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Post Info TOPIC: Timing Chain Installation + Guides 560 / 420 Mercedes Benz V8 M117 / M116


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Timing Chain Installation + Guides 560 / 420 Mercedes Benz V8 M117 / M116


In this write up I will be covering the timing chain install along with the upper guides. This is a relatively complex job so DIY'ers may want to really take their time. Use this information at your own risk. In other words, this is not an easy or quick job and will take several hours to complete. If you are not using special tools for this job an extra pair of hands will be needed.

FYI - If you are planning on just installing the upper timing chain guides you should check out this thread here -

http://autotrend.activeboard.com/t43370876/mercedes-benz-560-engine-timing-chain-guide-replacement-phot/

The thread above will be more specific to just installing guides. It is important to remember that removal of the followers is not necessary if you just plan on replacing the guides, however if you are a rookie DIY'er it may be best to remove the followers to eliminate the possibility of re-coil on the passengers side camshaft when re-installing the chain and sprocket.

Now this thread picks up assuming you have already removed the valve covers, alternator, fan, belts, power steering pump and the spark plugs. I always start by installing the new guides prior to installing the chain because often times the old guides are very brittle if not broken when the job comes in. Installing the guides first ensures you do not have any of the old guides break or cause problems while rolling in the new chain.

The first step after all of the parts above have been removed is to take out all of the camshaft followers. To get information about how to remove the followers see this link-

http://autotrend.activeboard.com/forum.spark?aBID=91042&p=3&topicID=52276366

Once the followers have been removed as per the link above, you will then want to set the engine to TDC or "Top Dead Center". Do this by rotating the lower crankshaft pulley until the needle points to "0" (Zero) as shown in the photo below. This may or may not be TDC as the crank spins twice to every revolution of the cam.

In this photo above you can see the lower crank pulley is pointing to "0" (Zero). The next step to ensure the engine is at TDC is to either check the position of the distributor rotor (should be pointing to #1 cylinder)

Here you can see the hash mark in the center of the rotor matches that of the one on the distributor housing. I have marked the rotor with green paint for you to see, so it is not necessary for you to mark the rotor as the hash marks should be obvious. If the engine is 180 degrees off the rotor will be pointing in the opposite direction, simply turn the engine over one more revolution until its back at zero again and the rotor should be pointing to #1.

Now it's time to check your camshaft marks. The right and left camshaft will have markings like the one above. If the balancer is at Zero, and the distributor points to #1 then both left and right camshaft marks should align as shown in the photos above. If this is the case you are now at TDC. Remove the timing chain tensioner located on the right passengers side head held on by 13mm bolts. This will allow the slack needed for installation of the new guides.

I like to use a paint marker to mark my timing chain once the engine is at TDC. This helps to ease re-assiblily since it's often hard to see the marks on the back of the cam sprocket. It also helps to mark the "left" and "right" just incase. When finished we will use carb cleaner and a rag to remove the marks.

Now it is time to remove the center bolt on the left driver side camshaft sprocket. Using an impact really helps but if you dont have one grab a pair of locking pliers and hold the camshaft (Not on the lobes!) while you bust it loose. With a rubber hammer tap on the back side of the camshaft sprocket until you can wiggle it off. Carefully remove the sprocket while keeping the chain taught. Use some mechanics wire to keep the chain up (do not let it fall in the engine) and out of the way. Now it is time to remove the outboard guide rail. Do this by removing the pins that hold it in.

In the photo above you can see a special tool being used to remove the timing chain guide rod pin. You can also make a home-brew tool out of your valve cover bolt, some washers and a small deep well socket. Remove both pins but be sure to be holding the rail so it does not slide into the engine.

Here you can see the left drivers side outboard timing chain guide rail removed.

Here you can see the left outboard rails side by side New vs. Old. Note the color, as every time I see them break they are usually that off color orange. This suggest they have become brittle and are in need of replacement.

Here the left inboard rail has been installed. Be sure to use a sealant on the pins when re-installing to prevent oil leaks.

You can see in the photo above that both upper guides on the left cylinder head are in place and the pins have been installed and sealed.

And yet another look.

Here you can see Old vs. New on the left inboard rail, which just happens to be the same part number as the right hand side inboard (FYI).

And here is the backside of the left inboard guide. Now it's time to put the sprocket back on the chain and re-install. Do not fully tighten the sprocket bolt at this time, however run it down hand tight. This is when your little paint pen art comes in handy.

Here you can see the new inboard and outboard upper guides installed along with the sprocket. Your marks should be exactly where they were (TDC) if you did things right.

Now it's time to remove the right passengers side sprocket, doing pretty much the same as you did on the left drivers side. Once the sprocket is removed and out of the way, with the chain held up with mechanics wire you will see the right side tensioner rail, which is shaped like a banana.

Above you can see the old tensioner guide. You remove it by taking out the 5mm plug on the timing cover and using a magnet to pull the pin while holding on to the guide. Sometimes the pin requires the use of an easy out to remove. Careful there is a washer on that plug you dont want to lose.

Here you can see the SERIOUS damage old brittle guides cause. This guide has worn clean thru and is now grinding on the aluminum shoe! This not good, and will now require us to remove the oil pan to fetch the chunks. While I often times see the left inboard guide kill these engines, it's quite clear the tensioner guides can be fatal as well if left too long.

In the photo above I have installed a new tensioner guide to the shoe. Look much better. Installation is basically the reverse of removal. Clean everything up nice.

In the photo above I have completed installing the timing chain tensioner guide, the right passengers side inboard guide and the chain and sprocket. Just like the other side everything should line right up and the engine should still be at TDC.

Now it's time to roll in the new timing chain. They make a tool for this, but to date I just have an extra pair of hands around and feed it by hand.

This is a factory OE chain, about the best you can buy. It also includes a master link, which if used properly is a safe way to link the chains. Be sure to buy TWO master links, the reason I will explain later. Also, I have seen on other forums people talking about soaking the chain, I am here to say that will make for a big mess along with hinder the installation of the chain. You can lube the chain AFTER it's installed. (FYI)

 

You must now decide what link to remove. I usually roll the chain in on the left drivers side sprocket, so that is where I remove my link. It's also important at this time to re-install the tensioner using a 4 inch bolt as to just barely take up the slack, yet not pull on the chain. This will prevent the chain from slipping. Once that is done be sure to get everything ready, such as the master link, the chain and a magnet. Remove a link by grinding the two pins flat. BE CAREFUL! You can get any shavings in the engine! You also can not drop any of the clips, links or anything else in the engine! Be sure to cover the area with rags when working with the links and clips but be sure to remove the rags when you are turning the engine.

In the photo above you can see me joining the new chain to the old chain using one of the new master links. BE VERY CAREFUL NOT TO DROP THE CLIPS IN THE ENGINE! KEEP A MAGNET HANDY! MOST IMPORTANT - NEVER RE-USE A MASTER LINK C-CLIP! THEY ARE ONLY GOOD FOR ONE USE! THIS IS WHY I SUGGEST GETTING TWO MASTER LINK KITS! One for rolling the chain in and one for final assembly.

In this photo I have the new chain linked to the old chain. I have the new chain lying across the engine. You only have to hook the chain up to ONE side. Your extra set of hands (helper) will be turning the engine clockwise (right) 1/4 turns at a time which will draw the new chain onto the sprocket. At the same time you must keep the other side taught as the old chain feeds out, you must also hold down on the sprocket as the new chain is feeding in to prevent it from slipping. It is a very complex action that must be done right without any screw ups! Your helpers arms will be tired, and your hands and arms will hurt afterwards. No margin for error here, however if this scares you they do sell a tool that makes errors less of an issue. I suggest going that route if you are a DYI guy as you may not be familiar enough with feeding the chain and end up costing yourself 5 times what the tool cost.

Here we have the new chain fed into the engine and the master link installed.

Here you can see the right passengers side cams are in the proper position.

Here you can see the left drivers side cam is also in the TDC position. You should also have your balancer at "0" (Zero). If that is the case you now install your distributor ensuring the hash marks line up at the #1 position.

Here you can see the SECOND master link kit installed with fresh c-clips. You are now done with the timing chain and guides. Install your new tensioner and gasket now, tighten your camshaft sprockets; then roll the engine over by hand 4 times. After doing so you should still be able to bring the engine to TDC with all the cam marks dead on with the balancer at zero. If this is the case congratulations! Put the engine back together and enjoy another 60-80K in worry free miles!

But wait! This one had a broken guide with chunks missing!

Dont forget to clean out the pan if your guides are missing chunks! As you can see in the photo above, it's not pretty! Clean it up and all should be fine.



-- Edited by SELLC on Thursday 17th of January 2013 03:40:19 AM

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Yo SELLC,

Congratulations on an awesome thread ! It very-well points out why you need to take your car to someone who knows what they're doing for a job well done.

Cheers,

Rastus

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SELLC,

 

Great job with the documentation.  It was very helpful.  One problem that I am having and could use your advice.  I have a 1986 420 SEL that I have recently replaced the top timing chain guides and the timing chain.  Everything is at TDC and perfectly aligned. The distributor is pointing at #1, Crank at zero degrees, driver cam aligning perfectly but my passenger side cam is slightly off.  When I rolled in the new timing chain it worked great.  Not one link off. But if you look at the attached picture you will see that it is not aligning perfectly.  If I roll the chain back onePass Cam Pulley.JPG link it is even off more in the opposite direction.  Did I mess something up or do I have to replace my cam pulley due to excessive wear.  The car only has 120,000 miles.

 

Thanks to the help!!!



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I had the same problem once... Turned out to be the chain!

Rolled in a new MB chain and it was dead on. It was crazy and I never got my money back from the supplier for the faulty chain.

Mercedes does sell offset keyways to adjust this, and that is the direction I was going at first when I had this problem, but I decided to roll in a new chain and sure enough, problem solved.

Yes the chain sprockets can wear and cause something like this to happen, however that would have to be one heck of a worn sprocket. What was the brand of the chain you used? IWIS is also a good chain if you dont want to buy Mercedes brand, and to be honest when you open up the box an IWIS chain is what comes out.

It looks like a classic case of chain streach, and I have seen this before with brand new chains. You can use an offset key, but I would try rolling in another new chain.



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I did not check the brand of the timing chain, but I did purchase both the guides and the timing chain from the local Mercedes dealership.  I assume that they were genuine MB parts.  I will verify tonight when I get home.

 

 



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Looks to me like you got a bad chain. Like I said, I had the same problem with a 560 SL that I was working with and a new chain brought it right back to normal. It was a brand new chain also! Anymore I get the IWIS, just because thats what comes out of the Mercedes box anyway. That and the fact my local parts supplier delivers them to me, and I don't have to deal with the sometimes not so bright people behind the counter at Mercedes dealerships.

Like I said, Mercedes makes offset keys, but if it were me I'd want a proper chain. I seriously doubt your sprockets are messed up @ 120K miles, although the photo you posted really does not show the sprockets too good. Either way, I'm thinking you got a defective chain because I too had this problem and it was resolved by getting a good chain.



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Id imagine this is what my engine will look like when I do the guides tonight... Maybe a little cleaner inside... Anyone want to lay odds?



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hi, all. thanks for the excellent original post. used it to replace my 1972 280SE 4.5's timing chain this weekend (first timer here).

BUT I HAVE AN ISSUE: it won't start.

i screwed up and got the camshafts out of alignment, but worked them back out so all marks align (crank is at 3° ATDC, both cams are dead-on their marks) after 3 complete rotations of the crankshaft by hand with no resistance. at TDC the rotor is pointing to the #1 cylinder (pointing 180° from the mark on the distributor body). i did not remove the distributor to do the project. the plug wires are all put on their correct plugs.

so i have everything buttoned back up and she won't start. i get plenty of power to the starter, and it's turning the engine over easily. have not heard any resistance. i smell fuel, the plugs were hot after i pulled one. what could be the issue? anyone have any idea?

i read the crank rotates 2x for every 1x the camshafts rotate. is it possible that i have the crankshaft off phase even though everything lines up as described?

i'm stuck. any help us appreciated!



-- Edited by tbgrt on Sunday 3rd of March 2019 06:50:01 PM

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Tim


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Good luck TB, there are people here can and will help you.

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Shawnee_B wrote:

Good luck TB, there are people here can and will help you.


 thanks, shawnee. i'm hoping so!



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tbgrt wrote:

hi, all. thanks for the excellent original post. used it to replace my 1972 280SE 4.5's timing chain this weekend (first timer here).

BUT I HAVE AN ISSUE: it won't start.

i screwed up and got the camshafts out of alignment, but worked them back out so all marks align (crank is at 3° ATDC, both cams are dead-on their marks) after 3 complete rotations of the crankshaft by hand with no resistance. at TDC the rotor is pointing to the #1 cylinder (pointing 180° from the mark on the distributor body). i did not remove the distributor to do the project. the plug wires are all put on their correct plugs.

so i have everything buttoned back up and she won't start. i get plenty of power to the starter, and it's turning the engine over easily. have not heard any resistance. i smell fuel, the plugs were hot after i pulled one. what could be the issue? anyone have any idea?

i read the crank rotates 2x for every 1x the camshafts rotate. is it possible that i have the crankshaft off phase even though everything lines up as described?

i'm stuck. any help us appreciated!



-- Edited by tbgrt on Sunday 3rd of March 2019 06:50:01 PM


 Yo,

Your distributor & camshafts rotate together at 1/2-speed of the crank-shaft. Since your camshafts are aligned at TDC with the crank, your distributor must be 180-degrees out.

Set your cams & crank up to TDC, & then lift out your distributor enough to rotate the rotor-arm 180-degrees. There's a mark on the distributor housing ( notch ) to align to. The rotor moves when meshing with the gear, so you may have to lift & adjust a few times to get-it-right.



-- Edited by Rastus on Sunday 3rd of March 2019 07:38:00 PM

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tbgrt wrote:
Shawnee_B wrote:

Good luck TB, there are people here can and will help you.


 thanks, shawnee. i'm hoping so!


 See that? Rastus already on it! 



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THANKS RASTUS! i'll adjust as noted and report back. really appreciate your help.



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Tim


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Rastus wrote:

 Yo,

Your distributor & camshafts rotate together at 1/2-speed of the crank-shaft. Since your camshafts are aligned at TDC with the crank, your distributor must be 180-degrees out.

Set your cams & crank up to TDC, & then lift out your distributor enough to rotate the rotor-arm 180-degrees. There's a mark on the distributor housing ( notch ) to align to. The rotor moves when meshing with the gear, so you may have to lift & adjust a few times to get-it-right.



-- Edited by Rastus on Sunday 3rd of March 2019 07:38:00 PM


 PERFECTION! rotated the distro 180° and timed it to the book and she's running like a champ. really appreciate the help here, Rastus (and the moral support Shawnee_B). i was completely stuck.



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Good deal!

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benz_va wrote:

SELLC,

 

Great job with the documentation.  It was very helpful.  One problem that I am having and could use your advice.  I have a 1986 420 SEL that I have recently replaced the top timing chain guides and the timing chain.  Everything is at TDC and perfectly aligned. The distributor is pointing at #1, Crank at zero degrees, driver cam aligning perfectly but my passenger side cam is slightly off.  When I rolled in the new timing chain it worked great.  Not one link off. But if you look at the attached picture you will see that it is not aligning perfectly.  If I roll the chain back onePass Cam Pulley.JPG link it is even off more in the opposite direction.  Did I mess something up or do I have to replace my cam pulley due to excessive wear.  The car only has 120,000 miles.

 

Thanks to the help!!!


 

I should also mention I have seen situation before where the right passengers side camshaft will appear a little off due to the inherent kickback of the camshaft on that side.

As I am sure you already know the passengers side cam must be rotated and held to stay in the proper possition when installing the chain because the lobe position and valve spring pressure does not allow for a resting stop in the proper alignment possition.

The cam will want to kick forwards or backwards if not held when installing the chain, it can also jump a tooth due to the slack of the chain until the tensioner is installed taking up the slack.

I did have a bad chain once, although indexed keys are made for micro adjustments.

Since we haven't heard back from you I'm guessing you just left as-is and all has been fine and the slight misalignment was just the cam kickback making it just appear a little bit off. I think you will find if you put a 22mm on the cam nut you can take up the small amount of slack and it will be near dead on, without seeing any movements on your crank or left side timing marks.

 

Edit - Although it should be noted that indexed keys are generally used when an engine has had machine milling work done to the heads or block and performance camshafts and such.

I think in most cases a worn or slightly out of spec chain causes this small variance, and I have seen it often. It could also have something to do with worn cam, idler or crank sprockets, in addition to wear marks on the lower guides if they have not been replaced. All of these can add up over time but what has been shown is not even close to being one tooth off. Being just one tooth off will cause issues, so it's understandable that some people will want it dead on but that could get pricey. I doubt most would even notice in actual driving conditions anyway, but if you got deep pockets, you got deep pockets.



-- Edited by SELLC on Saturday 15th of May 2021 08:37:46 AM



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