'93 legacy, AWD A/T, 165k
I am not exactly sure how to describe this, but my legacy has started to misbehave when accelerating, typically when going up a hill. When additional power is requested (on a hill), it feels like the front wheel(s?) just won't hook up. It makes the car buck/lurch for about a second, but then it seems to hook up and drives okay. It feels like some kind of drivetrain issue to me. This has been occuring for about 2 weeks. At first it was very intermittenent, but now it happens almost every time I apply power when going up a hill. It has happened on the flat a couple of times recently, especially starting from a stop.
Also, in the morning when it is cold, I hear a faint noise that sounds like it's coming from the front left. It's kind of a wah-wah-wah sound and it seems to be in time with the front wheels (speeds up/slows down with the speed of the car). It sounds different from the bad wheel bearings that I've heard before; it just doesn't have that grinding noise.
Today, on the way in to work it scared me a little. It was feeling a little bit loose and floaty, and suddenly pulled very hard to the right. I was in the truck lane on I-5, which I don't typically drive in because it's so bad, so it could have just been the ruts in the road. I did pull over because I was envisioning losing a wheel bearing and causing a big wreck. I shook both front wheels and didn't feel any play at all. There was no noticable heat or smells, so I continued on and it seemed okay (no more loose-ness).
I replaced both front axels with MWE's about 10-15k ago.
What could this be, and how would you go about diagnosing it? I plan on putting in the FWD fuse on the way home to see if it helps. My tires are pretty old and could be out of spec, and the tranny and diffs could all use some fresh oil. I can measure the tire circumfrences and change the oil this weekend.