Chain Replacement Tool
 

I'm starting to gear up to replace the timing chain on my 617. I decided to build a guide tool to facilitate threading in the new chain and removing the old one.

Here is the thought process and the fabrication steps in building the tool.

I first fabbed up a base plate for the tool, tieing in to the bolt for the front lift point as well as an unused bolt hole lower and to the left. In addition I have a bolt in the pin for the upper chain guide to provide a third reference point.

http://www.peachparts.com/shopforum/...1&d=1401153898

Next, I fabricated the front support piece. The center hole rides against the cam gear for support and centering. I also clearanced for the chain guide bolt to get the right alignment.

http://www.peachparts.com/shopforum/...1&d=1401153908

I next cut and carefully bent the chain guide to fit closely against the chain.

http://www.peachparts.com/shopforum/...1&d=1401153920

Then just welded things up and cut the hole for the chain access. Even though the rig is quite sturdy, I added a rear support member that ties into the valve cover bolt on the drivers side.

http://www.peachparts.com/shopforum/...1&d=1401153937

Here's another view.

http://www.peachparts.com/shopforum/...1&d=1401153947

The final step will be to powercoat the tool.

This should make the job pretty quick and easy and I should be able to do it by myself.

Nice! What's the theory of operation? Keeps chain pressed against cam sprocket at all times?

Very important to keep the chain against the cam gear. The jig really looks awesome, but to be quite honest; my daughter and I rolled one in 3 weeks ago on my 85 300d using zip ties. Real simple, add a zip tie, turn crank add zip tie, remove zip tie. Chain was rolled in and ready for crimp in about 15 minutes.

Do you have a crimp tool?

Also very important to clean area where chain tensioner and thermostat housing will mount. I used a die grinder with a scotch brite wheel. When ordering gaskets, order 2 just in case there is a leak; better to have on hand than to have to wait a week for parts (ask how I know).

very kewl
 

Okay, I'm impressed! Looks like it'll beat my ol' tried 'n true "zip tie" method! So what are your thoughts here, make these, go into production, offer 'em up for sale, maybe per order basis? Or just tease all the rest of us, whetin' our appetites? Rent the 'one off'? Inquiring minds wanna know!

Precisely. If you read some of the how-to threads, people are using two people and tie wraps, vice grips and all other manner of devices to keep the chain intact and snug on the cam gear. This tool makes it virtually impossible to screw up the job by having the chain jump a tooth.

Here's the one whunter made. I wanted to try a different design.

http://www.peachparts.com/shopforum/...ga33460005.jpg

The main thing is just to share my thoughts and design so anyone with the desire and tools can make their own...also to get feedback and discussion toward making tool fabrication easier and better. It's untested as of yet, so assuming it works well, I might make it available in the tool sharing site.

I learn so much from others that share their knowledge on the forum, just want to share what I'm learning/doing relative to keeping these old diesels on the road.

Very nice!

My mechanic used this tool when he replaced the chain in my 300D
https://farm9.staticflickr.com/8195/...c99d63e6_z.jpg
https://farm9.staticflickr.com/8325/...5122b77a_z.jpg

There is a provision to mount to one of the head bolt holes, but he opted not to remove it for obvious reasons. He simply used a vice (also visible in the images) to fasten this rear section.

https://farm9.staticflickr.com/8190/...316797ef_z.jpg

Nice, I wish I had gone with their design of the "link window"... it would have added a bit of strength on that side.

Are you sure your chain guides are still good?

In preference to something like this I'd just remove the rocker arms cut the chain and fiddle about to my heart's content!

It is nice to build tools but only if you have storage space for them or use them a lot

Patent Pending?

It also covers the problem of stuff dropping down the Timing Chain Tunnel and reduces the chance of particles from grinding or cutting off the Timing Chain from getting into the Engine.

I have not read the proceedure closely but can the Large Timing Chain Rail can be removed and replaced before you change the Timing Chain?
If it can be removed like that after you install the large Timign chain Tensioner Rail just don't put the Tensioner on till the New Chain is installed.

Question for anyone about if it is really needed to replace the 2 lower Timing Chain Rails; see diagram?

I think your "window" for accessing the chain is too small.

I actually purchased the official MB tool for replacing the timing chains on OM60X engines. It bolts to the head using two of the 10mm bolts from the valve cover. It has a very wide "window" which really only holds the chain to the sprocket at two places about 180 degrees apart. Works just fine.

I estimated the window based on other tools. It appears that 5 link pins might be the sweet spot, based on the configuration of the "official" tool.

http://www.peachparts.com/shopforum/...1&d=1401217793

If it needs to be a bit wider, a quick swipe with a cutting wheel on an angle grinder will do the job...except it will screw up the powdercoat. I'll know soon enough.

Here are the pieces coming out of my powercoating oven.

http://www.peachparts.com/shopforum/...1&d=1401219844

And here's the finished product.

http://www.peachparts.com/shopforum/...1&d=1401219967

Before going to powercoat, I decided to add a stiffener to the vertical to provide some additional strength to the chain guide.

http://www.peachparts.com/shopforum/...1&d=1401220086

I don't know how much pressure is being applied in the pulling direction on the chain, so this is just cheap insurance to make sure I've got enough stiffness to prevent the chain from jumping a tooth.

If I remember correctly you'd have to remove the tensioner and the camshaft cog to get the largest rail out. The bottom ones on the right of your picture require removal of the timing device (and vacuum pump of course) and I think it is prudent to remove the sump too to catch / find anything you might drop whilst doing the job!

Has someone got his own powder coating set up?

http://www.peachparts.com/shopforum/...haintool-8.jpg


Nice!

Yes...it's actually easier than you might think.

You need a gun ($50 or so), a compressor capable of 15psi, an oven ($10 at a garage sale) and powder ($5 a pound and up depending on color and quality). In addition to my small parts toaster oven I've got a two bay kitchen oven I got for free that I've done larger parts like wheels and even a VW engine block in.

I have been encouraged (by someone here) to do this as well. I got the impression the oven was very important though - that the temperature had to be really really industrially bang on. Perhaps not?

Have you got an electrically charged solution to the process too?

The temps are not critical at all. The particular powder I used on the chain tool has a cure time of 20 minutes at 375. If it was critical you would expect to see something like 373 for 21 minutes. There's no pre heating needed, just pop it into a cold oven bring it up to temp and then time the cure interval as specified. For very large pieces you can even use UV heat lamps to set the powder - no way you can get the temperature spot on with those.

The powder guns come with an electrostatic connection. The powder is given a charge coming out of the gun, and the piece is given the opposite charge, so it not only is attracted, it sticks.

Cool - right I'm officially shopping for an oven (my domestic charms will finally come in handy)

I think Paul and I will be working together to offer these tools (his guide tool, my crimper) on the rental/borrow program.

I'll lend my chain crimper tool and my pin puller in exchange for borrowing the tested and approved chain guide. I have two 300SD timing chains to do this summer.

The testing phase will begin shortly. I'll post pictures in this thread. As of this point in time, it's merely a design concept with a prototype.

Well I can report that the Mach4 Chain Tool ver 1 works like a charm. I tackled the job today with some level of trepidation, but like everything the job went way smoother than anticipated. Not knowing how much tension is on the chain during the process, I clearly over-engineered the tool, but better that than slipping a link!

I first mounted the tool on the engine.

http://www.peachparts.com/shopforum/...1&d=1405651177

I then isolated the grinding area as much as possible to prevent grinding dust from getting into the engine and to prevent anything from dropping down into the engine.

http://www.peachparts.com/shopforum/...1&d=1405651386

I used a Dremel with a cutoff wheel to remove the crimp from the chain.


http://www.peachparts.com/shopforum/...1&d=1405651386

I used a clip on master link I salvaged from my original SL engine to join the two chains and began dragging the new chain in using the old chain.

http://www.peachparts.com/shopforum/...1&d=1405651386

When the new chain was in, I set up the new link for crimping. I'm "borrowing" Rollguy's crimper and it should be in tomorrow so I can finish the job.

http://www.peachparts.com/shopforum/...1&d=1405651386

While I had everything apart I pop tested my injectors, inspected and tested the glow plugs and of course replaced the tensioner spring. I'll also do a valve adjust and re-polish the valve cover before buttoning things up.

As usual, awesome job!:2thumbsup

The crimp tool really does a quality job. The crimp made by the tool is virtually indistinguishable from those on the rest of the chain.

http://www.peachparts.com/shopforum/...1&d=1405794729

I was initially thoroughly confused about how the crimper works in that there are two positions for the crimping die. The first is to press the link onto the chain. And the other is to actually make the crimp. It's completely obvious once you understand the design, but it took me a bit to figure it out. Hopefully this will help someone else avoid the confusion for their job.

http://www.peachparts.com/shopforum/...1&d=1405795616

My polished valve cover had gotten kind of drab and oxidized, so I took the opportunity to throw a little aluminum polish on it to bring it back to life.

http://www.peachparts.com/shopforum/...1&d=1405795647

Since the chain tool works so well, I'll make it available in the tool rental on this site. It truly makes a two person job easy and safe for one person.

that valve cover is Mercedes classic center quality.:thumbsup:

I think you have the arrows mixed up?

No the face with the two dimples, magnet and shaped like a link is the face you use to press the outside link onto the master link in preparation for crimping. The magnet holds the link while you position the tool.

The other face has the bevels for applying the crimp.

I've got the tool packed up for shipping back, but I might open it up to take a better picture.

That's interesting, as looks like the side with the magnet is the one that swedges the ends of the links, and the other side (facing the chain) is for pressing on the link face. I know that the last time I used it, I used pliers to tighten the link together, and crimped it with the face with the 2 dimples. It seemed to work fine, and the car is still on the road today. I am not sure if or what I might have done wrong by doing it this way. Either way, it is nice to know it worked great for you...Rich

Mach4 is correct. The crimping side is to crimp ONE stud at a time. The side with the dimple is to press the face plate in. I normally use a vise to press the face plate in, undo it then use the tool to press it in as it is very tight.

I think using the dimple side would still work if you tighten it enough. What needs to happen is to flatten the 2 studs and it is very unlikely for the master link to come off.

No that's absolutely wrong! You can't tighten the tool enough to put a noticeable crimp in the end. I know because I thought I was going to break the crimper trying to add enough pressure to deform it.

Because there is so little lateral stress on the link, the tight press fit coupled with some visually unnoticeable deformation is probably enough to keep it on - actually it is because you've demonstrated it. :)

I'd suggest you re-crimp the link next time you do a valve adjust...maybe sooner.

I don't know if it's my imagination, but the car idles with noticeably less "clatter" and runs noticeably smoother. I don't think it's in my head, as I attribute this to the change in timing due to a zero-stretch chain compared to the old stretched one.

Anyway it's done...probably for the life of the engine. And I drive a bit more relaxed now knowing that I don't have a ticking time bomb under the hood ready to strand me at a most I opportune time. OK I've still got the vacuum pump, but I'll live with that one for now.

Now you have me wondering. The car belongs to a family member of a friend of mine, and he drives it every day. When I get the crimper back, I will examine it (I am sure I will find exactly what you are describing). I guess my original post about your arrows was because it looked like the crimper side of the die was not long enough to crimp both parts. As Bob (ah-kay) pointed out, it is done one at a time. That now makes sense, and I think I should fix it on the car before something bad happens......Rich

Mach4, it sounds like instructions were not included with the crimper? I wonder if instructions were included with the crimper when Rollguy bought it?

No instructions were with it when I bought it new.....Rich

May not be a bad idea to get one from the manufacturer.:eek:

When I was struggling with figuring out how it works, I did a cursory search on line and found nothing useful. It's one of those things that once you understand how it works, it's intuitively obvious, but without the big picture it's as clear as mud.

In fact the following picture from the DieselGiant site with the how to change the timing chain comes after he has "crimped" the link, allegedly showing what it looks like after crimping (How to Replace Your Timing Chain)

http://dieselgiant.com/P1010101.JPG

Sorry, that link is not crimped!

It appears that I am not the only one to have not figured that out!

Which raises an interesting point. What's all the hoopla about not using a removable master link on a diesel chain? If the link apparently stays in place without any appreciable crimp, wouldn't it be infinitely more likely to stay in place with a link securely fastened in place, albeit removable.

Let me hasten to add I'm not advocating this, but it's an interesting question to be sure. And the chain on my 380SLs engine had a dual timing chain with a master link.

Kinda makes ya wonder...

Here are some pictures that show what is going on.

This picture shows what I'm calling the "pressing face", which is designed to press the link onto the rest of the chain. It's a very tight fit, in fact I actually relieved the link just a bit with a micro-rat tail file to make it easier to get on. The link fits into the recess and is held in place by a magnet (the silver insert at the top).

http://www.peachparts.com/shopforum/...1&d=1405910811

Here is the crimping die face. It's designed to do one chain half at a time. In fact, if you look closely you can see the slight mark left by the crimping process.

http://www.peachparts.com/shopforum/...1&d=1405910811

And here's an extra link in crimping position to illustrate how the crimp is applied to the link.

http://www.peachparts.com/shopforum/...1&d=1405910615

And finally, here is an image that shows the two sides of the die in the press. It just sits on a pin and can be rotated 90 degrees to put the appropriate face into position for use.

http://www.peachparts.com/shopforum/...1&d=1405911262

Hopefully this will be helpful for others along the way to avoid the confusion and angst I experienced trying to get my chain properly crimped.

This is one of the best threads I have read in a long time. Thanks everyone.

And very enlightening to me as well!

The PeachParts forum was so helpful to me as I was doing my engine swap and learning about 'Benzes for the first time. It's nice to contribute back and be a part in growing the knowledge base and developing relationships.

agreed.

thanx so much

It appears that there is another beneficial side effect to the new timing chain and that is an increase in fuel mileage. On the most recent tank, with a driving profile that would normally produce right at 30 mpg I got 32.7

Now one tank does not confirm this, but it is definitely a significant indicator.

It also appears that there is less smoke (soot) now too.

I'm happy.

I have this project coming up shortly. Perfectly explained. Thank you.

So, DieselGiant did not use the crimper correctly and posted a photo showing a "crimped link" when in fact it was not crimped? I wonder how many engines were ruined as a result?

Someone should contact him so that he can correct the tutorial.

I know I have done at least 2 this way, and they are still on the road. It takes a good amount of pressure to press the link on the end, so I am not too worried. However, I am going to do my best to correctly crimp the links in both cars before something bad happens....Rich

Here's the entire crimping sequence on his site.

http://www.peachparts.com/shopforum/...1&d=1406388850

And digitally enhancing the first image clearly shows the crimping face of the die not being used.

http://www.peachparts.com/shopforum/...1&d=1406388864

He might say that this image is pressing on the link in preparation for crimping, but there should definitely be an additional two images showing the crimper being used with the crimping face and the final product with the mushroomed pins. To his credit, he says it but does not show it... which is very misleading.