If you're staring at a tangled mess of rubber under your hood, having a clear 2005 chrysler 300c 5.7 belt diagram handy is the only thing standing between you and a very long afternoon of frustration. It's one of those jobs that looks simple—it's just a belt, right?—until you take the old one off and realize there are about six different pulleys and you can't remember if the belt goes over or under that one idler in the middle.
The 5.7L Hemi is a legendary engine, but the way Chrysler packed it into the 300C engine bay doesn't leave a whole lot of elbow room. If your belt has started chirping like a distressed bird or, worse, snapped entirely while you were driving, you're probably looking at a DIY fix. Don't sweat it. Once you understand the flow of the routing, it's a pretty straightforward task.
Why you need a visual map
The serpentine belt on the 2005 300C 5.7 is responsible for powering pretty much everything that makes your car a car. It runs the alternator, the power steering pump, the air conditioning compressor, and the water pump. If the belt fails, you lose your battery charge, your steering gets incredibly heavy, and your engine will overheat in a matter of minutes.
The tricky part isn't just knowing where the belt goes; it's knowing which side of the belt touches which pulley. Most of the pulleys are "ribbed" to match the grooves on the belt, but the idler pulleys and the tensioner are usually smooth because they press against the backside of the belt. If you get this mixed up, you'll ruin a brand-new belt in about thirty seconds of engine runtime.
Identifying the pulleys in the 5.7 Hemi layout
Before you even try to loop the new belt on, you should get familiar with the players on the field. On the 2005 Chrysler 300C with the 5.7 V8, the layout is fairly vertical but spreads out across the front of the block.
Starting at the very bottom, you've got the Crankshaft Pulley. This is the big guy that provides the power. It's the "drive" pulley. Everything else is a "driven" pulley.
Moving up toward the top passenger side, you'll find the Alternator. It sits pretty high up, which is nice because it's easy to reach. Down below the alternator on the same side is the A/C Compressor.
In the center of the engine, you'll see the Water Pump Pulley. This one is crucial for keeping that Hemi from turning into a very expensive paperweight.
Over on the driver's side, you have the Power Steering Pump. And then, tucked into the gaps, you have the Idler Pulley and the Automatic Tensioner. The tensioner is the one you'll be wrestling with to get the belt on and off.
The actual routing path
If you're looking at the front of the engine, the path of the 2005 chrysler 300c 5.7 belt diagram follows a specific "S" curve pattern.
Typically, you start by looping the belt around the bottom of the Crankshaft Pulley. From there, you pull it up and over the Water Pump in the center. Then, it heads over to the Alternator at the top right.
After the alternator, the belt drops down to the A/C Compressor. From the A/C, it has to head back across toward the driver's side, going under the Tensioner Pulley. Finally, it wraps around the Power Steering Pump and then heads back to the crank.
I know, it sounds like a lot when you read it out loud. That's why people usually draw a quick sketch on a piece of cardboard before they pull the old belt off. If your belt is already gone, you're relying on your memory or a diagram like this one.
Tools of the trade
You don't need a massive toolbox for this, but having the right wrench makes a world of difference. To move the tensioner and release the pressure on the belt, you're going to need a 15mm wrench or socket.
Honestly, a standard 15mm socket and ratchet might be too thick to fit between the tensioner and the radiator fans. It's a tight squeeze in there. If you have a long-handled "serpentine belt tool," which is basically a very thin, flat bar with a socket attachment on the end, use it. It gives you way more leverage and saves your knuckles from getting smashed against the fan shroud.
How to actually swap the belt
First things first, make sure the engine is cool. You're going to be reaching deep into the bay, and those Hemi engines stay hot for a long time.
- Locate the tensioner. It's on the driver's side, halfway down the front of the engine. There is a bolt head right in the center of the pulley.
- Apply pressure. Put your 15mm wrench on that bolt and rotate it clockwise. This will compress the internal spring and move the pulley away from the belt.
- Slide the belt off. While holding the tensioner down with one hand, use your other hand to slip the belt off the topmost pulley (usually the alternator).
- Remove the old belt. Let the tensioner go back slowly—don't just let it snap—and then thread the old belt out through the fans.
- Check the pulleys. This is a pro tip: while the belt is off, give every pulley a spin by hand. They should spin smoothly. If you hear a grinding noise or feel "crunchiness," that pulley's bearing is shot, and putting a new belt on won't fix your noise.
- Route the new belt. Follow your 2005 chrysler 300c 5.7 belt diagram and loop the new belt around everything except the tensioner or the alternator. I usually leave the alternator for last because it's at the top and easy to reach.
- Final stretch. Crank that tensioner clockwise again, slide the belt over the final pulley, and make sure the ribs of the belt are seated perfectly in the grooves of the pulleys.
Troubleshooting common belt noises
Sometimes you put a brand-new belt on and the squealing doesn't stop. It's incredibly annoying. Usually, this happens for one of three reasons.
First, you might have a misaligned pulley. If the power steering pump or the alternator isn't bolted on perfectly straight, the belt will "chirp" as it tries to climb the side of the pulley.
Second, the tensioner itself might be weak. These are spring-loaded parts, and over twenty years, that spring loses its muscle. If the tensioner isn't pushing hard enough, the belt will slip under load—like when you turn on the A/C or turn the steering wheel all the way to one side.
Third, you might have fluid contamination. If your 300C has a small oil leak or a coolant leak that's dripping onto the belt, it's going to slip. No amount of "belt dressing" (which you should never use, by the way) will fix a belt that's soaked in oil. You've gotta fix the leak first.
Maintenance tips for the 300C
While you're under there, take a look at the belt every time you change your oil. You're looking for "glazing"—which is when the belt looks shiny and hard—or "chunking," where little pieces of the ribs are actually missing.
Modern EPDM belts (which is what your 2005 300C should be using) don't always crack like the old-school belts did. Instead, they just wear down thin, sort of like a tire tread. You can actually buy a cheap little plastic "belt wear gauge" that fits into the grooves to tell you if the belt is too thin to do its job.
Finishing the job
Once the belt is on, do a double-check. Look at the belt from the side to make sure it's not half-off any of the pulleys. If it's even one "rib" off, it'll shred itself the moment you turn the key.
When you're sure it's right, start the engine. Let it idle for a minute and watch the belt. It should run straight and true without any wobbling. If everything looks good, you've just saved yourself a $150 labor charge at the shop. The 2005 Chrysler 300C is a beast of a car, and keeping that 5.7 Hemi happy with a fresh belt is one of the best ways to keep it on the road for another 100,000 miles.
It's a satisfying feeling, honestly. You've conquered the maze of the 2005 chrysler 300c 5.7 belt diagram, your hands are probably a little greasy, but your car is quiet again. Now go grab a washcloth and a cold drink—you earned it.