i took my car to the shop to have the rear bearings changed and my mechanic just called me to tell me that they saw metal shavings in the differential , question is how bad is this?

 

Depends, how much metal? If it's the same amount as the size of your thumb nail, I wouldn't worry about it. The gears will slowly wear down and so you are going to have some metal. If it is metal chunks that is different. I would be worried about that, or if there was a lot of metal.

 

Exactly which rear bearings were you having changed and did you have it in the shop because of a noise back there?

If you were hearing a rumble in the axle and the mechanic is simply telling you what he is seeing after pulling the axle cover then the next step is for him to determine what is happening. If you have a bad carrier bearing it will be crumbling and you will have metal debris. If the bearing has gone really bad you could be looking at replacing gears as they too will be grinding up.

If you have a bad axle bearing I would think that some of the debris could work its way into the axle housing. Replacing axle bearings is not that bad news.

If it is the carrier bearings that need to be replaced you could be looking at a few hundred. If the rear end has to be rebuilt you can expect to spend significantly more.

In other words, you need to know from your mechanic what is grinding up. When he tells you, post the news here and someone will be able to tell you what it should cost to fix. You need to keep up with what is happening to ensure you are not being lead astray on your actual repairs.

Regardz