Not the greatest day ever. (crank pulley) - PeachParts Mercedes-Benz Forum

SirNik84 · #1 02-21-2014, 01:34 AM

On my way home from work my steering got heavy, my charge light comes on and my temp starts going up. Aww crap, I just knew my main pulley was no longer functioning. Yep, the engine was on but the pulley was not spinning. The crank bolt was finger tight. I was stuck on the side of the road until iwrock came along with his friend and a 27mm socket. Got the bolt tight and limped the car home. This is what I discovered once I was home.

Thank god there seems to be no serious damage to the crank or pulley, the dowel pins seem to have taken the brunt of the damage.

For the record I was the one who installed the ballencer/pulley last, over 3 years ago, so this is on me.

Diesel911 · #2 02-21-2014, 02:16 AM

Boy, this is going to be quite a project for you.

If you decide to go with oversized Dowel Pins I think you will need to get the Engine at TDC and make sure the Pulley and the Pointer also point to TDC.

What is the speculation as to the reason for the Failure.

No proof but I think if an Engine is shaking abnormally and the Injectors or Cylinder Compression is not balanced with in specs it causes the Crankshaft Vibration to be more than the Damper can take care of.

I have never had to do the Dow Pin Job but are the Original Dowel Pins Hardened or are they somewhere in-between like a Grade 5 Bolt would be?

Can't tell from the Pic. What do the threads look like inside.

In the past I have always degreased the parts with Brake Cleaner or clean Solvent, let them dry an used Loctite on Crank Shaft End Bolts.
It is a bit of a pain to remove them later but if you heat the Bolt a bit with a Propane Torch to melt the Loctite which is kind of a Plastic you can remove the Bolt without much more trouble that if you did not use the Loctite.

whunter · #3 02-21-2014, 03:14 AM

Diesel Harmonic Balancer threads
Diesel Harmonic Balancer threads - PeachParts Mercedes ShopForum

Main seal front/rear and harmonic balancer + Pulley
Main seal front/rear and harmonic balancer + Pulley - PeachParts Mercedes ShopForum

.

SirNik84 · #4 02-21-2014, 12:13 PM

The threads on the bolt look ok. I can't tell how well the threads on the crank fared. I bought a m18x1.5 tap to clean the threads out. I think the crank is ok. The pins sheered, so I'm guessing they are softer then the crank and pulley. iwrock had an E55 and was telling me its common for those guys to go to over sized dowel pins. I haven't had a chance to get a good look at it in the daylight, but if the crank is ok, and the balancer is ok I'll just replace the dowel pins.

Cause of the failure, I'm pretty sure the bolt came loose. I'm not 100% sure on the torque spec, but I looked it up when I installed the balancer 3 years ago, and it was past any torque wrench I could get my hands on. I think it was 300 ft/lbs. I'm sure its posted in one of those links whunter posted, I'll be looking in a moment. I called my friend who worked at the local asphalt plant, he got the biggest tools I know of. He called on of his friends and he located me a torque wrench good up to 600ft/lbs. I'm hoping with the correct torque (and loctite

) I will never have this problem again.

I'm not sure why it took 3 years for the bolt to come loose. But, its one of those things, I knew I didn't do it buy the book, so I've been waiting for it to come bite me in the rear end.

SirNik84 · #5 02-21-2014, 12:18 PM

whunter has the torque spec. posting here for the record.

Quote:

Originally Posted by whunter

Mount the three cup springs (washers) with the crown (raised dome) toward bolt head.

The harmonic balancer is secured to the crankshaft by a single 18mm X 45 mm bolt torqued to 270 - 330 Nm = 200-244 ft. lbs.

Some day I'm going to need to buy this man a beer IRL!

ROLLGUY · #6 02-21-2014, 12:28 PM

I am glad to see the crank was not damaged. That would turn into a real bummer if it was. BTW, how is the progress on your mom's car? We have not heard much lately.....Rich

SirNik84 · #7 02-21-2014, 12:38 PM

I just sent you a PM with some pics! lol. Moms car is doing better then mine at this point

I was seriously freaking out the whole drive home after knowing the pulley had spun. I've seen the damage the crank can take first hand. When I got the pulley off and there wasn't serious damage it felt like a weight was lifted. I've got my dads 88 ford diesel in my drive way for an engine swap. My dad and I started to rewire my garage last weekend... the last thing I need is a major repair on the car that takes me to work. luckily I bought my sisters Civic a while back as an emergency escape pod, so I can take my time repairing the SD without to much stress and drive the pod to work.

iwrock · #8 02-21-2014, 12:55 PM

Some fun videos!

OM617 spinning without turning the crank pulley. - YouTube

Aftermath of the broken dowel pins - YouTube

SirNik was lucky here!

Here's some threads about repinning the E55 crank:

******How do you pin a W211 E55 crank with it still in the motor, come on in****** - MBWorld.org Forums

BIP Pin Kit/Crank Repair - MBWorld.org Forums

SirNik84 · #9 03-02-2014, 10:40 PM

I got my new parts form the dealer, new bolt, dowle pins, washers, front seal. I then cleaned everything, ran a bottoming tap through the crank thread, and went to work. I got the front seal installed, balancer back on, dowle pins installed, got the bolt tightened as much as I could with my large ratchet. I was moving the whole car with my friend in the driver seat pressing the brakes.

That got us thinking. we pulled the bolt out, and cleaned the loctite out of the threads in the crank again. Chased the new bolt with a die to clean it up. Then went to work making our "wrench" to hold the engine. Being the horder I am, I had a spare set of pullies. I got the balancer ring off of that and welded a bar to it. thats when I discovered its really 2 parts with rubber between them, not only that but the middle section is aluminum. So after welding the bar to the balencing ring, we put 2 grade 8 bolts through it to hold it solid. We aligned the bolts with the notches in the harminic balancer so we could bolt it solid to the harminic balancer.

Here is a picture of the "wrench" and the balancer we used for mock-up.

I got the wrench bolted to the balancer, but one of the treads for the 6 smaller bolts wouldn't go in. I left it out and went ahead witht he torquing. My neighbor, who helped me build the wrench, brought home a 200-600ft/lb snap-on torque wrench. Here is a close up shot of the wrench installed and us torquing the bolt.

and DONE!

I searched the forum before building the wrench, but I have never seen this done before, or even how y'all held the motor while appling the the required torque. Figured y'all would enjoy my solution to the problem.

Oh, and the 6th bolt, the threads were just dirty, a little brake clean in there and they all thread in.

I didn't get further then this today, because about 10 min after we got it torqued it started dumping rain on us. I had just enough time to get the valve cover back on and tools picked up Perfect Timing. CA need the rain! It was a good day.

Bio240D · #10 03-02-2014, 11:00 PM

Nicely Done SirNik!!
I love how you squeezed that intercooler in there! I would do that on my 240 if i didn't have the air filter right there!
Cheers!
Chris

SirNik84 · #11 03-02-2014, 11:10 PM

Some time ago I decided to take advantage of the w126 dual firewall. I moved the battery to the trunk, air cleaner to the batteries old home, and put the intercooler in there. I'm pretty sure it does nothing. I was going to delet the fog lights out of my US spec lights and make an air intake for it. But then I got euro lights, so its got pretty much no flow. I want to ad a fan to it, but haven't done that yet. I put a basic water injection system on the engine that I pieced together from ebay parts. It does more for me then the intercooler. but the intercooler was fun to build and looks cool

ROLLGUY · #12 03-02-2014, 11:48 PM

Now you can offer the tool through the tool rental program.....Rich

tangofox007 · #13 03-02-2014, 11:49 PM

Quote:

Originally Posted by SirNik84

I searched the forum before building the wrench, but I have never seen this done before, or even how y'all held the motor while appling the the required torque.

Following the FSM procedure would have been way easier. It basically calls for jamming the balancing disc with a chisel or extension bar. That makes it a one-man evolution.

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