My friend has the aforementioned truck and IIRC said it has around 120k miles on it. She often drives it in fairly dusty conditions. She says it sounds like a bucket of bolts when being driven, with reference to the suspension system. (She's pretty handy and thoughtful, so I believe her when she says she thinks it is the suspension system.)
I suggested checking the rubber bushings in the control arms (assuming they exist; they do in my old Honda); the engine mounts (not the suspension system); and maybe the ball joints (though she and I think she'd more than likely see a catastrophic outcome sooner rather than later if the ball joints were failing).
No particularly unusual noises emanate, suggesting, say, a failing CV joint. It's simply not as smooth a ride as it once was.
I will be googling but would welcome any impressions folks here might have.
Can anyone else suggest other areas on which to focus for this particular older, Toyota pickup truck to give it a smoother, less noisy ride?