, relatives, and co-workers for suggestions regarding an independent transmission shop.
A faulty TPS (Throttle Position Sensor) can cause jerking, erratic idle, and similar engine programs. It is on the engine. You should get out the door with its repair / replacement for about $100. It’s a job for an engine mechanic.
Still pondering this (and cringing even more) but to make sure we’re on the same page here, how many bearings did they replace?
Was the transaxle removed and torn down for this repair or are we talking about what I call carrier bearings? These carrier bearings are sometimes called pinion bearings (erroneously) and there is one on each side. These can be changed without transaxle removal by removing the halfshafts. Still, it’s not supposed to be a yank em out, throw em in process.
The only pinion bearings, or carrier bearings, I’ve seen go bad were ones in which the final drive of the transaxle was run out of oil. In these cases, the ring and pinion gears were also damaged.
I sincerely HOPE this shop is aware that an automatic transaxle on a Subaru basically has 2 compartments; one for ATF fluid and the other for hypoid gear oil.
The latter has been known to leak out of the final drive compartment over time.
If you’ve got pinion or carrier bearing damage then it’s quite likely the entire final drive is toast.
Here’s a pic of a Subaru transaxle. Note the hyphen between the 1 and 8. See the round toothed bearing holder right above the hyphen? There’s a bearing behind that (and on the other side too). Is this what they changed?
Note that dipstick? That’s for checking the final drive oil level, NOT the ATF. Some Subarus do not have a stick. If yours does then I would advise checking it PDQ.