Subaru Outback shakes like Charlie Sheen in rehab

My Outback gets the DTs in the steering wheel. 2003 with 300K highway miles. New tie-rods, brakes, brake master cylinder, alignment & balance (all from great shop with great rep) have failed to eliminate the problem. It comes on suddenly at highway speeds, usually in cold weather (below 20); but not necessarily in snowy conditions. Slowing down to 30/20 mph does not stop the shudder (though it slows and reveals itself as a fierce twitch to the right – hey, maybe someone is listening to Glenn Beck in my car! Which would drive any Subaru to drink, no?). Eventually the shudder is accompanied by a rhythmic scraping sound somewhere in the left front wheel well, which maybe is there all along but inaudible at higher speeds. Help! This is scary! Shop sez alternator pulley is worn has 20K to go before replacing.

It sounds as though you might be suffering from a stuck brake caliper…Drive the car and get your thing to happen…then pull over and feel your lug nuts on the front wheels…if one side is HOT and the other just warm…the HOT side is the side with the stuck caliper.

That makes a lot of sense – because it seems to happen after some stop-and-go driving and once it’s cured, it’s cured for a while. If this is the problem, what’s the fix?

if you have a stuck brake caliper and that is indeed the problem, you must inspect the caliper to see if it needs replaced. First thing i would do is clean and lubricate the caliper pin slides. If they free up, you’re good. If the car still shakes there might be another solution to your problem here Car Shakes at Higher Speeds

Well, it’s not the snow, themidiman, and it’s not the calipers, Honda Blackbird. After over $500 to replace BOTH calipers, it’s still doing it. In dry weather. After sitting in a heated garage at work. Only seems to come on after about 30 to 40 minutes at highway speeds, which in Colorado is anywhere from 60 to 90 (though the car shakes mildly even at 65-70 after an alignment, which is why I seldom drive it above speeds of 75.) I’ve now spent over $1,700 plus rental fees to fix a problem that isn’t fixed. At this rate, I’ll have bought a new freaking car, part by part, and decimated a savings account I sweated bullets to build. I repeat, Help!

The trouble may be due to a tire defect. If you haven’t tried swapping the front and rear tires to see if that helps solve this trouble I suggest you try that. If that doesn’t help then perhaps the CV joints should be looked at as a possible problem.