Belt squeals and wears the inside rib off

[1$Chuck]

My 1990 dodge's belt squeals all the time and I just replaced both the belt and the tensioner. The previous belt had the inside rib completely worn off of it and the new one is starting to do the same thing. I believe that the noise is coming from the alternator pulley and that is where I'm seeing a built up do black belt particles. It appears to me that the alternator is pointed a little downhill as compared to the water pump pulley, which would make sense with the wear in seeing. My question is how do I fix this? It appears that the alternator mounting brackets is part of the lower coolant line. Is there enough slop in that bracket to rotate it a few degrees to align the alternator?

[CAJUN 93]

my d350 started doing that. it would jump a rib on the belt to the back side and then cut it off, spreading little strips of belt all over the engine compartment. It would do it pretty quick after installing the new belt. I fixed it when I found the fan support had moved forward in relation to the bearing. got it set right and haven't had a problem since.

Daryl

[1$Chuck]

Cajun,
Could you elaborate a little more on the fan support problem you had?

[Horicon93]

I had the same problem. As soon as I'd start the engine, the belt would jump 1 rib on the alt pulley. After a new fan hub bearing and idler, I discovered that my water pump was shot. There was enough radial movement at the pulley to cause the belt to slip by 1 groove. There was no leakage from the pump at all ! Replaced the pump, and the belt again, problem solved.

[1$Chuck]

Yeah, I recently replaced my water pump, but that didn't fix the problem. In fact i think it might even squeal more.

[9312v]

Is your tensioner new? I had a similar problem and it was the tensioner twisting enough to let the belt eat into the arm.

[CAJUN 93]

Sorry I didn't catch this earlier. What happened to mine was the bearing in the fan mount moved forward just a fraction of an inch and it caused the belt to walk off the back of t
he fan pulley one rib at a time. If you looked down the drivers side of the fan mount from above you could see it was not quite lined up with the crank pulley. I removed the mount and pressed the bearing back in just a little bit and have not thrown a belt since, over 80k miles. I don't know why it moved and it hasn't done it again but I still find little shreds of belt when I clean the engine compartment.

Daryl.

[CAJUN 93]

I guess I need to clarify that. I find shreds of the 5 or 6 belts it ate while I was trying to figure out what was going on. It hasn't eaten a belt again. You can remove the fan and shroud without removing the belt and pulleys and run the engine while watching the pulleys for movement without fear of getting you hand/clothes in the fan. Rev the engine and snap the throttle back and forth while watching what's going on and it will show you why it's mad.

Daryl

[1$Chuck]

Thanks for the clarification. Mine is still making noise. My tentioner is pretty new, probably less than 8k miles. It was the first thing I replaced in my quest to stop the squealing. I'll investigate farther.