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#1
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Quote:
![]() Now, go back to the photo in post #30. You have a red mark in that photo that you, apparently, believe is relevant to some timing mark. It's not. What is necessary to know, is the reading on the crankshaft damper over to the left........by that filthy dirty bracket. The straight edge of the bracket will provide the point of the crankshaft position. Just so we know exactly where you are, please clean off the crankshaft damper so that we can read the numbers and take another photo of the bracket and the numbers. It would be preferable if you clean off the bracket as well. I'm not convinced that you're anywhere near 30° off because the engine won't rotate under this condition. So, until we know exactly where this engine is, we can't go forward. |
#2
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I replaced the chain in an OM603 and M103 by myself without special tools other than zip ties so it can be done. I have a big 'learning' account so I'm not afraid to mess up
![]() If I understand this saga, the chain is still apart and the tensioner is off. If so, I don't trust any of the alignment readings. The reading I'd trust most would be taken by holding the cam sprocket steady and turning the crank sprocket CW as far as it will go. From what I remember rolling in a new chain is not a 'linear' process. The IP or vacuum pump will cause that sprocket to act like a capacitor. You'll turn the crank seemingly forever with no corresponding movement of the cam then 6" of chain will get sucked in. Freaky! However, it is precisely this behavior that lets you manage the task by yourself. Once you figure out the timing, no pun intended, you'll realize that you don't need constant tension on the new chain (I have it pull itself out of a can of oil) or the old chain (I let is dangle out towards the water pump). If you've ever had the vacuum pump off, you'll know there's no way the chain is coming off the timer. When I pulled the IP off the SDL I left the timer in the chain. I put some zip ties for good measure. It's a chore to get the timer off the chain. You have to slip a shield between the timer and the chain as you slacken the chain from cam. Some line the cavity with grease so the chain sticks to the walls. My 2 cents - there's no way the chain came off the crank or IP timer. If you're sure the chain didn't come off the cam, I'm sure cam timing is how it was before your neighbor left for his trip. 2 cents doesn't fix many bent valves :/ Sixto 93 300SD |
#3
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Brian,
I can see the crankshaft damper, I tried taking a picture, but it's nearly impossible to get a camera in there. But I can assure you the straight edge of the bracket is about an inch to the left of the begining of the lines stamped on the crank pulley. I can see a number 20, then I see a number 10. I am assuming the TD is hidden by the belt tesioner. Then on the other side I can see the numbers go up to 40. And I also know that this is almost the same position it was at prior to taking the chain off, based on what I thought at the time was the marking (but now think is some kind of balancer glued to the pulley). The engine turns pretty smooth, but does come to a point where I can't turn it, but if I let off of it, then go back to turning it continues to turn smooth again.
__________________
87 300D - Running on Veggie oil; 260,000 plus miles; Original #14 head ![]() |
#4
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Ok, I've got to get this car put back together today, so I need to know how to get everything lined up properly. If I turn it over so the crank is at TDC, and take out the tensioner, then all I need to do is get the cam at TDC right? And from what I've been reading, the IP timing can't really get "off", unless it skipped a tooth on the sprocket, but it doesn't seem like that's a possibility. SO, I guess all I need to figure out is how to get the cam back on TDC the proper way. Can anyone guide me through this? Also, I turned the engine over 2 more times to make sure that it really is off as much as it was last night, and it still is. With the stamped line on the cam gear matched up to the line stamped on the tower, it is at about 40 which is before TDC.
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87 300D - Running on Veggie oil; 260,000 plus miles; Original #14 head ![]() |
#5
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I am thinking that I might just get the cam to TDC, then undo the chain at the cam, pull it off, then turn the crank ccw till it's at TDC, then put the chain back together. This should work, right?? I'll make sure to turn it clockwise afterward to make sure it is righ. The only problem is that the master link is no longer at the cam TDC, maybe I can turn it some more till it lines up at TDC again.
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87 300D - Running on Veggie oil; 260,000 plus miles; Original #14 head ![]() |
#6
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I think you'll be turning the crank for some time to get the master link back on TDC. When I marked my chain and gear and then spun around a few times, the mark on the chain was never again in alignment.
Are you sure your at 0|T on the crankshaft as per Brian's clean up the tab and wheel so we can see the marks clearly? If you can spin engine freely with that much advance/retard on the cam something is fishy. I also think that spinning the engine without the cam in is kinda risky. It'll be a 2 man job since someone will need to keep some semblance of tension in there. I think the better approach is get the engine to TDC, then pull cam (you will need to remove cam gear to make this work). Rather than following FSM cam removal untorquing sequence you will have to untorque ALL towers in the sequence mentioned because it is based on the cam being at TDC and there's pressure on different lobes of the cam 40 degrees away. You won't know which order to do it, so only foolproof way is to loosen all in parallel with each other. Once cam and gear are off you can reset the cam to line up the marks on the cam tower. Do not loosen cam gear until you are at crank TDC otherwise you'll have movement issues where crank will move, cam will not. Even after doing this, the IP timing is not certain.
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1982 300TD 210K miles ("The Replacement" aka "The Anvil") - SOLD 1979 300SD 245K miles (never ending project) 2007 Pinarello F3:13 1995 Ducati 916 (SOLD, sniff) 1999 Ducati 900SSie (SOLD) |
#7
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Yeah, I think BC and I are in agreement. On the 603 I haven't experienced the cam wanting to slide backwards. Woodruff key absolutely. it's a tricky little guy.
While there may be enough slack in the chain to move link by link, still need to take off the cam towers, otherwise spinning cam will be impossible by hand (or becomes two man job, one pushes chain, other turns cam with wrench)
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1982 300TD 210K miles ("The Replacement" aka "The Anvil") - SOLD 1979 300SD 245K miles (never ending project) 2007 Pinarello F3:13 1995 Ducati 916 (SOLD, sniff) 1999 Ducati 900SSie (SOLD) |
#8
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Then, check the cam marks. Most likely they will not be aligned. If they are close to 180 degrees apart, then turn the crankshaft one full turn back to 0 degrees. They should be within 20 degrees of each other. If they are not within 20 degrees, do not continue with this procedure. Remove the tensioner and see if you can get enough slack in the chain to "roll" it over the teeth of the camshaft. You'll need to bunch it upward in one place and, effectively gain one tooth by moving the bunch in a circle around the top of the sprocket. I'm not sure if there is sufficient slack to do this, but, it's preferable to removing the sprocket. If you're not successful, then you need to remove the cam sprocket. Be careful with this. It also presents more possibilites for FUBAR. Understand the following carefully: 1) The camshaft wants to slide rearward. The sprocket prevents this. So, you should definitely block the cam behind #6 to prevent this from occurring. 2) The sprocket has a thrust washer sitting right behind it and it has a Woodruff key that is pressed into the camshaft. Both of these items may desire to go into the abyss. Your job, Jmana, should you decide to accept it, is to prevent that from happening. Good luck Jmana. If you are caught or killed, the Secretary will disavow any knowledge of your actions. ![]() |
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