For Mercedes-Benz 560 owners and automotive enthusiasts considering a DIY approach to timing chain guide replacement, this guide provides a detailed walkthrough of the process. It’s crucial to understand upfront that while DIY is possible, this is a complex task best suited for individuals with a solid foundation in automotive mechanics. Incorrect procedures can lead to significant engine damage and costly repairs. This guide focuses on replacing the upper timing chain guides, a common maintenance point in the Mercedes Benz 560 series, offering insights and steps to navigate this intricate procedure.
Image: Example of a fractured timing chain guide from a Mercedes Benz 560 engine, highlighting the importance of timely replacement to prevent engine damage.
The image above illustrates a fractured timing chain guide, specifically from the passenger side inboard position of a Mercedes Benz 560 engine. It’s important to note that these guides are designed to be stationary components. The fracture shown is centrally located and underscores the potential for failure within these parts. As you continue reading, you’ll gain a deeper understanding of the implications of such fractures and how to address them. In many instances, when the upper section of a guide breaks and falls into the path of the timing chain, it can cause engine interference, often resulting in bent valves.
Beyond the three cylinder head guides and the tensioner guide, Mercedes Benz 560 engines also incorporate two additional nylon guides located lower down, behind the timing cover, along with another tensioner guide for the oil pump’s separate chain drive. Due to their location and the extensive labor required to access them, these lower guides are frequently addressed only during a complete engine overhaul. While these lower guides are generally less prone to issues compared to their upper counterparts, their condition should not be disregarded. The decision to replace them often hinges on balancing the immediate repair needs with the long-term engine maintenance strategy. Opting to remove the cylinder heads can significantly simplify the re-installation of the timing cover if you choose to replace the lower, block-mounted guides at the same time.
Consequently, a common approach is to replace the three upper cylinder head guides, the tensioner guide, the tensioner itself, and the timing chain. For this critical repair, utilizing genuine OE Mercedes-Benz parts or components approved by reputable suppliers like Peach Parts or Pelican Parts is strongly recommended. While aftermarket options exist, the reliability and longevity of OE parts are paramount for the engine’s health and performance.
This repair demonstration focuses on a 1989 Mercedes Benz 560 SL, but the procedure remains largely consistent across all 560 models, with minor variations in engine attachments. Although the intake manifold is shown removed in some accompanying photos, this is not a mandatory step for timing chain guide replacement and was done on this particular vehicle to address unrelated seal maintenance.
The subsequent photographic steps begin assuming that the valve covers, power steering pump and its bracket, and the alternator and its bracket have already been removed. Often, the power steering pump and alternator can be carefully set aside without complete disconnection, streamlining the process.
Image: Aligning timing marks on the camshaft of a Mercedes Benz 560 engine, driver’s side, crucial for accurate timing chain guide replacement.
In the image above, the process of aligning the timing marks and marking the position on the driver’s side of the Mercedes Benz 560 engine is depicted. You can observe the small alignment marks at the center of the camshaft, indicating proper positioning.
Image: Passenger side camshaft timing marks alignment on a Mercedes Benz 560 engine, ensuring synchronization for timing chain service.
This photo demonstrates the timing mark alignment on the passenger side camshaft of the Mercedes Benz 560 engine, mirroring the driver’s side to ensure correct engine timing.
Image: Mercedes Benz 560 engine set to Top Dead Center (TDC) position, a critical step before timing chain guide replacement.
This image illustrates the engine set to Top Dead Center (TDC). For solo mechanics, using tie-wraps to secure the chain and sprocket is a helpful technique during removal. This also aids when using an impact wrench to loosen the central camshaft bolt. Exercise caution to prevent components from falling into the engine.
Image: Driver’s side camshaft of a Mercedes Benz 560 marked and secured before camshaft sprocket bolt removal, preventing timing misalignment.
The driver’s side camshaft is shown marked and secured in this image, prepared for camshaft sprocket bolt removal. This step is crucial to maintain timing integrity during the process.
Image: Crankshaft timing marks on a Mercedes Benz 560 engine, aligned at the zero position for accurate timing verification.
This photo highlights the crankshaft timing marks, correctly aligned to the zero position. It’s also vital to confirm that the ignition distributor rotor is pointing to the #1 cylinder position. With the crankshaft at zero, distributor rotor at #1, and camshaft marks aligned, the engine is correctly positioned to commence the timing chain guide replacement.
Image: Loosening the camshaft bolt on a Mercedes Benz 560 using an impact wrench, a step in disassembling the timing mechanism.
Employing an impact wrench for a brief burst to loosen the camshaft bolt is shown here. Securing the camshaft with channel locks is advisable, utilizing the central nubs while being mindful of the camshaft oiling tube and its delicate plastic clips. Once loosened, the bolt should unthread by hand. Set the bolt aside and suspend a wire from the hood to hold the timing chain, ensuring enough slack to manipulate the chain. Gently tap the sprocket’s backside using the wooden end of a hammer, being careful around the timing chain. Avoid using the steel hammer end or rubber mallets, which can shed debris. A few taps should initiate movement. Wiggle and pull the sprocket towards you, keeping the chain in mind.
Image: Removing the camshaft sprocket from a Mercedes Benz 560 engine while securing the timing chain to prevent it from falling into the engine.
As the camshaft sprocket is removed, ensure the timing chain is held aloft to prevent it from falling into the engine. The chain must remain taut. Utilize the wire to suspend it while proceeding with guide replacement.
Image: Close-up on the washer behind the camshaft sprocket of a Mercedes Benz 560, highlighting a small part that needs careful handling.
Pay close attention to the washer as shown; it’s crucial to prevent it from falling into the engine. Reinstall the bolt temporarily to secure the sprocket and prevent washer loss.
Image: Camshaft bolt hand-tightened on a Mercedes Benz 560 engine, securing the sprocket and washer to prevent parts from falling into the engine.
Here, the bolt is hand-tightened to keep the sprocket and camshaft washer/timing mark in place, preventing accidental drops into the engine.
Image: Using a makeshift pin puller tool for removing timing chain guide pins on a Mercedes Benz 560 engine, demonstrating a DIY approach.
Removing the guides becomes easier with experience. While specialized tools exist, a DIY pin puller can be fashioned using valve cover bolts, a socket, and washers. If DIY tools are not preferred, purchasing a dedicated puller is recommended. When using a DIY puller, exercise extreme caution to avoid jamming the pin during removal, especially in uneven areas. Gaps may need filling to ensure even pulling. Stripping or bending pins is possible, even with specialized tools, if care is not taken. Stripping can occur if threads are pulled due to insufficient clearance. In such cases, a high-quality steel screw and pry bar can assist, but a pin replacement will be necessary.
Image: Timing chain guide pin partially removed from a Mercedes Benz 560 engine, showing progress in the guide replacement process.
This image shows a pin partially extracted. From this point, the pin should be removable by hand.
Image: The last pin being removed from the timing chain guide on a Mercedes Benz 560 engine, requiring support to prevent the guide from falling into the engine.
This pin shown is the final one securing the guide. Ensure the guide is supported to prevent it from falling into the engine once this pin is fully removed.
Image: Side-by-side comparison of an old and a new Mercedes-Benz timing chain guide, highlighting material degradation over time.
A side-by-side comparison of an old guide and a new, genuine Mercedes-Benz guide. The age-related brittleness of the old part becomes evident when compared to the new component.
Image: Installing a new timing chain guide into a Mercedes Benz 560 engine, aligning pin holes for proper fitment.
Slide the new guide into position and push the pins through, aligning the guide holes with those in the head. Light tapping may be needed to overcome plastic resistance, but ensure it’s gentle. Confirm pins are slightly within bores after clearing the guide before driving them fully in. Sealant application at the ends is required to prevent oil seepage, as shown in the next image.
Image: Applying sealant to the timing chain guide pin on a Mercedes Benz 560 engine, crucial for preventing oil leaks after replacement.
Key Takeaways for Mercedes Benz 560 Timing Chain Guide Replacement:
- Use OE Parts: Always opt for Original Equipment Mercedes-Benz parts or approved equivalents to ensure compatibility and longevity.
- Precision is Key: Accurate timing mark alignment and careful handling of components are essential to prevent engine damage.
- DIY Caution: This task is complex and requires mechanical expertise. If you are not confident in your abilities, seek professional assistance.
- Inspect All Guides: While this guide focuses on upper guides, consider the condition of lower guides for comprehensive engine maintenance.
Replacing the timing chain guides on a Mercedes Benz 560 is a significant maintenance task that, when done correctly, can extend the life and performance of your engine. By following these steps and prioritizing precision and quality parts, you can successfully complete this repair. However, always prioritize safety and consult professional resources if you encounter challenges or are unsure about any step in the process.
