RV Repair: alternater belts, crankshaft pulley, smog pumps

Question

-if the pulleys are not aligned properly how do you adjust-or do you replace them cause they are bent-----------------------

Followup To

Question -
I have 1987 fl4eetwood jamboree 26' motorhome, ford chassis w/ 460 v-8 it eats alternater belts, it appears to be a bad design although I am not sure,there is a small alt. belt from  crankshaft pulley to alt., then another belt from alt. driving two smog pumps directly above the alt.. I have tried everything including replacing alt. with no success. I tighten the belt properly and it work fine for a couple hundred miles or less , then starts squealing ,and eventually goes out. Have you seen this and can you help?

Answer -
I have seen this before, however, it takes some doing to check.  take a long straight edge and place it on the pulleys that are giving you the problem.  you will need to go from one side of one pulley to the other side, then to the other pulley that the belt rides on.  Make sure the pulley is flat on the straight edge and the pulleys align properly.  This will tell you if they are slightly out.

Answer
If the pulleys are not aligned properly, and they are not bent, you will need to place shims or washers in strategic places to help move the pulleys in the proper location.  someone down the line has probably worked on the engine and didn't bother to re-align or notice that there were washers under certain areas