new rear end going bad

does anyone have any idea why a recently replaced rear end would start to go bad after only 2 weeks?

does anyone have any idea why a recently replaced rear end would start to go bad after only 2 weeks?

Welcome to AF
When posting always give year make and model and engine and mileage and 2W or 4W.
Try to describe what it is doing or not doing or noise it is making.
Also repair history.
Was the rear end a used or new or rebuilt or repaired?

Always check the fluid level first thing.

Here is a link to a rear end repair by symptom site.
Lot of good info on the site.
http://www.differentials.com/install.html

New or rebuilt, if its not set up properly, it will burn itself up very quickly. You have to have a qualified person to check this. Also, make sure the oil level in the differential is where it is suppose to be.