Whining noise while running
 

I have a 2000 Blazer, 2WD with 255,000 miles. Been a great vehicle. Lately though I am hearing a whining noise in the engine similar to power steering pump failure. Replaced power steering pump which seems to have remedied some of this but now I still have whinning while in reverse and drive, no whining in netueral or park. Seems more noticable at lower rpm's. Thinking tourque convertor or front tranny pump. Has anyone else had this problem or can assist me with diag in this situation.
Thank you in advance.

Yep. I had that problem for about the last 30k miles. I replaced filter and serviced tranny with no luck. Friday coming home from work the tranny strated slipping in OD. Yesterday the tranny went out - it would miss gears, over rev, and eventually would only crawl when pressing the accelerator but tacking high. I am swapping the tranny out over the next couple of days.

So, I just noticed this was 3/18/12 not 3/18/13.

Just to finish this up, for the symptoms originally listed, it is the torque converter main bearing that is the problem. It goes and pukes metal into the transmission, killing it. Been there done that with our Blazer.