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Old 06-06-2007, 10:04 AM
emerydc8 emerydc8 is offline
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Join Date: May 2007
Location: Arizona
Posts: 757
I just went through this to change the water pump on my 1993 400E. The shop forum at the dealer suggested that I could "walk" the balancer off once I took the 6 bolts out. But it turned out that I had to take the 27 mm center bolt out in order to get the damper off.

In order to loosen the bolt, though, I had to figure out how to lock the crank up so it wouldn't turn counter clockwise when I turned the bolt. The forman showed me how they did it at the dealer. They didn't use the crank lock tool that is specified in the manual. They simply opened the access plate on the bottom of the bell housing and turned the crank clockwise (while facing the engine) until they could see one of the three torque converter bolts. Then, they pulled out one of the bolts and replaced it with a longer bolt that had a sleeve on it. See the picture. You can get the bolt and sleeve at Ace hardware, but make sure you get the hardest bolt they have.

Also, the torque required to get that bolt off is very high. In fact, the forman told me that the shop's torque wrench only went up to 250 lbs, so when they reinstalled it, they would go to the 250 lbs then add a quarter turn to it. He said the MB shop manual used to have that procedure in it but they took it out. I used a floor jack under the breaker bar to loosen the bolt and it nearly lifted the engine off the mounts.

The forman suggested that if I disturb the crank bolt that I should also replace the front main seal. They loaned me the tools to pull off the hub that goes around the crank. There is also a two-sided tool for installing the seal (one side pushes the seal back further than the other side, in case there are running scores where the main seal sits.

Be careful that you don't turn the engine counter clockwise. At least on the 119 engine, the forman said the timing chain tensioner only works in one direction and you might kink the chain if you're not careful.

Hope this helps. I'm sure there are others who are real mechanics that can add to this.
Attached Thumbnails
1989 560 Sel Water Pump Need Help-balancerbolt.jpg   1989 560 Sel Water Pump Need Help-crankshaft.jpg   1989 560 Sel Water Pump Need Help-cranksleeve.jpg   1989 560 Sel Water Pump Need Help-crankhousing.jpg   1989 560 Sel Water Pump Need Help-cranklocksub.jpg  

1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles

Last edited by emerydc8; 03-08-2009 at 05:21 AM.
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