Flywheel bolts not fitting thru flywheel/pics
05-05-2009, 10:04 PM
#1
Instructor
Thread Starter
Flywheel bolts not fitting thru flywheel/pics
I acquired a used, but refinished flywheel for my S2. Lighter than my original, but no official weighing to confirm value.
First thing I noticed was that the bolt holes where recessed. Assumed that the pressure bolts fit in. Well upon install the holes are just a fraction too small for the bolts.
Other than finding a slightly smaller headed bolt, which is probably not going to happen, I will need to have the holes enlarged just a fraction.
Thoughts on this.
First thing I noticed was that the bolt holes where recessed. Assumed that the pressure bolts fit in. Well upon install the holes are just a fraction too small for the bolts.
Other than finding a slightly smaller headed bolt, which is probably not going to happen, I will need to have the holes enlarged just a fraction.
Thoughts on this.
05-05-2009, 10:22 PM
#3
It may be easier to to take the bolt head diameter down slightly. Have you mic'd to see how much difference? Are you certain the bolt pattern lines up with the crankshaft?
05-05-2009, 10:51 PM
#4
Rennlist Member
Enlarging the shoulder chamfer should not be a problem for a machine shop. The problem doesn't sound right though. If it's an S2 flywheel is should fit. Double check the bolt pattern and the diameter and width of the flywheel.
05-05-2009, 10:58 PM
#5
Rennlist Member
This looks suspiciously like a solution to the "cheaper clutch disc" thread -- instead of grinding down the bolt heads (lengthwise) to clear clutch disc springs, recess the bolts into the flywheel? You'd think they'd have made the recesses to fit stock bolts, tho. I have to admit, it looks like a viable solution...
05-05-2009, 11:28 PM
#6
Instructor
Thread Starter
This looks suspiciously like a solution to the "cheaper clutch disc" thread -- instead of grinding down the bolt heads (lengthwise) to clear clutch disc springs, recess the bolts into the flywheel? You'd think they'd have made the recesses to fit stock bolts, tho. I have to admit, it looks like a viable solution...
That's how I read it. Not a bad idea, but what's with the bolt heads being just a shade too large. What bolt did they use?. I don't think the stock bolts would have held. Just not enough material.
Like Forest Gump says; "Life is like a box of chocolates: you never know what you're gonna get"
05-05-2009, 11:32 PM
#7
Instructor
Thread Starter
Thanks
Trending Topics
05-05-2009, 11:36 PM
#8
Instructor
Thread Starter
The only thing I can think of is that the prior user had in his possession slightly small bolts.
So it looks like it's off to the machine shop. Groan
05-06-2009, 12:01 AM
#9
Rennlist Member
I'm curious, how deep are the recesses? How thick is the remaining flywheel at the recesses? As I mentioned in the "cheap disc" thread, flywheel bolts are under a great deal of stress and flywheels themselves are not something to mess with -- ever seen the aftermath of a clutch/flywheel explosion?! It will nearly cut the car in half. Just wondering if the remaining thickness looks stout enough to you? Were you going to have the recesses enlarged or the bolt heads reduced?
05-06-2009, 01:14 AM
#10
Three Wheelin'
I'm sure you don't want to hear this, but if I had bought that flywheel I would be asking for my money back. If I was stuck with it, I'd chalk it up as a loss and throw it away, maybe make a clock or some other type of garage decoration out of it, anything but bolt it into my car.
Here's why:
1. The area under the bolt heads is not as thick as designed, this will not do as good as a job at distributing the clamping force of the bolts. Affect, the shear capacity of the joint is reduced.
2. Recessing the bolt head reduces the material cross section between the bolts. This will reduce the flywheels RPM limit before it comes apart (usually taking out anything around it, i.e. bell housing, car body, occupants legs, etc...)
I bet regular allen bolt heads will fit right into those holes........
some people shouldn’t be allowed near milling machines.
Here's why:
1. The area under the bolt heads is not as thick as designed, this will not do as good as a job at distributing the clamping force of the bolts. Affect, the shear capacity of the joint is reduced.
2. Recessing the bolt head reduces the material cross section between the bolts. This will reduce the flywheels RPM limit before it comes apart (usually taking out anything around it, i.e. bell housing, car body, occupants legs, etc...)
I bet regular allen bolt heads will fit right into those holes........
some people shouldn’t be allowed near milling machines.
05-06-2009, 02:28 AM
#11
Instructor
Thread Starter
I'm curious, how deep are the recesses? How thick is the remaining flywheel at the recesses? As I mentioned in the "cheap disc" thread, flywheel bolts are under a great deal of stress and flywheels themselves are not something to mess with -- ever seen the aftermath of a clutch/flywheel explosion?! It will nearly cut the car in half. Just wondering if the remaining thickness looks stout enough to you? Were you going to have the recesses enlarged or the bolt heads reduced?
Cann't find my mil measuring thing but essentially the recess is about 35% of the total thickness.
"cheap disc" thread
I'll look for it.
Pic below
Were you going to have the recesses enlarged or the bolt heads reduced
Upon closer inspection I do not think there is enough material to remove before breaching the side of inside ring.
Can't imagine that machining the heads of the 9 bolts is going to be easy.
Here is a close up. The bolt head is kind of sitting in the hole, but it's a long way from going thru.
Last edited by ArcticSteve; 05-06-2009 at 02:30 AM. Reason: picture
05-06-2009, 02:53 AM
#14
Instructor
Thread Starter
I'm sure you don't want to hear this, but if I had bought that flywheel I would be asking for my money back. If I was stuck with it, I'd chalk it up as a loss and throw it away, maybe make a clock or some other type of garage decoration out of it, anything but bolt it into my car.
Here's why:
1. The area under the bolt heads is not as thick as designed, this will not do as good as a job at distributing the clamping force of the bolts. Affect, the shear capacity of the joint is reduced.
2. Recessing the bolt head reduces the material cross section between the bolts. This will reduce the flywheels RPM limit before it comes apart (usually taking out anything around it, i.e. bell housing, car body, occupants legs, etc...)
I bet regular allen bolt heads will fit right into those holes........ some people shouldn’t be allowed near milling machines.
Here's why:
1. The area under the bolt heads is not as thick as designed, this will not do as good as a job at distributing the clamping force of the bolts. Affect, the shear capacity of the joint is reduced.
2. Recessing the bolt head reduces the material cross section between the bolts. This will reduce the flywheels RPM limit before it comes apart (usually taking out anything around it, i.e. bell housing, car body, occupants legs, etc...)
I bet regular allen bolt heads will fit right into those holes........
some people shouldn’t be allowed near milling machines.Quite used to it.
Thanks for the reality slap. I will endeavor to have the original flywheel resurfaced locally. The reason I got the flywheel in the first place, from a known US commercial vendor, and had my sister cart it up here from KY to the wilderness, is that I didn't have faith in the local shops.
Return shipping from Ontario would cost more than the initial cost. The agony of it all.
Appreciate all the responses. All where sending me the same message: DO NOT PROCEED.
05-06-2009, 08:40 AM
#15
Drifting
Join Date: May 2008
Location: Virginia Beach, VA
Posts: 2,080
Likes: 0
Received 15 Likes
on
11 Posts
I'm sure you don't want to hear this, but if I had bought that flywheel I would be asking for my money back. If I was stuck with it, I'd chalk it up as a loss and throw it away, maybe make a clock or some other type of garage decoration out of it, anything but bolt it into my car.
Here's why:
1. The area under the bolt heads is not as thick as designed, this will not do as good as a job at distributing the clamping force of the bolts. Affect, the shear capacity of the joint is reduced.
2. Recessing the bolt head reduces the material cross section between the bolts. This will reduce the flywheels RPM limit before it comes apart (usually taking out anything around it, i.e. bell housing, car body, occupants legs, etc...)
I bet regular allen bolt heads will fit right into those holes........ some people shouldn’t be allowed near milling machines.
Here's why:
1. The area under the bolt heads is not as thick as designed, this will not do as good as a job at distributing the clamping force of the bolts. Affect, the shear capacity of the joint is reduced.
2. Recessing the bolt head reduces the material cross section between the bolts. This will reduce the flywheels RPM limit before it comes apart (usually taking out anything around it, i.e. bell housing, car body, occupants legs, etc...)
I bet regular allen bolt heads will fit right into those holes........
some people shouldn’t be allowed near milling machines.