What happens when either your front or rear differential gets low on fluid? How does the car react/ride? Will the car just halt or grind or explode??? Well, maybe not explode, but how can you tell if there is something wrong?

My daughter-in-law's Jeep ran very low on rear-diff oil, and the diff suddenly seized up miles from home.

 

I suspect that there must have been some warning noises, but by that time the damage is done anyway.

 

What can I say? Check the oil-level occasionally! If it's not leaking, you don't have to check it very often.