Flywheel Machining

[James W.]

What would be a recommended or maximum amount of material that can be machined off of a flywheel. The flywheel in question is from a 1967 L79 equipped Corvette. Would 0.0060" be too much in order to true it up and remove any hard spots. This would done on an engine lathe by and journeyman machinist.

Thoughts and opinions would be greatly appreciated.


Thanks,

James

[Joe L.]

Re: Flywheel Machining

What would be a recommended or maximum amount of material that can be machined off of a flywheel. The flywheel in question is from a 1967 L79 equipped Corvette. Would 0.0060" be too much in order to true it up and remove any hard spots. This would done on an engine lathe by and journeyman machinist.

Thoughts and opinions would be greatly appreciated.


Thanks,

James

James-------


Personally, I do not recommend ANY machining of flywheels. However, in your case, if all you need to remove is actually 0.006", I think that would be OK.

A NEW flywheel for your application is available from LUK under LFW131 and you should be able to buy one for less than 75 bucks.

[Barry H.]

Re: Flywheel Machining

James, Most good automotive machine shops can resurface your flywheel using a "Blanchard" grinder, they usually remove the minimum to just get rid of hard spots & grooves. They will be able to also balance it including the clutch if needed.
Barry

[Carl N.]

Re: Flywheel Machining

Agree with Barry, take flywheel and clutch assembly to reptubable machine shop. They will let you know if it can be resurfaced or if replacement is required.

[Bob R.]

Re: Flywheel Machining

If you machine the original fly wheel you may have an issue with the clutch adjustment. I didn't think it would cause an issue but it did and I ended up installing shims to get the adjustment correct.

[Joe L.]

Re: Flywheel Machining

If you machine the original fly wheel you may have an issue with the clutch adjustment. I didn't think it would cause an issue but it did and I ended up installing shims to get the adjustment correct.

Bob------


Absolutely correct. In fact, that's one of the reasons that I do not recommend flywheel machining. The clutch release mechanism on 1963-81 Corvettes is "delicately balanced". At its best (i.e. with everything in new condition), it's difficult to obtain the specified free play and still obtain complete clutch release with the pedal at the limit of its travel. GM made many slight revisions of the system over the 63-81 period, apparently in an attempt to solve this problem. They never did, though. If any material is removed from the flywheel or the pressure plate, the problem is exacerbated. If many aftermarket clutches are installed, especially "high performance" or "trick" types, the problem is often exacerbated. Personally, I would be very uncomfortable with any shimming to address this problem. My solution is a new flywheel.

Machining of a flywheel also reduces its strength and reduces its ability to absorb friction-generated heat.

[John L.]

Re: Flywheel Machining

Bob
I agree with Joe L, - when I refurbished my '65, I resurfaced the original flywheel and reused the nearly new clutch plate, cover and TO bearing. The adjustment nuts only moved down rod a minor (1/4"?) amount but it's never felt as good engaging/disengaging as it did before.