Anyone experianced this problem before. I own a 98 concourse and recently had the alternator rebuilt. The place that does the work is very good. In fact the upped the amperage to 160. Well Im now on my 2nd set of bearings in the alternator. The first problem happened like 3 days after they rebuilt it. This second time it was like 4 months later but the same problem. They told me this is not rare and normal for cadillac alternators. Any ever have this problem?

Why don't you post this in the electrical forum or the forum for your model car instead of the Northstar engine forum? You'll probably get better answers anyway.

I saw a similar problem once, but it was with the idler pulley. First time around the customer did not want to replace the idler with the aftermarket equivelant which is metal and does not have that small lip around it. The factory one was making noise, I replaced the bearing, and he came back a month later. The bearing had jammed and the pulley melted. We went the aftermarket route and changed to the metal design. He left and about 2 months later returned with a noise, and clearly the pulley was swiveling. I said no was 2 idlers can go bad, so I began to check everything seemed fine, and upon reinstalling the belt I felt the tensioner kink. To make a long story short, the tensioner was faulty, even though I checked it out the first time I changed the pulley. It would kink intermittently. The tensioner was not loading the belt on the pulley correctly and was damaging the bearing.

This could be your problem, or it could be that the people rebuilding it are not installing the bearing correctly. Check out the tensioner, it's worth a shot. It solved my problem...

Anyone experianced this problem before. I own a 98 concourse and recently had the alternator rebuilt. The place that does the work is very good. In fact the upped the amperage to 160. Well Im now on my 2nd set of bearings in the alternator. The first problem happened like 3 days after they rebuilt it. This second time it was like 4 months later but the same problem. They told me this is not rare and normal for cadillac alternators. Any ever have this problem?

What is the failure mode of the alternator bearings....??? Are they overheating and burning up..?? Possibly the grease that is in the aftermarket rebuild bearings is not up to the task. The generator will run pretty warm and could be cooking the grease out of the bearings if it is not the correct stuff. Aftermarket alternator rebuild parts are not know for being terribly robust....price is a key element and likely the grease is the cheapest stuff available. Try cleaning the bearings out and lubing them with something that will take some high temps like a synthetic grease or Krytox or somthing like that.