Momentary Tranny Shudder

[gbhrps]

Recently I have become aware of what I think is a shudder in the automatic transmission.

 

I purchased this OBW LTD new in 07 and it presently has 95 000 km (59 000 miles). Its taken awhile for me to think that there may be something wrong, but I seem to be able to feel a minor shudder at certain times. It occurs when accelerating slowly or moderately and when driving straight ahead. I think it is at the shift from first to second gear and feels like the car has just driven over one of those warning rumble strips. Its just momentary and does not occur every time under the same circumstances. I would venture a guess at it occurring say every third or fourth time.

 

The car has run flawlessly since new and has only required the replacement of the tailgate Subaru emblem under warranty. The present Toyo snowtires would only have 20 000 km.

 

Does this set of circumstances ring a bell with anyone?

[Legacy777]

I'm not sure if my experience would relate, but I had an issue where I had a pretty nasty vibration. It only happened a handful of times and not for too long. Turned out to be the CV axles.

 

What kind of regular maintenance have you done on the car? When was the last time you changed the transmission fluid? Does the shudder occur under acceleration, deceleration, cruising? Does it occur when the transmission is about to up shift or down shift?

 

Any additional details you can provide would be helpful.

[gbhrps]

It only occurs when accelerating from a stop, and I believe the shudder is on the one to two shift, lasting about a second at most, and then only ocassionally. It has never occurred under any other circumstances. The transmission has never had any servicing done to it, other than to check the fluid level.

[Legacy777]

As a start, I'd suggest changing the transmission fluid and see if that changes anything.

[gbhrps]

Thanks! I'll give that a try and get back to you with the results. It may take awhile, since the dealership is 70 miles away.

[wtdash]

What's the powertrain warranty on your 2007? I think US models is 5years/60K miles....might want to take it in sooner than later to get it diagnosed.

[gbhrps]

I took the advice and journeyed to the dealership for a complete transmission flush, filter and fluid change, as well as a reflash of the transmission's computer.

 

The car has been driven perhaps 500 km since the service was done and the momentary shudder sensation has almost completely disappeared. I say almost because there may have been one or two times where I thought I noticed a much reduced shudder, but I can not be certain.

 

For sure the problem that I was concerned about has been dramatically reduced and may be eradicated all together. I'll keep you posted if the momentary shudder at the one to two gear change should come back.