I've got a brief update.
I was able to crawl under the truck tonight and poke around.
I'm leaning toward it being an oil filter leak (for a few reasons).
- Brakes feel good- brake fluid booster/reservoir is full
- Garage floor is stained & water beads on it (sure looks/behaves like oil). When I put enough water down to puddle, there was a thin layer of pearlescent/rainbow oily fluid on top
- Power steering feels good (very light) and fluid level is normal.
- Turning the wheels full-stop produced no fluid under the truck near the bars or boot
- Didn't see any fluid leaking from the R&P
- I'm not ruling out the diff, but there is fluid well above the diff on the left side of the eng. block (below the oil filter)
Here's a video I took while under the truck:
The Leak - YouTube
(Video is still processing so give it a minute if you're viewing shortly after post)
I've attached some stills from the video as well.
I'll pull the skid plate off tomorrow and do an oil & filter change. I should know pretty definitively during the filter change if that was the culprit.
Thanks to everyone for the input. I'll update again after a filter change and some light driving.
P.S- How bad does that rust look? I've only had the truck for about a month, and it's my first 4Runner, so I'm not sure how much rust is "acceptable". It appears to be surface rust, but I'd like to know if I should be worried...