front pulley fell off... CHECK YOUR BOLTS - PeachParts Mercedes-Benz Forum

rg2098 · #1 01-18-2007, 11:22 PM

Took the day off yesterday and went down to the Auto Show downtown Detroit. Right in front of Comerica Park and Ford Field the front main pulley sheered off the crank. 5 hours later I got to whunters home stopping every 1.5-2 miles to let the engine cool off (no water pump). I drove through some really scary areas of Detroit let me tell you.

Lesson, check the 6 bolts that hold on that pulley. You might be glad you did. Thankfully the pulley didn't damage anything and it's costing me a headache and 6 bolts.

Monomer · #2 01-19-2007, 12:32 AM

I was also at the autoshow yeasterday. First time seeing an SLR in person. Amazing

I drove my 124 there. I'll be sure to give a good cheack under the hood sometime soon.

unkl300d · #3 01-19-2007, 12:33 AM

Thanks for the heads up. I had read about this in a service bulletin put out by one of those online recall info websites.

pawoSD · #4 01-19-2007, 01:50 AM

So far so good on our cars....we drove the '83 310 miles round trip to the autoshow with 5 people in it last Saturday, it did fine.

(280k on it)

I really enjoyed the show, and got to sit in THREE diesels!

E,R,ML I think I would take the ML cdi, I was drooling. E would be ok too though

We managed to hack two 4-Matic Logos out of the ice wall!

Johnhef · #5 01-19-2007, 07:59 AM

My friend got his 300SD this way. The crank bolts sheared off on the previous owner when the a/c compressor seized.

pawoSD · #6 01-19-2007, 08:11 AM

Quote:

Originally Posted by Johnhef

My friend got his 300SD this way. The crank bolts sheared off on the previous owner when the a/c compressor seized.

My dad's '83 had that happen, but it smoked the A/C compressor clutch (big cloud of smoke), and melted the belt....crank was undamaged.

Stevo · #7 01-19-2007, 10:28 AM

It happened too me a few years ago, actually my daughter was coming home from a movie with the 78 240D. By the time I got there she had beat the bushes along the road and found the pulley. Yah, check those allens.

Ether · #8 01-19-2007, 11:03 AM

Happened to me a couple of weeks ago as I was trying to head down to Orlando. Going 75 mph in the left lane when I felt the clunk!

I was able to get off to the side and nurse it to the next exit. I was 120 miles from home so my wife came and got me and I had to return the next day with a trailer to haul the old boy back home.

tangofox007 · #9 01-19-2007, 12:16 PM

Quote:

Originally Posted by rg2098

Lesson, check the 6 bolts that hold on that pulley. You might be glad you did.

If the third digit in you model year is less than nine, I would recommend replacing those bolts on principle. On the 617 engine, the bolts are standard metric hardware (socket head cap screws); no need to buy them at the dealer.

Brian Carlton · #10 01-19-2007, 12:28 PM

Quote:

Originally Posted by tangofox007

If the third digit in you model year is less than nine, I would recommend replacing those bolts on principle. On the 617 engine, the bolts are standard metric hardware (socket head cap screws); no need to buy them at the dealer.

Any idea what's happening there?

Do they fatigue and shear.........or do they simply loosen??

What's required to access them?

vstech · #11 01-19-2007, 12:53 PM

Quote:

Originally Posted by Brian Carlton

Any idea what's happening there?

Do they fatigue and shear.........or do they simply loosen??

What's required to access them?

of the posts I have read on this problem, it looks like they loosen first, then the vibration/stress causes them to shear.
sounds like a good coat of blue loctitie would be prudent there.
John

pawoSD · #12 01-19-2007, 01:00 PM

Why would they just all the sudden loosen after 200,000+ miles....but were fine all along before that? There must be something else at that point that influences or causes the issue to occur. Many people on here have had these engines (or have presently) with 300,000+ on them with no event like that ever taking place. Maybe its just a flaw that presents itself on *some* engines rather than a common failure for all. We should have a poll that asks how many people have actually had it happen....Adam's is only the 2nd or 3rd occurrence I can remember in my whole time of being on this forum....and there must be hundreds of these cars amongst all of us....so thats a very small percentage.

tangofox007 · #13 01-19-2007, 01:17 PM

Quote:

Originally Posted by pawoSD

Adam's is only the 2nd or 3rd occurrence I can remember in my whole time of being on this forum....and there must be hundreds of these cars amongst all of us....so thats a very small percentage.

I count five occurences on this thread alone!!!

Ether · #14 01-19-2007, 01:17 PM

In my case I don't believe it was due to loose bolts.

As a matter of fact I'm pretty dang sure that they were not loose since all 6 holes still had what was left of the bolts in there and they had to be drilled out in order to get the puller attached so that the harmonic balancer could be removed.

There is a spacer plate (don't recall the proper name) between the balancer and the pulley. It's actually 2 pieces that are joined by a rubber piece. This rubber piece was cracked and we theorized that this may have been the cause of the imbalance and thus what led to its ultimate doom.

pawoSD · #15 01-19-2007, 01:25 PM

Quote:

Originally Posted by tangofox007

I count five occurences on this thread alone!!!

Is there any way to tell beforehand if its going to happen? Or is this spontaneous?