Timing Sprocket Kit

Introduction

Thank you for purchasing our repair kit for your Mercedes M271 timing sprockets.

Great care has been taken to ensure that this kit is of the highest quality to ensure the performance and reliability of your engine. This repair kit has been precision manufactured using the best quality Austrian high tensile steel, surface hardened to ensure toughness, long life, and a low friction coefficient.

For optimum results, it is vitally important that the condition of the crankshaft drive sprocket on your engine is in good condition and that the chain and chain tensioner/wear strips be replaced.

In order to be sure that you will be completely satisfied with your purchase, please read the following instructions carefully and confirm that you have received the following SIX items:

• 1 Instruction manual.
• 1 Sprocket “A” Outer.
• 1 Sprocket “E” Outer.
• 1 Loctite Thread Locker.
• 1 Torx Bit "T30".
• (Implicit 6th item is the kit itself or the manual, as 5 physical items + manual are listed).

Tools Required

You will need the following items to strip, clean, and assemble this product:

• Small circlip pliers
• Small socket set
• Small torque wrench
• Suitable brush
• Solvent for cleaning (e.g., lacquer thinners or engine cleaner)
• Clean cloth

Caution and Safety Instructions

⚠️ CAUTION

The refurbishment of the timing sprockets should only be attempted by technically competent persons.

Please note when cleaning parts with hazardous chemicals or solvents, please follow the relevant safety instructions as indicated by the chemical or solvent supplier.

1. Work in a clean, well-ventilated area.
2. Avoid skin contact with solvents or chemicals.
3. Ensure there are no naked flames or ignition sources nearby.
4. Care should be taken when working with hand tools to avoid injury.

? STOP: If you feel the need to use hammers on any of the following steps, you are doing something wrong! ??️

Stripping Original Sprockets

Follow these steps to carefully disassemble the original sprockets:

1. On the side of the original sprockets, remove the two circlips that hold the retaining washer, spring, and plunger. The original circlips may be discarded. Carefully remove the retaining washer, spring, and plunger. Please note that sprocket “E” has a short plunger and sprocket “A” has a long plunger; the springs and retaining washers are the same.

   Image Description: A visual guide showing the removal of circlips and internal components (washer, spring, plunger) from a sprocket. A second image shows the disassembled components laid out.

2. Using the ¼ inch drive Torx Bit supplied, remove the bolts that hold the sprocket caps. Clean excess old engine oil off end caps and bolts, taking care not to damage the end cap working surfaces. Please note that sprocket “E” has smaller diameter caps and sprocket “A” has larger diameter caps. The bolts are all the same.

   Image Description: A sequence showing the removal of four bolts securing the sprocket cap using a Torx bit. The image highlights the difference in size between the caps for sprocket "A" (larger) and sprocket "E" (smaller).

3. Remove 4 springs from Sprocket “A” and clean off excess old engine oil.

   Image Description: A visual showing the removal of four springs from the internal mechanism of Sprocket "A".

4. Carefully remove the centre core of each sprocket and clean off excess old engine oil.

   Image Description: A rendering of a sprocket's central core component, which is then shown removed and cleaned.

5. Clean all parts properly with a suitable non-corrosive solvent. PLEASE FOLLOW SOLVENT SAFETY INSTRUCTIONS.

6. The original sprocket outers may be discarded. Please do so taking into account the environment, by making sure that there is no excess oil discarded with them.

Preparing for Assembly

Using a brush, suitable cloth, and solvent, carefully clean all parts, removing all build-up of old engine oil. Take special care when cleaning the ends of the bolts and the threaded side of the sprocket caps, as when you assemble, you will be using Loctite thread locker and you will need clean surfaces for the Loctite to stick.

Inspect both cores for cracks. If the core is cracked (very rare), the repair cannot be completed using this kit. Please contact your supplier for options.

Parts List: Clean and Ready for Assembly

Remove new sprockets from packaging and make sure that they are clean.

You should now have the following parts clean and ready to assemble:

Parts List (Continued)

Preparation of New Sprockets

Separate the parts into the parts for the sprocket “A” and the parts for the sprocket “E”.

Sprocket “A” is the sprocket with the slightly larger hub, 84mm, and has place for the four springs removed earlier.

1. The internal core has place for the four springs removed earlier.
2. The one sprocket cap is clearly marked “A” and its partner is the same diameter.
3. The retaining washers are the same.
4. The plunger is the LONGER of the two.
5. The plunger springs are both the same.
6. The four larger springs are for this sprocket.
7. The four Torx head bolts are the same.

Sprocket “E” is the sprocket with the slightly smaller hub, 78mm. It does NOT have place for the four springs.

8. The internal core does NOT have place for the springs to locate.
9. The one sprocket cap is clearly marked “E” and its partner is the same diameter.
10. The retaining washers are the same.
11. The plunger is the SHORTER of the two.
12. The plunger springs are the same.
13. The four Torx head bolts are the same.

Greasing Instructions

Using the grease supplied, lightly grease the inside of the new sprockets. Make sure to grease the bore where the retaining washer, spring, and plunger will need to go back. You will notice that the new circlips have already been installed. Try not to get excess grease in the holes where the bolts will be going through, as this may cause a problem with the Loctite thread locker later.

Lightly grease the internal cores as well as the sprockets caps. Take care not to get excess grease in the threads of the sprocket caps.

Lightly grease the retaining washer and plunger.

Assembly of New Sprockets

Assembly for Sprocket "A"

Starting with sprocket “A”:

1. Replace the retaining washer up against the circlip from the inside. Do not remove the circlip. The retaining washer can be replaced from the inside of the sprocket. Once the retaining washer is in place, the spring and the plunger can be replaced.

2. While holding the plunger against the spring with your finger, select the already prepared inner core “A”. Note that on the side of the inner core there is a 10mm pocket for the plunger to locate. This hole needs to line up and locate with the plunger.

   Image Description: A visual showing the inner core "A" with a red arrow pointing to the 10mm pocket designed for the plunger's location.

3. Press the plunger in against the spring all the way with your finger; it should move in and out freely. With the inner core properly aligned, insert the inner core. If the inner core is properly aligned, you should hear and feel the plunger locate into the 10mm pocket with a clicking sound. You will now not be able to remove the inner core anymore.

4. Replace the four springs into the sprocket core and outer sprocket, making sure they locate correctly.

5. Replace the sprocket caps. You will notice the inner core has a 6mm locating pin sticking out approximately 5mm. The core with the threads fits on this side of the assembly. The cap that is clearly marked “A” fits on the other side.

6. Carefully make sure that there is no excess grease in the holes or the threads. If there is, carefully wipe it out with some solvent and a cloth.

7. Carefully place a small amount (one to two drops per bolt) of Loctite Thread Locker on the ends of the four bolts. Loctite Thread Locker sets in 20 minutes and cures fully in 24 hours. This means that you have to work quite quickly once you start to screw the bolts in. Screw the bolts in, avoiding any contact with excess grease. Using the Torx bit supplied and a Torque wrench, tighten the bolts all to 14 Nm.

Assembly for Sprocket "E"

7. Similarly with sprocket “E”, replace the retaining washer up against the circlip from the inside. Do not remove the circlip. The retaining washer can be replaced from the inside of the sprocket. Once the retaining washer is in place, the spring and the plunger can be replaced.

8. While holding the plunger against the spring with your finger, select the already prepared inner core “E”. Note that on the side of the inner core there is a 10mm pocket for the plunger to locate. This hole needs to line up and locate with the plunger.

   Image Description: A visual showing the inner core "E" with a red arrow pointing to the 10mm pocket designed for the plunger's location.

9. Press the plunger in against the spring all the way with your finger; it should move in and out freely. With the inner core properly aligned, insert the inner core. If the inner core is properly aligned, you should hear and feel the plunger locate into the 10mm pocket with a clicking sound. You will now not be able to remove the inner core anymore.

10. Replace the sprocket caps. You will notice the inner core has a 6mm locating pin sticking out approximately 5mm. The cap with the threads fits on this side of the assembly. The cap that is clearly marked “E” fits on the other side.

11. Carefully make sure that there is no excess grease in the holes or the threads. If there is, carefully wipe it out with some solvent and a cloth.

12. Carefully place a small amount (one to two drops per bolt) of Loctite Thread Locker on the ends of the four bolts. Loctite Thread Locker sets in 20 minutes and cures fully in 24 hours. This means that you have to work quite quickly once you start to screw the bolts in. Screw the bolts in, avoiding any contact with excess grease. Using the Torx bit supplied and a Torque wrench, tighten the bolts all to 14 Nm.

Completion and Important Notes

Congratulations, you are now finished assembling the Timing Sprockets for the Mercedes M271 engine.

PLEASE NOTE:

Our sprockets have a small diameter 3mm hole just below the teeth. This hole is for manufacturing purposes only and not a timing reference.

The timing mark for assembly of the engine is marked on the side in red ?.