Lexus Repair: 1994 Lexus LS400, lexus ls400, power steering pump

Question
QUESTION: The serpentine belt keeps riding off the bottom pulley and after a period of time it slices off about an 1/8" of the belts width. I have replaced the belt tensioner, and the power steering pump complete. Still having the same problem. I haven't notice any of the pulleys being out of alignment. One thing that I have observed is that the engine seems to change tunes as if its converting from a V8 to a V6 firing order and that is when the belt starts to ride off pulley. Is this a possible cause and if so, how can I correct it?

ANSWER: IT LOOKS LIKE I MAY NEED A LITTLE MORE INFO. WHICH SIDE OF THE BELT STARTS TEARING UP? THE INNER OR THE OUTER? IF ITS THE INNER, YOU MAY WANT TO LOOK IN THE DRIVERS SIDE CAM SENSOR AREA. IF THE T-BELT HAS RECENTLY BEEN DONE, SOMETIMES THE HARNESS AND OR RETAINER TOUCHES THE
INSIDE OF THE DRIVE BELT. I WOULD CLOSELY CHECK ALL PULLEYS ON THE OUTER EDGES TO SEE IF ANY DAMAGE IS EVIDENT. ALSO JUST A SIDE NOTE. YOU MAY HAVE ANOTHER CONCERN. LEXUS V-8 MOTORS DO NOT SWITCH FROM 8 CYLINDER TO 6 CYLINDER.AND LAST, THIS MAY BE A STRETCH BUT CHECK THE CRANKSHAFT END PLAY. .0015 IS MAX. ALSO YOU MAY WANT TO CHECK ALL DRIVEN COMPONENTS FOR EXCESSIVE END PLAY. THE POWERSTEERING PUMP WILL HAVE THE MOST, WHICH IS NORMAL. BESIDES YOU HAVE ALREADY REPLACED THE PUMP ASSY.GOODLUCK


---------- FOLLOW-UP ----------

QUESTION: The belt is tearing up on the outer side (towards radiator). We have had the time belt replaced about 6 months to one year. Didn't have a problem then.

Answer
WELL, SHORT OF LOOKING AT IT MYSELF, I HAVE SEEN WHERE THE P/S PULLEY GETS BENT CAUSING THE OUTER RIB OF THE PULLEY TO MOVE IN TOWARD THE MIDDLE OF THE BELT EVERY REVOLUTION OF THE PULLEY.ALSO YOU MIGHT CHECK THE AXEL MOVEMENT OF THE A/C PULLEY. THIS COULD CAUSE IT ALSO.THATS ABOUT ALL I HAVE. SOMETHING IS MAKING CONTACT WITH THE BELT WHERE IT SHOULD'NT.