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vibration damper Failure 300D

2K views 2 replies 2 participants last post by  Earl.Allen 
#1 ·
Just had the aluminum vibration damper plate come off while driving slowly. Fortunately I was only a mile from home. Two screws were completely unscrewed of their own accord and floating around in the pulley mouth. The other three were completely sheared. My only guess is that the damper had lost balance and ripped itself off? Astoundingly, no damage was done to any of the the surrounding components. There was no loud bang, no noise that I could discern. My first indication that something wasn't right was when the brake and pad wear light came on at the instrument cluster indicating the alternator was not charging. The temperature rapidly climbed a few seconds later.

How common is this? I am almost concerned that someone tried to steal the part and had unscrewed two of the bolts. All 5 bolts were still contained in the mouth of the pulley. Two had come completely un-threaded somehow, while the other three were sheared off.

Any thoughts?

Anyone recommend a place to purchase a new harmonic balancer and vibration damper?

Found a few other sites talking about this, but personally, never heard of this happening.

<\\http://www.peachparts.com/shopforum/diesel-discussion/29387-haromonic-balancer-note-caution.html#post158104\>

"According to the official M-B manual, the US model of the 300D has an aluminum vibration damper plate sandwiched between the belt pulley and the harmonic balancer (or balance plate as M-B calls it). The damper plate and belt pulley are connected to the harmonic balancer by 6, 8mm x 65mm hex head bolts. The 240D does not have the vibration damper plate. Engtawork is correct that the harmonic balancer for the 240D and the 300D is secured to the crankshaft by a single 18mm X 45 mm bolt torqued to 270- 330 Nm or 200-244 ft. lbs. Engtawork also makes a good suggestion in properly torquing the 6 bolts (35 Nm or 26 ft. lbs.) holding the pulley and vibration damper to the harmonic balancer (I did not use thread locker because the bolts have the spring-type lock washer, but that is up to the installer and a bit of insurance so long as it is not the permanent thread lock formula)."

Cheers,
Werner J Stiegler
 
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#2 · (Edited)
edit:
to answer my own question:

"Ok. I am a pain in the butt or whatever someone may call me for not going ahead and helicoiling the old counterweight. But since replacing the assembly by one bolt is easier than helicoil for six bolts I called MB USA and left a message for an engineer to call me.

The engineer at MB USA returned my call promptly and said that I could remove the counterweight from the salvage car and bolt it to my crankshaft without any problem whatsoever. He said as long as it came from the same engine there would be no risk of damage whatsoever.

I am not saying anyone on the forum is wrong about how to repair this problem, but it seems that the shop forman at the dealership and the MB USA engineer who spoke with a German accent by the way both say otherwise.

Just thought I would include this NOT to criticize anyone for how they would fix it, but just in case someone else has the same problem.

PS - you can't put the vibration dampener on the wrong way. It has two holes drilled in the plate for timing marks. Besides, the parts yard left the pully, dampener and balancer all assembled and removed them by the center bolt to the crankshaft. I'll be darned if I am going to disassemble them. I am just going to TopDeadCenter the engine and bolt the thing on properly and torque it."

-from a peach parts posting (user "willrev").
http://www.peachparts.com/shopforum...l-off-help-i-may-call-quits-1982-300sd-4.html


Previous question:

Well, after reading several postings about this, it appears the counter weight and vibration damper are balanced together and matched to the crank shaft. This does not bode well for trying to replace the aluminum damper which got chewed up when it came off. Anybody know how to approach this? There must be a way to re-balance this stuff.

Cheers,
Werner J Stiegler
 
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