cracked flywheel
Thread Starter
5th Gear
Joined: Jun 2008
Posts: 5
Likes: 0
cracked flywheel
hello !
I'm new to this forum even if it's now 14 years that I own a 1960 corvette here in France.
I'm replacing both transmission and clutch on my car and I experience a few problems:
first is that I found a lot of very small cracks on the flywheel. I replaced a lot of clutches and never saw that on other type of car. I think I need to replace the flywheel but I would like your advise on that.
second problem is the pilot bearing. the service manual recommend to change it in case it has wear but not a lot of details. mine is moving inside the crankshaft and I can pull it a little bit outside the crankshaft but not enough to replace it. Do you recommend to replace it anyway ? the one that was provided with the clutch has the right inside diameter but is too small on outside diameter
I'm also looking for the alignment tool but I can't find it anywhere
thanks for your help !
I'm new to this forum even if it's now 14 years that I own a 1960 corvette here in France.
I'm replacing both transmission and clutch on my car and I experience a few problems:
first is that I found a lot of very small cracks on the flywheel. I replaced a lot of clutches and never saw that on other type of car. I think I need to replace the flywheel but I would like your advise on that.
second problem is the pilot bearing. the service manual recommend to change it in case it has wear but not a lot of details. mine is moving inside the crankshaft and I can pull it a little bit outside the crankshaft but not enough to replace it. Do you recommend to replace it anyway ? the one that was provided with the clutch has the right inside diameter but is too small on outside diameter
I'm also looking for the alignment tool but I can't find it anywhere
thanks for your help !
Race Director
Joined: Oct 2005
Posts: 12,470
Likes: 1,548
From: Camp Verde AZ
C1 of Year Finalist (performance mods) 2019
2017 C1 of Year Finalist
small cracks on flywheel surface is from over heating the clutch, reving and dumping clutch, slipping clutch, etc. Usually not a problem.
Replace the pilot bearing. I would try a slide hammer witha hook attachement to try and get the old one out, if it is loose, it should pop out.
When you say too small, how too small? A few thousandths, or whole lots?
What is the diameter of the repalcement bearing, exactly?
You can get GM specific clutch alignment tools or universal tool sets with interchangable pilot bushing size tips, etc. I would do an internet search if you can't get them locally.
Doug
Replace the pilot bearing. I would try a slide hammer witha hook attachement to try and get the old one out, if it is loose, it should pop out.
When you say too small, how too small? A few thousandths, or whole lots?
What is the diameter of the repalcement bearing, exactly?
You can get GM specific clutch alignment tools or universal tool sets with interchangable pilot bushing size tips, etc. I would do an internet search if you can't get them locally.
Doug
Race Director
Joined: Oct 2005
Posts: 12,470
Likes: 1,548
From: Camp Verde AZ
C1 of Year Finalist (performance mods) 2019
2017 C1 of Year Finalist
A standard pilot bearing is about 1.097" outside diameter, according to the one I measured on my bench. A little less than 28 mm to you.
If memory serves me correctly, there was one crankshaft in one year passenger car that took a much larger diameter pilot bearing for some reason. can't tell you any more than that.
Doug
If memory serves me correctly, there was one crankshaft in one year passenger car that took a much larger diameter pilot bearing for some reason. can't tell you any more than that.
Doug
Advanced
Joined: Nov 2006
Posts: 82
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For what it is worth, it is my understanding that the only Chevy crankshaft that was transmission specific was in the engines coupled to the turboglides. If you wanted to use the engines assembled with that crank on a manual transmission, you had to get an aftermarket, oversized pilot bushing to fit the crank. Or have one made. The turboglides were available from '57 thru at least '61. I have no idea how large the bushing had to be, but others have said it was "very large", much bigger that the 1.097" described above.
Le Mans Master
Joined: Nov 2006
Posts: 7,215
Likes: 1
From: Orlando FL
small cracks on flywheel surface is from over heating the clutch, reving and dumping clutch, slipping clutch, etc. Usually not a problem.
Replace the pilot bearing. I would try a slide hammer witha hook attachement to try and get the old one out, if it is loose, it should pop out.
When you say too small, how too small? A few thousandths, or whole lots?
What is the diameter of the repalcement bearing, exactly?
You can get GM specific clutch alignment tools or universal tool sets with interchangable pilot bushing size tips, etc. I would do an internet search if you can't get them locally.
Doug
Replace the pilot bearing. I would try a slide hammer witha hook attachement to try and get the old one out, if it is loose, it should pop out.
When you say too small, how too small? A few thousandths, or whole lots?
What is the diameter of the repalcement bearing, exactly?
You can get GM specific clutch alignment tools or universal tool sets with interchangable pilot bushing size tips, etc. I would do an internet search if you can't get them locally.
Doug
Safety Car
Joined: Feb 2006
Posts: 4,142
Likes: 704
For what it is worth, it is my understanding that the only Chevy crankshaft that was transmission specific was in the engines coupled to the turboglides. If you wanted to use the engines assembled with that crank on a manual transmission, you had to get an aftermarket, oversized pilot bushing to fit the crank. Or have one made. The turboglides were available from '57 thru at least '61. I have no idea how large the bushing had to be, but others have said it was "very large", much bigger that the 1.097" described above.
You are correct. Lots of info on this in the archives.
Thread Starter
5th Gear
Joined: Jun 2008
Posts: 5
Likes: 0
it might be my problem.
I purchased this car in california 14 years ago and I can't really know what is stock in this car !
I had a muncie M20 transmission installed and I think this was not available at the factory for a 1960 model.
Maybe my engine has been replaced also ? because I don't see any turbo here
I purchased this car in california 14 years ago and I can't really know what is stock in this car !
I had a muncie M20 transmission installed and I think this was not available at the factory for a 1960 model.
Maybe my engine has been replaced also ? because I don't see any turbo here
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Instructor
Joined: Nov 2005
Posts: 160
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From: Hamden CT
Removing pilot bushing
hello !
I'm new to this forum even if it's now 14 years that I own a 1960 corvette here in France.
I'm replacing both transmission and clutch on my car and I experience a few problems:
first is that I found a lot of very small cracks on the flywheel. I replaced a lot of clutches and never saw that on other type of car. I think I need to replace the flywheel but I would like your advise on that.
second problem is the pilot bearing. the service manual recommend to change it in case it has wear but not a lot of details. mine is moving inside the crankshaft and I can pull it a little bit outside the crankshaft but not enough to replace it. Do you recommend to replace it anyway ? the one that was provided with the clutch has the right inside diameter but is too small on outside diameter
I'm also looking for the alignment tool but I can't find it anywhere
thanks for your help !
I'm new to this forum even if it's now 14 years that I own a 1960 corvette here in France.
I'm replacing both transmission and clutch on my car and I experience a few problems:
first is that I found a lot of very small cracks on the flywheel. I replaced a lot of clutches and never saw that on other type of car. I think I need to replace the flywheel but I would like your advise on that.
second problem is the pilot bearing. the service manual recommend to change it in case it has wear but not a lot of details. mine is moving inside the crankshaft and I can pull it a little bit outside the crankshaft but not enough to replace it. Do you recommend to replace it anyway ? the one that was provided with the clutch has the right inside diameter but is too small on outside diameter
I'm also looking for the alignment tool but I can't find it anywhere
thanks for your help !
Once you have a suitable length of rod as described, all you need to know is that heavy wheel bearing grease is just as incompressible as water, and therefore can't be made to fit into a smaller space than it already occupies. So, just pack the cavity behind the pilot bushing with wheel bearing grease until it's full, insert the rod into the bushing and hold it in position with a shop towel covering the end near the pilot bushing end, and whack the rod into the bushing. The grease being displaced will push on the back side of the bushing with about the same force that hit the rod, since that mechanical action will create an equal and opposite reaction. You might need to pack some additional grease into the cavity as the bushing moves out.
Team Owner
Joined: Oct 2000
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From: Washington Michigan
