Well I found a 14mm x 1.5 thread pitch x 80mm bolt at the hardware store, but it was not grade 10.9.
I have it installed now as a temporary solution, and have a new bolt ordered from Toyota.
The local parts guy told me they usually have them somewhere locally in SoCal and can get them the next day, but it seems these are out of stock and will take 2 or 3 days to come in.
The rattling noise is gone, and the truck is handling much better as well. It felt like the steering was drifting a bit the last few days, must have been this issue.
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