marinerfan

Hi everyone - first post here. Thanks in advance for your insights. A few years back we bought a "beater" 2008 Fusion SEL, V6, AWD to see if AWD would help at our new house, with a steep driveway that we couldn't get our poor old Taurus up in the winter months. This car is super fun to drive and amazing in the snow. But the list of issues I've had and poor MPG (around 18 mpg to/from work, which is about 10 miles of mostly flat 55 mph driving. When I am on the freeway at 70 mpg I can squeak out about 23.5-24 mpg) make me hesitant to pursue heroic measures to keep it running. This car had a rebuilt title and needed some work (power steering pump, rack and pinion, seat belt pretensioner to get the airbag light off, new blower for the heater, 1 new ignition coil. Maybe a few other issues, can't remember). We got the car fixed up and have really enjoyed the vehicle, however we really only drive it in the winter months. The seat heaters are both burnt out as well, not planning on fixing that. Recently I took it on a drive to get the cobwebs off before this winter and noticed some excess road noise from the back end. The tires were in really bad shape so replaced those, which didn't help at all. Figured it was a bad bearing so took to the mechanic. Their workup is saying the wheel bearing might be bad, but they are much more suspicious of a "pinion bearing" going bad. My mechanic says he's never seen this in this model car and apparently you can't really just buy that part unless you find one at a junkyard - I think he said we'd be looking at probably an entire rear differential replacement as the most likely approach (I'm not super mechanically inclined, does this sound correct??). My mechanic said he doesn't think using it as a daily driver will cause catastrophic failure any time soon, but recommends against road trippin' in it. We'd be driving the car about 10 miles to work and back each day. He is trying to see if he can find the pinion bearing only to get me a quote on replacing it, if possible without doing a huge overhaul to the back end. Otherwise, the mechanic said the car looks and sounds great - he thinks engine and transmission have lots of life left. I've never had reason to doubt my mechanic, I've used him exclusively for about 5 years now. Considering I have 2003 and 2004 Ford Tauruses, I see him pretty regularly lol. The car also has a newish oil leak (it's a severe leak that needs fixing) and antifreeze leak and is due for a tune-up (almost 90k miles on odometer) - I haven't gotten a firm quote for this work but got the impression it'd be around $500-700. He said the transfer case and timing cover have leaks, and he'd have to pull the engine. I'm trying to decide what my best play is here and would love some opinions, if anyone has any experience with pinion bearing failure in these vehicles, or ideas for a cheap-ish fix. I'm leaning towards getting the tune-up, getting the fluid leaks fixed, and ignoring whatever bearing is bad, for the time being. If the car does well and we see marked MPG improvement after the tune-up, probably inspect the wheel bearings in the spring. The other route, if you guys think this will be a big deal to fix, would be to ditch the car. We can afford to replace everything but I think it'll be hard to justify the expense (mech said maybe $2000 for the back end if we can't just replace the bad bearing). If I *have* to sink another $3000+ into this car, I'd cut my losses and buy a new vehicle. Thanks for your advise and ideas!