2004 Subaru Outback noise when in reverse

subaru
outback
noises

#1

I have an automatic V6 2004 Subaru Outback and recently when I put it in reverse it made a hard “thunk” noise and there is a minor noise when reversing. When I go in Drive it goes away and no issues when driving straight. Any experience with this or suggestions?


#2

I can’t offer you any real help but if that happens again I suggest you have the car looked at as soon as possible by a good shop. You don’t want to have repair bills for a serious drive train problem which can get worse the longer you put it off.

BTW, the engine is really an H6. Horizontally opposed. You have a nice car there.


#3

Did that “thunk” occur only once, or is it an ongoing issue? Were you parked on a hill or a grade when you heard the “thunk”?

How about the noise that you hear when driving in reverse–please describe the noise, and tell us if it was it a one-time occurrence, or is it ongoing.

The “thunk” could indicate a worn u-joint in the driveshaft running to the rear wheels, or it could just have been the “park pawl” disengaging roughly due to parking on a grade.

If there is an ongoing whining noise when driving in reverse, that could indicate a problem with the rear differential.

How many miles are on this car’s odometer? Did you have the differential oil changed as part of the 30k maintenance and the 60k maintenance?

Incidentally, that engine is not a V-6. It is referred to as an H-6, due to the horizontally-opposed layout of the cylinders.


#4

It may still be under warranty (5yrs/60k), if so go to dealer.


#5

The car has 70,000 miles. It is no longer under warranty 36,000/36 mo. The “thunk” happens once after putting it into reverse and then goes away. Once I am in drive there is no noise. There is no whining noise in reverse. I will check the differential oil. I know it is a H-6 just typed it incorrectly.

Thanks for all the advice.


#6

The car has 70,000 miles. It is no longer under warranty 36,000/36 mo. The “thunk” happens once after putting it into reverse and then goes away. Once I am in drive there is no noise. There is no whining noise in reverse. I will check the differential oil. I know it is a H-6 just typed it incorrectly.

Thanks for all the advice.


#7

If you hear the “thunk” once when the car is put into reverse, and it then goes away, I would suspect a bad u-joint, rather than the differential.


#8

The warranty is 5yrs/60k on the powertrain. If you performed the 60k service at a Subaru dealer you may be able to get Subaru to pay for part of the repair if any.


#9

So is a u-joint a large repair? Is it considered wear & tear vs. a mechanical problem?
Thanks-