PRODUCT DETAILS
Honda K20/K24 Top Cam Chain Guide - Genuine OEM (14540-PRB-A01)
Hearing a rattle or chatter from behind the timing cover on your K-series? Chasing weird cam angle corrections? Or just doing the smart thing and freshening up the timing components while you're in there? This is one of the first parts you should be looking at. Honda 14540-PRB-A01 is the genuine top cam chain guide, the upper guide that keeps your timing chain riding straight across the top of the head. When it wears out, the chain picks up slack, you get noise, and if you let it go far enough, the timing can skip and take the whole motor with it. For a part this cheap, that's not a gamble worth taking.
What This Guide Does And Why It Wears Out
Your K20 or K24 runs a timing chain instead of a belt, which is great, no belt interval to chase, but the chain still needs guides to keep it tracking right between the crank and the cams. This is the upper one, what Honda calls "Guide B, Cam Chain," and it spans the top of the timing assembly to keep the chain in line so your valve timing stays locked in, even when you're hanging on the limiter. People assume a chain setup is maintenance-free, but the guides are plastic riding against a moving chain in a hot, oily environment, so they wear, glaze, and eventually crack from heat, oil varnish, and constant contact. A worn guide is what's behind a lot of the chatter and timing weirdness people chase on these motors.
Replace It While You're In There
If you've got the valve cover off and the timing exposed, whether you're doing a chain, chasing a rattle, or building a motor on the stand, this is the moment to put a fresh guide in. Getting to it is the hard part, and the guide itself is cheap, so there's no reason to bolt everything back together over an old one that's already worn. Most people doing this job replace the guides, tensioner, and chain together while it's all apart, so you're not back in here in a year chasing a noise you could've knocked out today.
The Real Honda Part, Not A Copy
This is the genuine Honda guide, Japan-built and made to the exact width and profile your timing set needs, so it drops right in with no grinding, slotting, or guessing. There are no-name copies floating around for a few bucks less, but on a part that keeps your timing where it belongs at high RPM, the real one is the only one worth running. It's the same piece you'd get over the counter at the dealer, and it supersedes the older 14540-PNA-003. If you're building a K-swap or freshening a high-mile daily, it fits right, stays quiet, and doesn't do anything weird when you wind it out.
What You Get
- Genuine Honda top cam chain guide (14540-PRB-A01), also called "Guide B, Cam Chain"
- Upper timing chain guide for K20 and K24 engines
- Japan-built to factory width and profile, direct fit
- Supersedes part number 14540-PNA-003
- Keeps valve timing locked in, even at high RPM
- Sold individually
Fits These Cars
- 2002-2006 Acura RSX Base/Type S
- 2004-2007 Acura TSX
- 2002-2005 Honda Civic Si
- 2002-2006 Honda CR-V
- 2003-2007 Honda Accord
Note: Genuine Honda top cam chain guide, part number 14540-PRB-A01, also referred to as "Guide B, Cam Chain." This is the upper timing chain guide for K20 and K24 engines, Japan-built to factory width and profile for a direct fit. It keeps the timing chain tracking correctly so valve timing stays accurate, and a worn guide can cause chain noise, slack, and eventually skipped timing. Supersedes part number 14540-PNA-003. Best replaced alongside the timing chain and tensioner while the timing components are accessible. Sold individually. Fits the 2002-2006 Acura RSX Base/Type S, 2004-2007 Acura TSX, 2002-2005 Honda Civic Si, 2002-2006 Honda CR-V, and 2003-2007 Honda Accord. One guide per order.
Important Note
Part number 14540-PRB-A01 is only the top (upper) cam chain guide — the Honda Acura top cam guide sometimes called “Guide B, Cam Chain.”
It does not include the left or right side guides, the lower guide, the chain, or the tensioner. If you're trying to refresh every K24 cam guide genuine part or do a full K20/K24 timing job, you’ll need the other pieces as well.
Side guides are separate parts with their own numbers:
- Left side guide: 14520-PRB-A01 (different part from this upper guide)
- Right side guide: 14530-RZA-A01 or 14530-PNA-003 (depends on whether you’re running a K20 or K24)
If your vehicle has a K-series engine with over 100,000 miles, this Honda cam guide K20 / K24 Honda guide part is worth checking during routine valve adjustments or timing inspections.
Signs You Need to Replace the Top Cam Chain Guide
Timing chain guides don’t always fail in a dramatic way, but ignoring wear can lead to chain stretch, slack, or
jumping teeth, which can easily destroy a K20 or K24. Honda doesn’t give a hard mileage interval for the
Honda K20 top cam guide or K24 top chain guide, but watching cam chain
tensioner extension is key: replace the guide if the extension exceeds 13.5 mm, measured from the tensioner
body to the rod end.
- Rattling or Ticking Noises: Especially on cold starts or idle. Think diesel-like clatter from the timing cover area. That usually means a worn Honda cam chain guide causing slack.
- Check Engine Light with Timing Codes: P0011 or P0016 when the chain jumps a tooth or two, often with misfires or a rough idle once the engine’s warm.
- Poor Performance or Stalling: Noticeable loss of power, lazy VTEC engagement, hesitation on throttle, or even stalling at temp from bad timing.
- Visual Wear During Inspection: Cracks, grooves, or excessive play in the K24 cam guide genuine or K20 guide when you pull the valve cover or timing cover. Chain stretch (timing links not lining up at TDC) usually shows up with guide wear.
- High-Mileage Red Flags: 150,000+ miles on the original Honda 14540-PRB-A01, skipped oil changes, or mods like big cams or boost that load the chain harder than stock.