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Crankshaft pulley fell off...Is my crankshaft still reusable?
So I went to go drive my car yesterday and as I was down the street from my house my power steering went out and the battery light came on. I turned around and headed back to the house and popped the hood to discover that my crankshaft pulley was laying at the bottom of the car covered in oil and the serpentine belt was tangled up. After moving some hoses and finally getting to the crank pulley, I found that the previous owner had failed to mention that he had a Evosport pulley installed on the car. My guess is that the pulley was not torqued down correctly when installed but held just enough when driving with the stock belt. Most likely the extra tension from me installing the supercharger made the pulley finally give way, and snapped the woodruff key along with it.
My question is that will I have to replace the crankshaft with the minor damage the pulley did to the shaft or could I just removed the broke woodruff key and replace a new one with the OEM crankshaft pulley? I'm really hoping that I won't have to have the motor pulled and replace the entire shaft as this is a very expensive repair job to do. Please let me know if you guys can help or give me some advice. It would be greatly appreciated.
As far as the crank goes, from the pics it looks like just a little effort with some emory cloth should polish that up and you'd be fine.... my overwhelming question though is where in the hell did all that oil come from? Did it damage the timing set seal? THAT is what would be my immediate concern......
Sucks
Where did the oil come from?
If the pully fits properly you may get a way with an over size and fitted key
Hope the crank was not bent, looks like it elongated the seal when running eccentrically
As far as the crank goes, from the pics it looks like just a little effort with some emory cloth should polish that up and you'd be fine.... my overwhelming question though is where in the hell did all that oil come from? Did it damage the timing set seal? THAT is what would be my immediate concern......
Originally Posted by Ingenieur
Sucks
Where did the oil come from?
If the pully fits properly you may get a way with an over size and fitted key
Hope the crank was not bent, looks like it elongated the seal when running eccentrically
I'm assuming the oil is from the front seal when the car was running while the pulley was off the crankshaft.
Originally Posted by Ingenieur
What does the key slot on the crank look like?
To shesr that takes some serious force
I posted an additional picture of the crankshaft so you can see the other part of the woodruff key.
I was told that I am not the only one who has experienced this with the Evosport crank pulley. I wanted to contact Evosport but it looks like they are out of business.
Polish the crank And you could try putting a new keyway on the crank with the weistec tool for stage 3. Just drill out the crank with their tool and then drill out a stock pulley to match up and install the key way.
Either that or ask Weistec if you could convert over to a 8 rib pulley system and change all the pulleys on the front of the engine to their 8 rib. This would be more $$$ but a better system for sure. The 8 rib system from their stage 3 has two extra keyways you drikk out on the crank so the broken one wouldn't matter. Make sure all pulleys are torqued to spec and blue loctite on all clean threads.
Polish the crank And you could try putting a new keyway on the crank with the weistec tool for stage 3. Just drill out the crank with their tool and then drill out a stock pulley to match up and install the key way.
Either that or ask Weistec if you could convert over to a 8 rib pulley system and change all the pulleys on the front of the engine to their 8 rib. This would be more $$$ but a better system for sure. The 8 rib system from their stage 3 has two extra keyways you drikk out on the crank so the broken one wouldn't matter. Make sure all pulleys are torqued to spec and blue loctite on all clean threads.
If I went with deciding to change all the pulleys to the 8 rib system, what would I do about the supercharger pulley? Is the stage 3 pulley the same diameter as the stage 2?
So I went to go drive my car yesterday and as I was down the street from my house my power steering went out and the battery light came on. I turned around and headed back to the house and popped the hood to discover that my crankshaft pulley was laying at the bottom of the car covered in oil and the serpentine belt was tangled up. After moving some hoses and finally getting to the crank pulley, I found that the previous owner had failed to mention that he had a Evosport pulley installed on the car. My guess is that the pulley was not torqued down correctly when installed but held just enough when driving with the stock belt. Most likely the extra tension from me installing the supercharger made the pulley finally give way, and snapped the woodruff key along with it.
My question is that will I have to replace the crankshaft with the minor damage the pulley did to the shaft or could I just removed the broke woodruff key and replace a new one with the OEM crankshaft pulley? I'm really hoping that I won't have to have the motor pulled and replace the entire shaft as this is a very expensive repair job to do. Please let me know if you guys can help or give me some advice. It would be greatly appreciated.
Here are some pictures of the aftermath.
Ouch, nasty business, as others have mentioned it would have taken a huge amount of force to shear the key. I am no expert but, the crank nose is blue, looks like a lot of heat build up there unless that is normal on these cars? Could it have been spinning on the shaft before letting go?
The oil spattter is due to the pulley having a rear 'snout' that when installed is through the seal provides a sealing surface between the pulley and the seal not the crankshaft and seal.
The seal replacement shoudl be fairly easy.
When the pulley came off the engine continued to run. Since the seal between the pulley and seal was lost oil came out.
Unless the end of the crankshaft is tapered or the threads are opposite the rotation of the crankshaft the bolt does little to prevent the pulley from spinning on the crankshaft.
My thought is that the woodruff key failed first. This allowed the pulley to spin on the crankshaft. And since the bolt backed out the threads are not in the opposite direction of crankshaft rotation.
When cleaning up the crankshaft be careful not to remove much material. The fit between the pulley and shaft needs to be very close. If when installed (without the bolt) the pulley can be wiggeled around on the cranschaft you will have problems.
The threads are counter clock wise if I remember correctly??
Pnutz, ask weistec, I am not sure. Stage 3 pulleys are most likely smaller. I am sure they could machine you a custom one if you ask and explain your situation.
Isn't it standard practice for pullies,fans and such to thread opposite rotation so they tighten in operation?
It is but I've never had one off of a MB and can't say for sure.
That being said, if it is threaded reverse of rotation I can't see how the bolt backed out unless the bolt was not in contact with the pulley.
Withe the woodruff key being sheared the bolt should have tightened, most likely to the point of snapping off.
OP. Since you did not install the pulley I recommend also checking to make sure use bolt is not bottoming out before contacting the pulley. If it bottoms out before contacting the pulley it will not properly torque.
It is but I've never had one off of a MB and can't say for sure.
That being said, if it is threaded reverse of rotation I can't see how the bolt backed out unless the bolt was not in contact with the pulley.
Withe the woodruff key being sheared the bolt should have tightened, most likely to the point of snapping off.
OP. Since you did not install the pulley I recommend also checking to make sure use bolt is not bottoming out before contacting the pulley. If it bottoms out before contacting the pulley it will not properly torque.
Good point re: bolt not fully seated or too long
Look at the pics
There is a good one of the bolt
The threads look all bunged up
Which doesn't bode well for the female crank portion
It is but I've never had one off of a MB and can't say for sure.
That being said, if it is threaded reverse of rotation I can't see how the bolt backed out unless the bolt was not in contact with the pulley.
Withe the woodruff key being sheared the bolt should have tightened, most likely to the point of snapping off.
OP. Since you did not install the pulley I recommend also checking to make sure use bolt is not bottoming out before contacting the pulley. If it bottoms out before contacting the pulley it will not properly torque.
If I'm not mistaken, the bolt used on the pulley was one that was provided with pulley kit from Evosport. I think the end of the bolt has a an AMG stamp on it but I'm not for sure and can't check ATM since I'm at work. I ordered a new seal, bolt and pulley. How should I go about cleaning up the scratches on the snout?
Some fine emory cloth with a drop of oil
Cut it into long strips same width as hub
Wrap it around and work it around like sawing/polishing, long smooth strokes (that's what she said lol)
Lightly and regularly checking fit/cleaning with rag
You want the burrs off, not perfect, do NOT remove material, just the burrs
When satisfied clean with brake cleaner and a clean rag, especially threads
Do you have any close up photos of the crank bolt? It kinda looks like the threads are damaged, is this the case? I know the bolt has to be replaced regardless, but I'm wondering if the threads on the crank are damaged as well.
Last edited by CafeRacer87; 12-01-2014 at 02:41 PM.
Do yo have any close up photos of the crank bolt? It kinda looks like the threads are damaged, is this the case? I know the bolt has to be replaced regardless, but I'm wondering if the threads on the crank are damaged as well.
OP, Look at the bright side of it. You will likely pick up a little boost and power once you put a normal size pulley back on since you were under driving the supercharger with the evosport pulley. Good luck with the fix.
Do you have any close up photos of the crank bolt? It kinda looks like the threads are damaged, is this the case? I know the bolt has to be replaced regardless, but I'm wondering if the threads on the crank are damaged as well.
The threads look fine after cleaning some gunk and debree off of it. Any ideas on how I can remove the woodruff key without having to removing the timing chain set?
OP, Look at the bright side of it. You will likely pick up a little boost and power once you put a normal size pulley back on since you were under driving the supercharger with the evosport pulley. Good luck with the fix.
That's if I don't die from a heart attack after paying to get this fixed. Lol I was just starting to have fun with the car and this had to happen. 2 weeks after my supercharger install and my car is out of order again.
The threads look fine after cleaning some gunk and debree off of it. Any ideas on how I can remove the woodruff key without having to removing the timing chain set?
Yep
Looks fine
Can you get a better pic of the crank key, perhaps circle it
Make sure you have a strong magnet tool, drop it and you'll be more miserable
Maybe some tape/rags stuffed to prevent it from falling in
Perhaps a pick?
Another set of hands and good lighting would help
OP - was there anti seize like paste on the threads of the bolt. Also, can you post a picture of the head of the bolt?
Regarding removal of the remaining key, good advice above.
Looking at the pictures I can't tell if the balance key is shared with what I believe is the timing gear inside beyond the seal or if the balancer has its own key.
I'd also consider using a punch to lightly tap it out. The groove should extend to the end of the crank but I can't see that in the pictures. If it does use the punch to tap it perpendicular, away from the crank.
11-30-2014, 08:31 PM
After moving some hoses and finally getting to the crank pulley, I found that the previous owner had failed to mention that he had a Evosport pulley installed on the car. My guess is that the pulley was not torqued down correctly when installed but held just enough when driving with the stock belt. Most likely the extra tension from me installing the supercharger made the pulley finally give way, and snapped the woodruff key along with it. 
You will likely pick up a little boost and power once you put a normal size pulley back on since you were under driving the supercharger with the evosport pulley. Good luck with the fix.
