Differential problem

I had a differential seal put into my 97 gmc 1500. I drove the truck about 200 miles. The differential came apart, a bolt broke off. Now I need a ring and pinion. I need to know what would have caused this.

Your post is a little vague. Did the bolt that holds the universal flange to the pinion break allowing the pinion bearings to unload and displace the pinion/ring gear mesh? Come to think of it, that flange is usually held on by a nut threaded onto a male tread of the pinion. So could you clarify what bolt broke

If the described pinion bolt did break, it was probably a defect in the bolt because overtightening would have crushed the pinion bearing spacer and overload the pinion tapered bearings causing them to overheat and sieze.

Also be a little more descriptive of how ‘the differential came apart’. What parts were loose when you noticed the problem? What was the nature of the problem and the symptoms you experienced?

Curious

Exactly what seal was replaced? There is more than one seal on a differential.