My 8.7 inch clearance AWD Subaru Outback made it completely up the road to the TH with careful and slow driving. After leaving the Silver Creek/Grizzly Gulch trailhead, the road is pretty rough in some spots. The road description states that it is an easy 4WD to 11,300‘ at the turn off for American Basin, but I would disagree. There are some spots where low-clearance vehicles may have difficulty getting over rocks. I would not suggest any low clearance (2WD or 4WD) should attempt this road unless you are a very careful and smart driver who is aware of the possible difficulties. Once past the American Basin turnoff at 11,300‘ it is definitely still difficult (photos #1 & #2). The creek crossing (photo #3) isn‘t very deep so it‘s not bad at all. Best bet if you want to approach this TH is to find a good clearance 4WD car if possible.
See attached photos and video (video is from the "easy 4WD" section):
Photos (click for slideshow):