Hey guys, this is one of my first post on this forum so please forgive the ignorance. I have tried searching the threads but came up with nothing for my problem. so here it is: i have a 06 f150 xlt with a magnuson supercharger on it. last month i was on a business trip in Colorado when one of my idler pulleys froze up and actually fell off which ended up shredding the belt to pieces. I took had the truck towed to the only mechanic in this small town which was a Midas. They could not get a 6 rib 135" belt that would fit my setup nor could they find the right size idler pulley that had fallen off. The first day i spent there i trusted that they knew what they where doing but the second day i called them from my hotel and they told me they just could not figure it out. I have always done my own mechanics out of mere mistrust so i was very inquisitive. I suggested shaving an eight rib belt down to fit and throwing on a 82mm pulley, stretching a string through the system to figure the size of belt with the tensioner half strength and i would fix it when i got home. Three hours later she was done and i was so tired i just hoped in the truck, test drove it around the block then drove home. The truck did great but the next day i was looking over the bill and they had charged me for three pulleys? so i looked under the hood and sure enough they had changed ALL THE PULLEYS!! They did not give me back the original pulleys and when i called they said they had thrown them away and could not remember the sizes. I am now ready to replace the belt and pulleys but dont know the mm sizes of the pulleys. can any one help?

 

This may help........ I looked up mine on O'Reilly Auto Parts
2006 F-150 - Lariat - 5.4 gas


Belt Tensioner Assembly
• Pulley Diameter (mm): 76mm
• Pulley Width (mm): 30.5mm
http://www.oreillyauto.com/site/c/se...2006&make=Ford

I figure you can look up any others you may be interested in.

Hope this helps!!

 

And here's the Motorcraft idler pulley ...... but no specs:

YS253:
http://www.oreillyauto.com/site/c/de...3307&ppt=C0331


You will see 2 Gates idler pulleys here but the have slightly different widths and ODs:
http://www.oreillyauto.com/site/c/se...2006&make=Ford
(not sure which one works where)