Crank shaft pulley bad?

On cold startups, the engine makes a minute or so of intermittent groaning grinding type sound that goes away fairly quickly until the next cold start. Here’s the strange part. While making those sounds and driving, it almost seems as if the truck lunges a little (my imagination?). Would a dying crank shaft pulley possibly cause what I interpurt as an actual momentary change in acceleration (only during hearing the intermittent sound)? 125k miles and it’s not dirty down there with no oil leak or dirt that I can see messing it up (I don’t off road, mild climate). Aren’t they supposed to last the life of the truck unless that area gets fouled up with dripping oil and dirt (not the case here).

 

Is it wobbling? They go bad over time the rubber deteriorates

 

I thought I noticed the belt moving a little on the pulley, not much tho. Gonna check that again.