Dodgeoilburner

The problem all started when i noticed this clacking sound and found the belt tensioner jumping quite a bit. I let it go until the belt started fraying and assumed the tensioner was the problem. I put a different one on (that i had never had any problems with) and the belt again tracked towards the engine and frayed. The alternator is new and seems fine. The A/C compressor seems alright but there is a little play in the pulley. Anyone have this problem? I'd hate to buy a new tensioner or a compressor and not fix the problem.

patdaly

Make sure your Fan support bearing isn't going..... Might also want to inspect the balancer rubber, and WP pulley.

Dodgeoilburner

So i had another look, and both tensioners i have don't look lined up when installed. I put a shim behind it to straighten it out and everything is tracking well. I'm thinking the tensioner is the problem but what are the chances that the tensioner i had on my old engine, that worked fine, is bad as well as the one that was on my engine? I hate being fooled!

kujo

Count the grooves in your new alternator pulley. Mine was eating belts when I bought it and the previous owner had installed a new alternator before I got it. Turns out there were 6,7 and 8 rib pulleys on the same alternators but for different engines. Mine had a 7 rib pulley but the cummins trucks have an 8 rib belt so it was forcing the belt to ride up on the pulley. Fixed it and the belt still looks like new. I did have a hard time finding a pulley though

Dodgeoilburner

Actually the alternator i got came with a double v-belt pulley, i had to put the one off my old one on. I'm going to try a new tensioner, i hope they aren't too pricey.

kujo

was it eating belts before the new alternator? its worth the time to count the grooves in everything just in case.. i know i wasnt the only one around here with the same problem.. if your alternator was changed before it still could have the wrong pulley on the last one.. when i went to carquest here to swap pulleys with them the alternator they had also had the wrong pulley installed so its pretty common.

i was also told before i found my issue that the tensioner pulley can wear on a slope causing the belt to try to ride off the end forcing it against the other pulleys.. other than that im stumped

jdjanetka

I had a similar problem when I put a new tensioner on and it refused to track right running the belt a rib off. It ended up being corrosion on the mounting surface that the tensioner sits against. Wasn't much but once cleaned it tracked nice and straight.

9812vram

If You had to shim that tensioner to make it "look straight" then that's your problem. Those tensioners also wear at the spring pivot point which will cause it to run crooked. It's deffinitely possible both tensioners are worn like that. You can usually see this if you hold it up and look at it from the side.