why does my flywheel not fit onto the crank?!
06-19-2009, 12:22 AM
#1
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why does my flywheel not fit onto the crank?! I bought a monster level 4 clutch kit and im trying to install the flywheel. the flywheel does not slide onto the crank. the hole in the middle of the flywheel is too small. I compared it to the stock one and the hole is much bigger. this is going on a 408 with a scat crank. Why the **** does this not fit?!
06-19-2009, 12:28 AM
#2
Thats a wierd one. Pics? I have mine on the way I hope I don't have this problem. Was the "stock" one attached to that motor already? Basically what I'm getting at is if the back of the crank was bigger and a different flywheel was used to accomodate this.
06-19-2009, 12:32 AM
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the stock one was off of a bone stock ls1. this is a brand new motor and the hole in the flywheel is simply not large enough to slide over the crank flange.
06-19-2009, 01:44 PM
#5
Is the crank snout on your 408 larger? In other words, will your ls1 flywheel fit? If not, then maybe it's a crank issue. Get a good micrometer and measure the diameter, and have the flywheel opened to match. If the ls1 flywheel fits, then it's an issue with the Monster flywheel.
06-19-2009, 02:45 PM
#6
Though it is possible that this part was miss-machined...this isn't very likely due to the use of mechanized and highly accurate CNC/Mills that are used in the manufacturing process (at least that's the case for our flywheel). But, I can't speak for monster's manufacturing processes so maybe one of them can chime in with more specifics.
There are two possible causes for this issue. It is most likely a combination of the two that is responsible for your issue. Parts are typically built within a specification window. This means that there can be a set amount of variance in the diameter of the flywheels center-bore that would be considered normal. Simultaneously, there can also be a set acceptable variance on the ID of the crank itself. If for instance the crank end was a little on the high side of tolerance and the flywheel was a little on the low side of tolerance this could cause an interference between the parts.
As you may know, there are a number of automotive parts that are intended to have an interference fitment. In the case of a flywheel/crank coupling this is not typically normal, but this doesn't inherently mean that the part is wrong. You must also remember that the two materials used for the crank and the flywheel have a different composition. This means that at any given temperature there can be a slight reduction or expansion of the ID/OD (crank and flywheel bore). That being said, you can likely heat the flywheel a bit which would open up the center bore, allowing it to fit the crank. Heating the flywheel can be done in an oven or with a torch (it shouldn't take an exorbitant amount of temperature to do this).
Of course, you can also measure the ID of the flywheel center bore (that would slip over the crank) and the OD of the crank end (that the flywheel fits over) and deduct the difference to better assess the amount of interference between the parts. Let us know what number you come up with and I will be happy to provide more info. Thanks and good luck!
There are two possible causes for this issue. It is most likely a combination of the two that is responsible for your issue. Parts are typically built within a specification window. This means that there can be a set amount of variance in the diameter of the flywheels center-bore that would be considered normal. Simultaneously, there can also be a set acceptable variance on the ID of the crank itself. If for instance the crank end was a little on the high side of tolerance and the flywheel was a little on the low side of tolerance this could cause an interference between the parts.
As you may know, there are a number of automotive parts that are intended to have an interference fitment. In the case of a flywheel/crank coupling this is not typically normal, but this doesn't inherently mean that the part is wrong. You must also remember that the two materials used for the crank and the flywheel have a different composition. This means that at any given temperature there can be a slight reduction or expansion of the ID/OD (crank and flywheel bore). That being said, you can likely heat the flywheel a bit which would open up the center bore, allowing it to fit the crank. Heating the flywheel can be done in an oven or with a torch (it shouldn't take an exorbitant amount of temperature to do this).
Of course, you can also measure the ID of the flywheel center bore (that would slip over the crank) and the OD of the crank end (that the flywheel fits over) and deduct the difference to better assess the amount of interference between the parts. Let us know what number you come up with and I will be happy to provide more info. Thanks and good luck!
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06-23-2009, 12:41 PM
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I have tried using a torch to heat it up while screwing in the bolts to force it to slide over the crank. this seemed to work but I think its destroying the threads in my crank and my bolts. One of the bolts was not going as well as the other so i took it out and some of the threads were completely gone. now when i try to screw bolts into that hole it just does the same thing to that bolt. i cant even unscrew some of these bolts either.
06-23-2009, 01:03 PM
#10
You shouldn't have to use bolts to pull the flywheel down...make note that I never mentioned doing this in my post and I would not suggest doing this at all. By using bolts to pull the flywheel on you risk damaging the crank and that isn't what you want at all, though it sounds like this may be what has occured.
06-23-2009, 02:18 PM
#11
I reread your first post, and if your stock flywheel had an opening much larger than this flywheel, then there is an issue with the flywheel, and I don't care if the Monster rep doesn't think so.
I'd be looking a new/different flywheel if I were you.
I'd be looking a new/different flywheel if I were you.
06-23-2009, 06:54 PM
#12
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measurements dont lie. you need to measure the crank and the flywheel and figure out what is going on there. if you couldnt get it on with heat and trying to draw it on with the bolt (bad idea) there is something very wrong there. let us know the measurements and maybe someone can compare them to stock measurements and see witch is wrong.
06-23-2009, 10:14 PM
#13
I would rather buy a new flywheel than to even think about stripping my crank threads. Like styoung said measurements don't lie. Thats the first think you should of did when you seen something wasn't right.
06-24-2009, 10:03 AM
#14
Agreed...it is impossible for measurement to provide misinformation, as long as they are taken correctly. That being said, let me know what your crank diameter is and I will compare this to our known value for the OE parts used to mock up our flywheels for programming and production. This way you can know for sure whether it is a crank variance or a part variance. Thanks,
06-24-2009, 09:25 PM
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i had a under machined hole on my stock replacement flywheel i used a dremmel to take the little bit of extra material out so it would fit on. i did CNC machining for about 6 years maybe they didn't make a correct offset or a insert broke or chipped a corner...
