2009 Chrysler Aspen, humming sound I believe is the rear end is getting louder by the day. How long do I have before my rear blows?

He just said it was OK but did not tell you what was going bad? The cost would depend on what the problem is. Ask the mechanic for the repair cost. I would not let it go too long as the damage could strand you or end up costing extra to fix.

Thanks for your reply. I brought my truck in for various issues, one was that it was too bumpy and sounded like something was loose. They put new shocks in, new tires, tie rod and then brought it back for wheel bearing, they put it in and took it out and told me the noise I was hearing wasn't the wheel bearing,it was due to my rear end going bad. They didn't say how much time I had before it went, just that it would get louder. I'm having a mechanic look at it tonight, hoping for a not too expensive repair.

It sounds like the differential bearings are going bad. If it has run a long time with bad bearings you may need new gears as well. I would install a rebuilt differential from a shop that specializes in rebuild differentials. If you plan on keeping the truck for a long time you might want to upgrade the differential cover to a high oil capacity one like Mag-Hytec sells to increase the life of the rear axle. http://www.mag-hytec.com/products.htm

Thanks for all your help. Can you recommend a used car parts place for the differential assembly. We just searched Car-Part.com and they don't have any in stock.

I can't recommend any but there are several that come up if you google "rebuilt differentials". Another alternative is to find a differential specialist in your yellow pages. Most mechanics don't know how to properly set up a differential when rebuilding them so a specialist is best.

Thanks again for all your help.