pinion bearing destroyed
A month or 2 ago I reported my D90 refusing to budge from a stoplight, as if the brakes were engaged. Eventually got the rig moving with strange noises coming from the front axle. Vehicle got towed home. CV joints were okay. Eventually I removed the front differential from the axle and took it to a shop. The cause was a pinion bearing that destroyed itself. See pic. The thing got so hot a roller or two fused together, and you can see the heat damage in the carrier. In the process, bits of the pinion bearing also pitted the other differential bearings. Ended up being a $700 rebuild job.
Not sure how avoidable this wear and tear was. Rig had 160k miles when I bought it and I changed the axle oil. I remember hearing a whining noise from the drivetrain at highway speeds but the rig is so noisy I couldn't tell if it was normal or not.
Thinking of taking off the rear differential and hand spinning it to test it out.