ok, got the tensioner rail pulled.

first, make another puller.

again, for this puller I tried to stick to only parts available at lowe's / home depot. however, because of its construction style, it will essentially be a single-use puller (it'll fall apart after you are done with it).

to create the "bridge" part of the puller, you'll need:
* eight 1/4" nuts (I mistakenly have six in the picture)
* some quick-set epoxy, super glue, or possibly even hot glue
* a big-ass washer of your choice

http://i.imgur.com/svhCf.jpg




for the extractor part of the puller, you'll need:
* one 8mm x 50mm bolt (1.25mm pitch)
* one 8mm nut
* an appropriate washer stack to seat the 8mm nut onto your big-ass washer.



using a nickel as a guide to space the nuts apart, glue two stacks of 4 nuts onto your big-ass washer.

http://i.imgur.com/KSdUf.jpg



use a penny to apply some pressure as your adhesive sets, to ensure the nuts are square to each other (they are going to be under a lot of pressure when in use -- make sure they are seated square!)

http://i.imgur.com/QRb3Hl.jpg



using the puller:

first, rotate the crank so that one of the gaps in the crank balance wheel is lined up with the lower tensioner rail pin.

remove the tensioner. to do so, first remove the spring cap. note: its under pressure from the spring -- don't let it fly across your workshop when you loosen it.

http://i.imgur.com/cm0Qy.jpg



pull out the spring.

http://i.imgur.com/LJtu3.jpg



remove the tensioner body.

http://i.imgur.com/hQaUN.jpg



clean up the area around the pin, and clean up the threads of the pin with a tap (8mm x 1.25mm pitch). also, remove the bolt denoted in the picture.

http://i.imgur.com/BIv9q.jpg

http://i.imgur.com/BgO0Q.jpg



situate the puller like so. extract the pin by tightening the nut. you shouldn't need to secure the bolt with a wrench -- it should stay in place. you can see that I didn't quite wait long enough for the epoxy to fully cure, as the nuts are moving around a bit under pressure.

http://i.imgur.com/dzomY.jpg

http://i.imgur.com/Sf3zz.jpg



at this point the pin should be loose enough that you can pull it out by hand.

http://i.imgur.com/yaATE.jpg



most likely, the nut-stacks will work themselves free from the expoxy, and will fall away from your big-ass washer when the pin frees itself and releases the tension.

http://i.imgur.com/XPxkn.jpg



finally, remove the cam sprocket so that you can pull out the tensioner rail (which is now loose). I zip-tied the chain to the sprocket so that I would be sure not to disturb the timing.

there is a washer and lock washer on the front of the sprocket, as well as a washer on the back of the sprocket.

http://i.imgur.com/kgepG.jpg



you don't want these falling into the oil pan, so put plenty of rags in place to catch them in case you don't grab them in time.

http://i.imgur.com/qu6FV.jpg



I've read on this forum that some people have trouble with the cam itself sliding backwards once the sprocket is removed. i used a zip tie around a cam lobe to secure it.

http://i.imgur.com/LA8LO.jpg



pull the sprocket. you should be able to horse it off of there by hand. here, you can see how I nearly lost the back washer down into the engine. this is why you use the rags!

http://i.imgur.com/Z4ZHP.jpg



move the sprocket over to the side, keeping tension on the chain. zip-tie it into place.

http://i.imgur.com/epplQ.jpg



at this point you should be able to reach in and pull the tensioner rail out of the engine.

the rubber-like surface of mine appears to be pretty well worn, but it doesn't look like it wore all the way through to the metal backing.

http://i.imgur.com/w0olU.jpg

http://i.imgur.com/VNDjs.jpg

http://i.imgur.com/58792.jpg

if you are going further, the next step is to pull the injection timer (you need to pull this in order to remove the lower guides).

first, temporarily place the sprocket back on the cam, so that you can rotate the crank.

http://i.imgur.com/0N32I.jpg



rotate the crank until one of the crank balancer cut-outs is lined up with the "hidden" pin of the lower guide. (you will need to pull this pin later, but you need to go ahead and line up the crank now, because you can can't rotate the crank after removing the injection timer).

http://i.imgur.com/6HKvs.jpg



now, remove the cam sprocket again. this time, hang it over to the left, using zip ties to secure it to the alternator belt tension adjustment bolt. this way, it will be very convenient later to tighten up those zip ties with one hand (to keep tension on the chain as you remove the injection timer).

http://i.imgur.com/ngxH8.jpg



you need to pull the upper pin of the lower guide, so that it can pivot to give the chain enough clearance so that the injection timer will clear the chain.

same old procedure. clean up the threads with a tap (6mm x 1.0mm pitch).

http://i.imgur.com/Y48bi.jpg



using the puller you created for the upper "triangle"-shaped chain guide, pull the pin.

http://i.imgur.com/S5648.jpg

http://i.imgur.com/kD6TP.jpg



mark the position of the chain relative to the injection timer. this is extremely important. I used a solid paint marker, which are available at any welding supply shop. (you may notice these marks change in later photos -- I had a bit of trial-and-error before getting the sequence of these steps correct).

also, remove the center bolt securing the injection timer.

http://i.imgur.com/LkqYU.jpg



fashion a chain shim out of sheet metal, using tin snips. you may be able to get away with using strong plastic sheet (milk jug?).

http://i.imgur.com/GsHmR.jpg



insert the chain shim on the left side of the injection timer.

http://i.imgur.com/qno8n.jpg



rotate the shim around the injection timer so that it lifts the chain off of the sprocket teeth.

http://i.imgur.com/tvIUc.jpg



remove the injection timer. I couldn't get a good grip on it, so I used the arms of a two-jaw puller (from harbor-freight) to give it a tug. (note that I did NOT use the puller in its normal mode of operation -- I just stuck the arms in and gave it a tug by hand).

http://i.imgur.com/QXsO9.jpg



as you pull the injection timer out with one hand, keep the other hand on the cam sprocket, so that you can rock it over and take up the chain slack as soon as the injection timer and shim clear the chain. keep tension on that chain! put down the injection timer and use that hand to cinch up the zip ties to keep tension on the chain. you should see something like this:

http://i.imgur.com/g4sgp.jpg



note that there is a woodruff key on the intermediate shaft. remove this woodruff key using a magnetic picker-upper so you don't drop it. DO NOT DROP THIS KEY INTO THE OIL PAN.

with the injection timer out of the way, reinforce your paint marking on the timing chain if you can still reach that link. I had a hard time getting the solid paint marker far enough into the engine to get a good thick mark on the chain while the injection timer was still in the way.

http://i.imgur.com/Elvl4.jpg



stay tuned for removing the lower guides...

ok, time to ask for help again.

I've replaced the lower chain guides, and I'm trying to drive the pins back into the block. I'm asking for advice on the recommended way to do this.

I was able to get them most of the way in by threading in a 6mm x 20mm bolt and beating the heck out of it with a rubber dead-blow hammer, but I can't drive it in that last 1/4" or so.

I thought I'd ask for advice before I do something stupid.

http://i.imgur.com/JVp0M.jpg

Great thread, buddy.

You will need a regular hammer. Don't be shy. Hit the bolt square-on, start easy if you are uncertain. You'll feel better once it moves a bit. Put sealant on the heads before you drive them home.

After they are in, you need to center the rail on the pins (along their length)

That is more classically the symptom for worn valve stem seals..... much cheaper and easier to do....

Thanks! Thats what I was hoping to hear.

on to removing the lower guide rails.

there are two lower guide rails: the top lower guide rail and the bottom lower guide rail.



the bottom lower guide rail:

first, we'll remove the bottom lower guide rail. you've already removed one of its pins while removing the injection timing device, so you just need to remove the second pin and pull the guide out through the hole where the injection timing device sat.

same procedure. clean up the threads of the pin (6mm).

http://i.imgur.com/N7S6e.jpg



using your trusty 6mm puller, pull the pin.

http://i.imgur.com/6rvlq.jpg

http://i.imgur.com/H4L4p.jpg



remove the guide rail.

http://i.imgur.com/wq2Aq.jpg



the top lower guide rail:

next, removing the top lower guide rail. similarly, it is held in by two pins. the top pin is a bolt-in pin. remove it using a 24mm socket.

http://i.imgur.com/J15oF.jpg



cleaning up the threads of the lower pin for the top lower guide rail was difficult, because my tap handle wouldn't fit in the recess of the timing wheel. I had to use a crescent wrench.

http://i.imgur.com/ZatPU.jpg



pulling this bolt requires a bit more ingenuity. the longest bolt you can get with threads along its entire length is 50mm, which is too short to get past the outer surface of the timing wheel.

I got lucky and found some 6mm all-thread at my local ACE hardware store.

make a puller by cutting off 6 inches of all-thread. use an appropriate washer stack against the face of the timing wheel.

http://i.imgur.com/m7SmC.jpg

http://i.imgur.com/TYq3t.jpg



the timing wheel will make a loud, ringing "BING!" when the pin breaks free.

http://i.imgur.com/Eit3i.jpg

http://i.imgur.com/KYldH.jpg



pull out the top lower guide rail.

http://i.imgur.com/zyhaa.jpg



pin wear:

it was interesting to note that the plastic guide rails had created polished spots on the pins where they rubbed.

http://i.imgur.com/6nZTI.jpg

http://i.imgur.com/73ToS.jpg

next, installing the new lower guide rails.

this is the arrangement of the two lower guide rails:

http://i.imgur.com/AoqHc.jpg



install the new bottom lower guide rail:

insert the two pins far just far enough that they protrude into the timing chain cavity, and insert the new guide rail.

http://i.imgur.com/5Mvle.jpg



using a rubber mallet, drive in the pins while positioning the guide rail until you feel them align.

EDIT: don't insert the upper pin until after you've re-installed the injection timing device, as you have to be able to move the bottom lower guide rail out of the way so that the sprocket teeth on the injection timing device will clear the chain. I made the mistake of installing both pins of the bottom lower guide rail before reinstalling the injection timing device, and as a result I had to pull the upper pin a second time... the order of these pictures reflects that mistake.

http://i.imgur.com/Q3V1a.jpg



before driving the pins home, apply some sealant. I used blue RTV.

http://i.imgur.com/Y67g0.jpg



driving the pins all the way in requires quite a bit of force. I inserted a 6mm bolt and used a mini-sledge to drive them home. you will hear the sound of the mini-sledge change when the pin bottoms out.

http://i.imgur.com/beCvW.jpg

http://i.imgur.com/5HmKi.jpg



clean up the excess RTV.

http://i.imgur.com/6Wu1K.jpg

http://i.imgur.com/8FKY7.jpg

I meant to post this earlier, but here is the detail of how the guide rails interact with the pins. the guide rails have a "sprung loaded" lip (the tip of the pin is just starting to make contact with it in this photo) which seats into the groove in the pin as you insert the pin. this is what keeps the guide rails from moving along the pin.

http://i.imgur.com/KSC08.jpg



install the new top lower guide rail:

insert the new top lower guide rail through the hole left by the injection timing device. Insert the lower pin on the end of a 6mm, 50mm long bolt and line the guide up with the pin. remember to put some sealant on the rim of the pin.

http://i.imgur.com/aM4wZ.jpg



you will need to use a punch to drive the pin all the way home, as the bolt goes just past the face of the timing wheel, so you can't directly hit the bolt with a hammer for the last few hits.

http://i.imgur.com/ILlJH.jpg



on to the bolt-in pin.

I didn't realized there was a copper crush / sealing washer behind the bolt-in pin in time to order a new one, so instead I just annealed the one I had.

copper work-hardens, and is annealed by heating until red, then quenching (this is opposite from steel, which hardens when quenched).

I used this to great effect when using harbor-freight copper crush washers while rebuilding the brake system on my truck. see annealing copper crush washers fixed my brake leak - The 1947 - Present Chevrolet & GMC Truck Message Board Network

I used a MAPP-gas torch to heat the washer on a "fire brick" (available at a ceramics / pottery / kiln supply).

http://i.imgur.com/rOcle.jpg



I didn't have a big enough tap to clean the threads, so I used simple green and q-tips.

http://i.imgur.com/b7kBA.jpg



tighten the bolt-in pin to drive it home. I used blue thread-locker on it.

on to reinstalling the injection timing device.

I have to say, this was by far the hardest part of this project. it introduced the highest risk of dropping a component into the oil pan, and was the part of this procedure most likely to result in accidentally slacking the chain enough to come lose from the crank sprocket.

if you are a psychic and can somehow determine that your lower guide rails don't need to be replaced, I would advise the more casual enthusiast to avoid removing his injection timing device all-together.

what's that? you're a hard-core glutton for punishment? me too! read-on then, fair reader.

this section is a bit sparse in terms of pictures because it involved critical processes involving both hands which couldn't be interrupted to take a picture.

the injection timing device:

this is the injection timing device (viewed from the backside) and the bushing which sits inside of it. note that they both have keyways.

http://i.imgur.com/xJSqK.jpg



these keyways line up, like so:

http://i.imgur.com/yHeGn.jpg



this is the slot where the woodruff key sits which lines up with those keyways.

http://i.imgur.com/H9ISv.jpg



how NOT to install the injection timing device:

place the woodruff key into its slot, and slide the bushing onto the shaft far enough so that about half of the woodruff key is exposed. with one hand, insert the chain shim to push the chain out of the way.

http://i.imgur.com/DA0oD.jpg



with the other hand, place the injection timing device onto its bushing. somehow miraculously slide the injection timing device into place while keeping the chain shim in place, while keeping the keyways of the bushing and timing device aligned, and avoid knocking the woodruff key out of place. also, avoid causing the woodruff key to rock backwards in its slot, such that its front edge prevents the timing device from sliding all the way onto its shaft.

while attempting to perform this miracle, make sure you drop the woodruff key at least three times, while having it somehow miraculously bounce outside of the engine instead of falling into the oil pan, and also make sure you slip with the chain shim several times, allowing the chain to go completely slack yet somehow miraculously not screw up its position on the crank sprocket.

swear profusely, the entire time, while simultaneously standing in awe at how you just miraculously avoided total catastrophe about six times in the span of an hour.

go have a beer and contemplate the lucky accident which was your birth, which allowed you to experience these setbacks in the first place.



how to install the injection timing device:

first, cheat.

apply a tiny dab of super glue to the woodruff key and place it onto its shaft. place some rags beneath it while doing this in case you drop it.

http://i.imgur.com/fnwaQ.jpg



next, be smart.

slide the bushing onto its shaft only just far enough to get it started and over the woodruff key (maybe half an inch onto the shaft), so that it looks like a tommy gun. place your chain shim.

http://i.imgur.com/DKOY8.jpg



now, with one hand, you will be able to grab the injection timing device and start to slide it onto the bushing. the key is that with the bushing out this far, you will be able to reach behind the timing device with a few fingers to prevent the bushing from simply being pushed further down the shaft by the timing device. once you have the timing device slid onto the bushing, look down its bore and ensure its keyway is lined up with the bushing's keyway.

once everything is aligned, you should be able to simply slide the injection timing device all the way back, and pull your chain shim out, which will seat the chain on the injection timing device's sprocket.

check your mark on the injection timing device against your mark on the chain. it will likely be a tooth off, as the chain will move slightly as the shim is pulled.

re-insert the chain shim and try again. with the chain shim in place, use the two-jaw puller (previously pictured) to rotate the injection timing device in very small increments. it will likely take you several tries to get the chain to land on the right tooth.

http://i.imgur.com/luDvZ.jpg



insert the bolt and washers / bushings to secure the injection timing device to the intermediate shaft. I wasn't really sure how to tighten this bolt without putting lots of tension on the chain, so I used an impact gun. probably not the ideal solution, as breaking this bolt or stripping the threads in the intermediate shaft would be catastrophic.

also, reinstall the bolt which prevents the chain from jumping off the injection timing sprocket.

http://i.imgur.com/w6mdt.jpg



NOW, you can insert the last pin of the bottom lower guide.

http://i.imgur.com/0K7Sx.jpg

install the new tensioning rail:

http://i.imgur.com/dLwEl.jpg



drop the rail into the top of the engine.

http://i.imgur.com/8cTNJ.jpg



you should see it line up with the pin hole.

http://i.imgur.com/VYrMx.jpg



I forgot to mention that I've been cleaning these pins (and all other parts) in an ultrasonic cleaner with simple green. oil the pin after cleaning the simple green off of it.

http://i.imgur.com/T10bs.jpg



apply some sealant to the pin and drive it home using a 6mm by 50mm bolt and a mini-sledge.

http://i.imgur.com/aZ89q.jpg



reinstall the bolt which you had to previously removed in order to position the puller.

http://i.imgur.com/D5BhG.jpg

replace the timing chain.

first, put the cam sprocket back on the cam, and bolt it back in place. I cleaned up the hardware in an ultrasonic cleaner.

http://i.imgur.com/wXx1D.jpg



next, we need to grind off the heads of chain link so we can break the chain. first, wrap up your sprocket (and exposed head) like megatron in the desert. we don't want metal shavings getting into the engine or dropping chain link bits into the oil pan.

http://i.imgur.com/UfTYs.jpg

http://i.imgur.com/IHksm.jpg



grind the link down. drive the pins out with a punch.

http://i.imgur.com/cBWce.jpg



pull the center piece of the link out with a magnet.

http://i.imgur.com/wdS4k.jpg



use this opportunity to examine the wear on your cam sprocket.

http://i.imgur.com/y0Eh9.jpg

http://i.imgur.com/Wex8Y.jpg



use a new link to attach the new chain to the old chain. ideally you'd use a master link with c-clips. I forgot to order one, but I had ordered two chain links, so I was able to get away with using up one of them to feed the new chain in.

http://i.imgur.com/9o78u.jpg



the plate of the new link will be a very tight fit on its pins. you will need to use your fancy chain tool to seat the plate on pins.

http://i.imgur.com/5U5AC.jpg

http://i.imgur.com/pCT99.jpg



I took a big risk and used this link like so (with the plate simply pressed on rather than riveting the heads of the pins) to turn the new chain in. this is not recommended procedure. just remember ahead of time to order a master link. DON'T GROW UP TO BE LIKE ME KIDS.

remove your rags from around the sprocket and rotate the crank to feed the new chain in. place the box containing the new chain on your alternator so it feeds in easy and doesn't get dirty.

http://i.imgur.com/0jRCo.jpg



as you begin to feed the new chain in, sever the zip-tie holding the old chain to the sprocket, but without keeping tension on the chain nor holding it in your hand. watch the chain fall into the engine. the cool thing is, the world switches into slow motion as you realize the magnitude of your own stupidity. this is cool, because the expletives streaming from your mouth sound funny in slow motion.

http://i.imgur.com/Jf7KN.jpg



use a pick to rotate one half of a link up so that you can hook it and pull the chain back out of the engine.

http://i.imgur.com/wzla7.jpg

http://i.imgur.com/KY3nC.jpg



now, keep tension on the chain like a good little gear head and turn the crank, feeding the new chain in. keep two zip ties on the sprocket at all times. you'll go through a lot of zip ties, and get quite good and threading and tightening them with one hand.

http://i.imgur.com/85nRX.jpg



eventually you'll see this:

http://i.imgur.com/VWWtJ.jpg



now, insert the link to connect the new chain to itself. ideally, you'd be able to get the pins through the middle plate, pictured here. unfortunately I was unable to do so, because it was too tight of a fit. I may end up taking my truck to a shop to have them replace this link.

http://i.imgur.com/nZWAg.jpg




again, seat the plate on the pins of the new link using your fancy chain tool.

http://i.imgur.com/SSY1g.jpg




now, reconfigure your fancy chain tool to the crimping anvil.

http://i.imgur.com/H5KN7.jpg




rotate the crank so that the chain is off of the sprocket. seat the tool so that the anvil is centered over one of the pins.

http://i.imgur.com/YyOOa.jpg

http://i.imgur.com/358tH.jpg




now take a few turns on the wrench. here, you can see the top pin is riveted, while the bottom pin is not. this was the result of two 1/4 turns of the wrench compressing the anvil of the chain tool.

http://i.imgur.com/OMB2d.jpg




for comparison, here the bottom pin shows what one 1/4 turn of the wrench looks like.

http://i.imgur.com/dDcEU.jpg



and here's two 1/4 turns on the bottom pin. notice that it isn't quite as riveted as the top pin. I assume this is the result of interrupting one 1/4 turn from another.

http://i.imgur.com/fT8S6.jpg

As good as that thread reference Number ONE is on the subject...
it still includes a sentence which is directly contradicted BY THE FSM...
specifically ....

"The second method consists of aligning marks on the front cam bearing tower and the sprocket thrust washer. This method can give you an accurate reading but it all depends on how accurate the marks are aligned."
THAT method is only for original build of the engine.... and only to get things ' in the correct quadrant'... not anywhere near accurate for anything later...

Too bad the OM60x engines have no lower oil pan for such inspections and to replace from parking lot transition mishaps. You have to greatly lift or pull the engine to change the pan, and the part is expensive.

Considering that these could crack on high mileage engines, most all of them on the road by now, Does anyone know if these can successfully be changed on OM60x engines from the little rectangular side cover? With the sound encapsulation panels off the side cover and bolts are free and clear in plain view with access room.

As these engines age a cheap plastic or rubber part will usually be the end of them from simply age, but not miles. These car's faithful high mileage ability will certainly be limited to brittle plastic and expensive diesel fuel instead of the use of hardened parts, quality forged metals, coatings, craftsmanship, engineering, and machining tolerances.

I vote for replacing brittle plastic as preventative maintenance if possible.

Excellent thread with great detail! I'm about to do the same job on my 300SD, and this will be a great help.