norteno

2006 C280 4matic. I've read all other posts here and elsewhere and have a slightly different scenario… I bypassed the AC unit with Duralast belt 910K6.... AC unit was noisy and going out and I did not want to pay the big bucks to have it replaced ....Then I replaced both grooved and smooth idler pullies, replaced belt tensioner assembly… and PS pump assembly... all was working well and then noticed slow but sure shredding of belt on the side towards the front of vehicle away from the motor until it eventually popped off. I tried to align pullies with Dayco laser tool using crank as a reference and the PS, ALT, and water pump pullies all lined up according to instructions and videos online. I then used strait edge to align idler pullies and they seemed fine within 1/2 rib. At about 2 weeks of driving, belt shredded again and popped off again all tore up. This time I noticed that the tensioner pully had some hard, black deposits on it on the rear, engine side of it so I scraped them off and smoothed it over with a file. I haven't been able to test it yet but do you guys have any ideas or suggestions??? Thanks!! ….another question, does the smooth idler pully (upper right side of engine) use a washer/spacer on it??? I don't remember as I have tried to install it with and with them and have always had the belt shred and pop off that I forgot whether factory specs call for washer or not.. Thanks for hearing me out on this long *** thread.