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W209 engine 272 Balance Shaft Access/Removal

7K views 6 replies 3 participants last post by  rudeney 
#1 ·
My balance shaft gear on my W209 does not have any issues. Checking the engine compartment and there seems to be plenty of room to service the timing chain and access to the balance shaft gear if needed (removal of Radiator) without engine removal. Also checked the Star Service Library Disk and it appeared the servicing would not be any more complicated than any other vehicle.

I must be missing some information that makes this repair very complex. Can this gear be removed with a standard puller?
 
#3 ·
My guess is that you are either confusing this with the "harmonic balancer" which is an external bolt-on pulley, or you are confusing the job with the removable timing gear on the M273 V8 engine. The defective timing gear on the M272 V6 engine is a forged part of the balance shaft and that runs the full depth of the engine block, parallel to the driveshaft. It cannot be removed without pulling the engine out of the vehicle.
 
#7 ·
I don't believe you will be able to tilt the engine up enough to do this. Besides that, if you get to the point where you could do that, you might as well just take it out and make it easy on yourself. In fact, on the V8, most mechanics go ahead and pull the engine out even though they don't have to. The defective gear is just bolted to the crankshaft so all they need to do is remove the timing case cover for access. But to do that, the oil pan has to come off, and that requires lifting the engine several inches to clear the cross brace. Getting to the point where the engine can be lifted means everything has the be disconnected (exhaust pipes, accessories, etc.) just as if you were going to pull it out, so they typically go ahead and do that.

But still, why go to all of that trouble if yours isn't failing? The symptoms of failure are very clear - the MIL will illuminate and you'll have DTCs 1200 and 1208 (OBDII codes P0017 and P0016). Even though there are several reports of failure here on the forums, I really don't think it's a rampant problem. Yours might go 200K miles with no problems. It might get stolen, totaled or sold before it ever has a problem.

The root cause is improper processes during manufacturing of the balance shaft/timing gear. I wrote long dissertation about this (http://www.benzworld.org/forums/w20...ne-ever-had-replace-their-12.html#post5432899). Basically my idea is that not all of the parts are defective, but since MBZ can't ties specific defective parts from the supplier to specific VINs, they list the entire 500K+ range. That's also why I think they didn't do a formal recall - they knew only a small percentage will fail, so they handle them individually.
 
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