The crank shaft arrives today from Germany for my OM603 engine. Need some hand holding on the how to replace the crank in the most efficient manner. Basically, the crank shaft broke near cylinder 1 and it is the only problem. I drove for 20 miles to get home and the car was parked ever since. The engine was noisy and leaking oil from the front seal ( the broken shaft moved in and out a bit ), apart from that it drove fine. So the engine is sound. Question, what are the rough steps to replace the crank? Please list the steps and any pitfalls, if any. I have never done this kind of engine work. Thanks.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Step 1) - Remove engine from car.

Step 2) - Take engine and new shaft to competent engine repair shop.

Step 3) - When new shaft has been installed, replace engine in car.

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Jim

Well, that is can't go wrong advice.

Do you know why the crank broke? I've never heard of a mb crank breaking before.

To do it correctly you will have to remove the cam chain as a minimum. At that point it makes sense to replace all the cam chain guides. Removing the crank without removing the head will be very tricky to say the least but it might be possible. I'd think going through the engine and replacing whatever is deficient would be a good idea.

Did you try to find a known good used engine?

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Shall I take the car to the shop as well. Why bother to remove engine myself?

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Truly, the better solution.

Prior to this the oil chain snapped and engine seized. The #1 piston journal of the crank was oval'ed by the rod bearings. I rehab'ed the engine but I did not machine the journal. I drove the car for another 15K and then the crank snapped near the oval'ed journal. I am pretty sure that was the reason and there is nothing wrong with the rest of the engine. I could replace the engine but I give myself a more challenging task . Basically I do not know what I am getting into but I will give it a shot. The worst is to replace the engine later, nothing to lose but my time.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Seems like there is a good possibility of a lot more damage than just the crank.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

How did it stay running? Did it break in front of the timing gears. Or did a rod let go.


Sent from my iPad using Tapatalk Pro

I could have laughed at '( the broken shaft moved in and out a bit ), apart from that it drove fine. So the engine is sound.' but the impact of reading a tragedy never amused me.

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84 300SD
85 380SE
83 528e
95 318ic

It broke after the timing gears. It did run after the crank snapped. It broke near the 1st piston but all timing gear still turns. It was pointed out to me that the engine sounded very noisy and oil dripped out. I did not even notice it myself, I was doing 70 mph on the freeway to get home. The guy who noticed it told me try not to stop on the way home. The reason of the oil leak is the front seal is not sealing the 'vibrating' crank. I removed the oil pan and 1st rod bearing. I looked very very hard around the front of the crank before I saw the hairline crack . I was thinking about welding it back and mickey mouse the job until I saw a crank shaft for sale on eBay for cheap. So I decide to do a 'better' job. I may change the timing chain and a few plastic guides along the way but that is about it.

The car has been sitting for a few months and I schedule a year to put it back together. The car is rust free CA car so it is worth fixing. If the worst come to the worst then I can source an engine or just donating it. No sarcastic comments please. Anyone has any idea/good steps to offer for an engine novice? I just want some rough steps on replacing the crank with the engine removed. Some dos and don'ts and the minimum parts removal to access the crank and do the job. btw: I have the OM603 engine FSM.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

I don't have any tips but whenever I tackle a big job I follow the factory service manual step by step. Or try to find a good online tutorial. Most people, if pulling the motor for a crank would probably just go through the whole engine.

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Brian
87 300Dturbo 180K #14 head still running R-12 SOLD 12/2017
02 F350 Powerstroke 180K
05 Chevy Express 1 ton w/Royal Utility box 120K
08 Infiniti FX-35 40K
15 Golf Sportwagen TDI 35K
10 Sprinter 3500 chassis with a Class A Winnebago on it. 56K

Thankfully I just avoided this kind of repair.

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-“Never trust a mechanic who drives new cars. They're either charging too much money for their work, or they can't keep an old car running - maybe both.”

Why not do "the best" job?

Fix it once.
Fix it right.
Drive More.
Worry less.

This isn't sarcasm... I honestly want to understand the logic.

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1991 300D 2.5 "Rocinante"
2002 Golf TDI "Teen Spirit"
--------------------
1984 300D
1966 Mustang I6 3sp
1985 Mazda RX-7 GSLSE
1982 Toyota Supra
1977 Datsun 280z
1971 Datsun 240z

Add me to this list. If the journal was ovalled due to oil pump failure and crank seizure, it seems like there would be more collateral damage to the engine than just ONE area. Since it ran that way for 15K afterwards and then ran at highway speeds on a return trip home with a broken crank I'd expect there to be other hidden goodies waiting to ruin your day once the new crank goes in.

I'd be personally drawing the line on this engine and sourcing a good 2nd hand one. If the engine were truly special, it'd be sent off to an engine rebuilder and gone through since it's being taken down that far, but 603's aren't really anything special all things considered.

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Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)