Routing the 2011 6.7L Cummins Serpentine Belt
The 2011 6.7L Cummins is the first year of theHPD (High Pressure Diesel) engine, so the belt routing is completely different from the 2007–2009 6.7L. If you're working off a diagram for an earlier year, you will install it wrong and waste an hour rethreading it. The belt is a single serpentine unit with an automatic tensioner. The part number stamped on most OEM belts is 53800014AB, which is 31.5 inches and has 6 ribs. Here's the routing, going clockwise as viewed from the front of the engine: Crankshaft pulley (bottom center) — the belt wraps under this one, entering from the right side.
Power steering pump pulley (lower left) — belt runs from the crank up and around the outside of the PS pump. Water pump pulley (mid-left) — straight up from the PS pump, the belt goes around the water pump. Note that the water pump on this engine is actually gear-driven from the front of the block, but there's still a pulley that the serpentine belt contacts for accessory drive reference. Don't confuse the two systems. Alternator pulley (upper left) — continues up to the alternator, routing around the outside.
A/C compressor pulley (upper right) — across the top, the belt wraps around the A/C compressor. This is the large pulley on the passenger side of the engine bay. The A/C compressor is a variable displacement unit, so there's no clutch pulley to deal with — just the main pulley. Idler / tensioner assembly (center-right) — the belt drops down to the tensioner arm. The tensioner is a spring-loaded automatic unit with a smooth pulley. This is where most people get stuck because the tensioner needs to be compressed to relieve belt tension during installation or removal. From the tensioner, the belt goes back down to the crankshaft to complete the loop.
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The tricky part is getting the tensioner to hold while you snake the belt onto the last pulley. I spent about twenty minutes fighting a stuck tensioner on a '12 that had been sitting for three years. The pivot point had corroded enough that the spring couldn't move freely. What actually worked was spraying PB Blaster on the tensioner arm pivot, letting it soak for ten minutes, then using a 3/8" drive ratchet with a deep socket on the tensioner bolt head to slowly compress it. The factory tool for this is Mopar #C4121 or an equivalent serpentine tool, but a long-handled ratchet gives you more leverage and better control over the release speed. Rushing it will snap the belt or bounce the tensioner arm and make you start over. When you're routing it yourself, don't try to memorize the entire path at once. Start with the crank and the tensioner already compressed, drop the belt onto the A/C compressor pulley first since it's the tightest fit, then work your way around counter-clockwise until you can let the tensioner ease back and grab the final run. If you've got the belt on every pulley except the crank, you missed a step somewhere. One thing the diagrams don't always show clearly: there's a small idler pulley located between the alternator and the A/C compressor on some applications. It's easy to overlook because it's tucked against the bracket. If your belt path doesn't match the picture you're looking at, check for that one. On the 2011 specifically, it's there and it changes the effective wrap angle on the A/C compressor pulley.
After the belt is on, turn the engine over by hand two full revolutions with a socket on the crank bolt before starting it. This seats the belt properly on every pulley and confirms you didn't route it backwards or miss a groove. The 6.7L is an interference engine, so if something binds during this check, stop immediately and trace the path again rather than cranking it. If you need to verify your routing against an official diagram, search for "2011 67 Cummins Belt Diagram" and look for the one that shows the HPD engine block with the belt running under the crank pulley. Most of the images that come up are for the 2007–2010 LTG engine and will mislead you. The HPD engine has a different accessory layout, particularly the position of the power steering pump and the water pump pulley, so cross-reference with the part number on your existing belt whenever possible.
