Well thanks for pointing that out, and I currently am mostly driving on the pavement and some country dirt roads. This is my daily driver and I can't be wheeling it hard and risking breaking things. I wouldn't to that with this truck even if I had a new truck as a daily driver. I've driven this truck for 24 years and plan to have it still running and in good condition in another 24 years. I know what it is capable of as well as my own driving skills so I don't feel I have to prove it by beating it up on the weekends. If that's what I wanted to do, I would buy another 80 and prep it for that type of use primarily. Turns out, aside from the metal shavings in the front diff and the axle seals failing after only 30K (front and rear axles rebuilt along with new brake calipers rotors and 100 series pads and more was done with the motor rebuild), but I don't know if i mentioned earlier in my post because I have been hyper focused on the Diff oil contamination and metal partitals, but I did discover that my DS front wheel bearings had a little slack and needed to be readjusted. Not sure how long it was loose but the spindle shows that the rear wheel bearing race was spinning on the spindle and caused a lot of heat on the front and back sides. That may have contributed and started a chain reaction of failures in the spindle bushing, birfield heating up more and allowing grease to enter the axle housing as it cools and diff oil getting back into the birf. I was told that because I am running 35's, I should be servicing the wheel bearings at least every 30K, re-pack and set preload. I notice also the dust cover and seal is wet too. I guess I should replace this spindle with a new one with the bushing already installed. The other side is fine and that wheel never loosened up.View attachment 2660698
That spindle is not great, but not horrible either.
You could clean it up with some fine emery cloth tape and run it.
I've run with a lot worse without issues.
Do some reading about setting wheel bearing preload. With big tyres, this becomes a critical adjustment for these vehicles. The FSM preloaded method is not reliable.
30k service interval for bearings is ok. Service may consist of jacking up a wheel, checking for play, and remove drive flanges to check condition of grease.
Some of the noises you describe sound consistent with loose wheel bearings.
Growling on deceleration is a typical symptom for dry or worn uni joints.
I also agree with other comments that replacing R&P without draining and refreshing diff oil a couple of times sounds premature.