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I replaced the ring gear on my Hays billet steel 168 tooth flywheel and dropped it off to be resurfaced. The shop called and said there was a bad warp in it and they couldn’t resurface it. What’s the deal, I thought that was partially the reason to get it resurfaced? Is it scrap?
That is strange - the Hays 30 lb flywheel I bought back in the 90s had a lot of runout right out of the box but I got it surfaced by a good shop and it was fine. If they can't resurface yours it must really be warped or they are just lazy. I guess it's possible that could contribute to your second gear engagement issue - if the clutch and flywheel are wobbling around the disc is possibly getting batted around which wiggles the input shaft as you the syncro collar is trying to engage third. But I would think you would be getting chatter or shuddering as you release the clutch if it's out a lot. I don't know - would they tell you how much it was out?
Last edited by DansYellow66; Oct 23, 2019 at 08:08 AM.
I would bring it to another machine shop, I have seen some pretty beat up flywheels resurfaced with no issue.
There should be plenty of metal, and it is a steel billet, so failure issues with less metal should be nil.
HOWEVER, if too much cut is taken, you may have clutch adjustment issues after installation............as clutch is moved closer to the engine. OEM flywheel (GM) is 0.970 inches thick as a reference point. This is crank surface to disc surface.
Larry
Last edited by Powershift; Oct 22, 2019 at 09:30 AM.
If the flywheel is located off the crank flange surface, I don't see any reason that flywheel couldn't be trued up unless it was totally worthless before you gave it to them.
From: Middle TN by way of KY, OH, VA, IL, CA, FL, NY, SC, HI
If the flywheel bolting flange is so badly out of plane to the friction surface that cutting the friction surface true results in the flywheel being under minimum thickness - or - the friction surface runout is so bad that cutting it results in it being under minimum thickness, then the machine shop comment makes sense.
However, that requires more runout than rational for either a new flywheel or one that was successfully used without huge problems.
You might have the machine shop show you the runout just to see, but I agree with above posters that say to take it to another machine shop and see if they say the same thing. If so, return it if new, toss it and buy new if it's used.
The flywheel that is now in the car as been there for about two years is cast iron, and I’ve read that that’s not recommended for a BB. I had this billet one and would like to get it in like new condition so the tranny shop can install it when they pull the tranny for the 4th time. I installed a new ring gear on it yesterday.
Today I took it to a “real” machine shop and will hear back tomorrow on their evaluation.
What are the symptoms of a bad flywheel with high runout? I would have thought shuddering or chatter but the new Hays flywheel I ran for a few months that was anything but flat didn't seem to cause a chatter issue with the clutch and was still smooth. It seems like I started down the road that lead me to checking the flywheel, finding it was about .016" or .018" out (from memory) and having it surfaced when the transmission started popping out of gear (don't remember which one) and while trying to fix a vibration (probably the worn tail bushing and worn trans yoke). Does it cause any specific issues like popping out of 3rd or 4th gear - anyone know for sure?
On the same subject, does anybody know what the min. thickness of a flywheel is?
Depends on the flywheel. But see Post #4 for OEM thickness: OEM original 0.970 inch.
Larry
EDIT: Based on many discussions here and elsewhere, 0.960 inch thickness is a good/agreed minimum for OEM flywheel for proper clutch adjustments and general function.
Last edited by Powershift; Oct 23, 2019 at 12:40 PM.
Just picked up my flywheel, they did an excellent job and it’s a full size machine shop. He said it was out about .006” TIR, cleaned up nice.That first place was a joke! Overall thickness is .915-.917”
Last edited by 59BlueSilver; Oct 23, 2019 at 01:49 PM.
Amen to that! And here’s the bellhousing to go with it. Match all this up with my existing 12” clutch and reworked tranny (4th time!) and hopefully everything will fit and work out. I take it in Monday.
At the very least, you need to either check the bell housing run out or have some kind of assurance someone has not installed offset dowels to align the former bell housing.
Okay, according to Buns diagram, my bellhousing is 4.75” and flywheel measurement is .8” so I need to reduce ball height to 4.59".
Is this the adjustable ball I need?
At the very least, you need to either check the bell housing run out or have some kind of assurance someone has not installed offset dowels to align the former bell housing.
Yes, I know, dialing in is not an option but I’m hoping I can at least identify whether stock dowels were used.
Yes, I know, dialing in is not an option but I’m hoping I can at least identify whether stock dowels were used.
Why not?? You can likely borrow the tools and indicators to do this job. If you don't know how....ask. I have a Technical Paper on this that was presented to NCRS guys about 7-8 years ago. Very easy to follow.
But if not, the Browell Alignment Tool is out there for use by C2 CF members. Check for it or start a new post for where it is now. About 1-2 months ago, its whereabouts were known.
Why not?? You can likely borrow the tools and indicators to do this job. If you don't know how....ask. I have a Technical Paper on this that was presented to NCRS guys about 7-8 years ago. Very easy to follow.
But if not, the Browell Alignment Tool is out there for use by C2 CF members. Check for it or start a new post for where it is now. About 1-2 months ago, its whereabouts were known.
Larry
I could do it myself after getting the proper tools and instructions, but, as I said before, it’s not in my shop and when I asked him about this procedure I got the deer in the headlights look, and I’m not about to finance his education. This shop just pulls transmissions and sends them out for rebuild. He does volume business and can’t have a car taking up space on his lift for very long. Now, can we get past this dial in procedure? I know it’s the proper way to do it but my thought was to get rid of the Lakewood and backing plate which probably need dialing in and go with my reworked flywheel, new 12” clutch, and stock truck bellhousing with stock dowels. GM didn’t dial this stuff in.
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Flywheel
There should be plenty of metal, and it is a steel billet, so failure issues with less metal should be nil.
