Add one more to the list..
History:
On 11/12/2013 I signed the paperwork to purchase a used 2010 Subaru Outback from Marin Subaru in CA. VIN number: 4S4BRBCC7A3370146. As a condition of sale I requested the full steering wheel shake TSB number #05-48-10R be performed. This was put in writing on my bill of sale and I was assured it would be completed but that I would need to leave the car with Subaru for a few days.
While Marin Subaru did put a new set of tires on the car, which did stop the wheel from visibly shaking -- the shake was still there at highway speeds, just diminished. I made the mistake of not pitching a fit.
I noticed the shake most at certain highway speeds between, 65-80 miles an hour. The violence of the shake only got worse with the more miles I put on the tires until no rotation or balancing could get rid of the shake. I had a new set of Michelin tires installed 10/27/2013, and this again reduced the shake to a similar level of when I took delivery of the car with the new continentals.
I brought the car into Marin Subaru to have the TSB preformed that was promised by General Manager Tom Donnelly when I purchased the car. They did the typical RFB and alignment charged me $200+ and said the car was ready.
If the same pattern continues, which I suspect it will, within the next 4-6months once my tires have worn I will have a car that shakes much more considerably despite rotation and normal balancing.
In addition to the shake at highway speeds, my car also exhibits a pulse in the hydraulic steering system that can be felt, at slow and high speeds. The easiest way to feel the pulsing is to turn the wheel from side to side (one second to the left one second to the right) while driving at 40mph on a smooth section of road. The sensation is as if the hydraulic system is pulsing. The pulse happens whether the car is in gear or neutral.
While I cannot say if the pulse and shake are related, both are occurring.
I realize that preforming the TSB will not necessarily solve the problem in its entirety, but it will very likely, help reduce the vibration if performed in full by the installation of the dynamic damper in the steering wheel, new steering column, additional bushings/inserts and the stronger steering gearbox sleeve spring.
I have requested the TSB 3 times now. Once when I bought the car, and the last two times I brought it in. This last time I wrote them a letter and documented it. While they have said my car does not have the high speed shake they are "looking into" the pulse. Hoping they don't come back with the standard this is normal answer.
I have spent hours on this board reading even carefully poured over changes in the hydraulic steering system in various Outback service manuals. The only hint I can find is that Subaru has long employed a power assisted rack and pinion steering system with a rotary control valve, vane style pump, relief valve, flow control valve and either a pressure sensitive valve or pump control valve. On the 4th generation outback they have installed dual damper valves on either side of the control valve. I find this interesting. While this has no relevance at the individual car level from engineering perspective this is a notable attempt to reduce vibration that has failed.
Advice welcome, my bumper to bumper warranty expires soon.