Replacing chain guides on M272 / M273 without removing cylinder head
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Joined: Feb 2020
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From: Woippy, Lorraine, France
2005 S 350 L W221 (1637th produced), 1981 300 GD and 1985 280 SEL in restoration
Replacing chain guides on M272 / M273 without removing cylinder head
Hello everyone,
Due to a bad balance shaft pinion, my M272 is in pieces. The chain guides were also in pieces, so I thought that I should replace them. They were so broken that, having a hard time getting them out, I thought, frick it, I'll just break them the rest of the way to get them out.
Now I am facing an issue. They are HAAAARD as hell to get back in, and some barely impossible. I was able to do the bottom right by sliding the pin bolts in the guides then wiggling it all on, but all others are impossible to get in straight. The WIS repair manual says that the heads need to come off, but having already spent more than 3000 € on parts for this car, I do not want to buy new head gaskets and headbolts as the ones on here are perfectly fine, and I need to get this car to work again, it has been 3 months since the engine came out.
If anyone could help me it would be very precious. Thank you very much
Due to a bad balance shaft pinion, my M272 is in pieces. The chain guides were also in pieces, so I thought that I should replace them. They were so broken that, having a hard time getting them out, I thought, frick it, I'll just break them the rest of the way to get them out.
Now I am facing an issue. They are HAAAARD as hell to get back in, and some barely impossible. I was able to do the bottom right by sliding the pin bolts in the guides then wiggling it all on, but all others are impossible to get in straight. The WIS repair manual says that the heads need to come off, but having already spent more than 3000 € on parts for this car, I do not want to buy new head gaskets and headbolts as the ones on here are perfectly fine, and I need to get this car to work again, it has been 3 months since the engine came out.
If anyone could help me it would be very precious. Thank you very much
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This place is a joke.
At this point in time, m272 balance shafts should not be replaced, unless it's an extremely low mileage engine, used engines are so cheap ($1000) it doesn't make any time or money sense. Are things different on your side of the pond? Anyhow I've seen plenty of people screw up the head gaskets when reinstalling the timing cover. I'd check the price of new head gaskets and bolts and maybe just pull the heads.
From another forum,there may be a way:
https://www.benzworld.org/threads/m272-m273-engine-timing-case-and-guide-pin-removal.3086837/
From another forum,there may be a way:
https://www.benzworld.org/threads/m272-m273-engine-timing-case-and-guide-pin-removal.3086837/
Last edited by E55Greasemonkey; May 17, 2023 at 08:50 PM.
Thread Starter
Member
Joined: Feb 2020
Posts: 101
Likes: 13
From: Woippy, Lorraine, France
2005 S 350 L W221 (1637th produced), 1981 300 GD and 1985 280 SEL in restoration
I want to keep the car forever, so I prefer doing it and not having it fail again. If I source even a 100'000 km M272 which is very rare and costs upward of 2000€, I'll have to do it in another 100 to 200'000 km, so it's not worth it. I prefer eliminating the problem than postponing it, as that car will definitely go over a million km. I plan on someday making a trip around the world with it, through Russia to Asia, then back to Russia to Alaska then Canada, USA, Mexico, South America and back home. Plus I go each summer to vacation in Bulgaria and I drive quite a few thousand km per month, so if I replaced the engine I'd have to do it again next year or so.
I saw that thread earlier. I think I will pull the heads off. If you say there's a risk of damaging the head gasket, I'll pull the heads off, even if it means I need to wait a bit to buy the parts. At least the engine will get a 100% overhaul, as if I pull the heads, while I'm in here I should also do the piston rings and rod bearings. I have a W220 I planned to sell once my 221 is finished but it looks like I'll have to sell it before lol
I saw that thread earlier. I think I will pull the heads off. If you say there's a risk of damaging the head gasket, I'll pull the heads off, even if it means I need to wait a bit to buy the parts. At least the engine will get a 100% overhaul, as if I pull the heads, while I'm in here I should also do the piston rings and rod bearings. I have a W220 I planned to sell once my 221 is finished but it looks like I'll have to sell it before lol
Thread Starter
Member
Joined: Feb 2020
Posts: 101
Likes: 13
From: Woippy, Lorraine, France
2005 S 350 L W221 (1637th produced), 1981 300 GD and 1985 280 SEL in restoration
By the way, I am having trouble finding the correct part number for the head bolts. It is absolutely needed to replace them if they're in good condition or not?
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From: Orbiting the planet
This place is a joke.
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