I’ve been having some drive line vibrations around 50 mph. I checked the U joints and replaced the center support bearing - which helped some but it still has the vibration.
I decided the only way to pinpoint it would be to get it up on jack stands, start it and run through the gears. Nothing significant until I got to 4th gear. At that point, it sounded like someone put a big rock inside the diff. I checked the oil level and it was good.
So I drained the oil, pulled the cover and everything looked great - no metal in the oil and nothing seemed loose. Restarted it and same thing - when idling in 4th gear, it sounded like it was going to fly apart. Examined it a second time still looking for something loose and found nothing.
At that point, since the only thing I couldn’t see was the pinion bearings I pulled the carrier out to get a look at those. Started it and tried again... all gears smooth and quiet.
So, I took the carrier apart and I see absolutely no reason for this thing to sound so bad. Are these things just noisy by nature, or am I missing something?
