Flywheel Restoration

[Gary AAR]

Looking to restore the engine flywheel/ring gear assembly from my 70 340 Cuda.  I'll get the flywheel resurfaced, but what can be done to cleanup the rust on the ring gear?  Can you media blast (glass bead) the ring gear teeth without adversely affecting the gear tooth contact area?  If so, should I media blast the entire assembly (including the clutch surface area), and then have the clutch contact area resurfaced? 

Anybody have a different technique that they've found to work?
Thanks for the help.

[Rich G.]

You can use something like Evapo Rust and let it soak in that .

[JS29]

Can a new ring gear still be perchest?   

[Burdar]

My first thought was EvapoRust but...

I soaked some window mechanisms with springs in EvapoRust to clean them up.  The springs were rusty but no damage otherwise.  When I removed them from the EvapoRust, one of the springs was cracked.  When I asked about this on another site, the consensus was that the EvapoRust caused the spring to crack.  Others have seen it happen as well.

I know flywheels can get heat cracks in the friction surface.  I'm not sure if I'd want to experiment with dipping a flywheel.  I know the metal properties are different between a flywheel and a spring but...  I'd hate for a flywheel to become brittle and come apart.  It might not be an issue but I'd like to hear from others if they've done it or not.

[RUNCHARGER]

I would blast them before resurfacing. I usually buy new flywheels.

[anlauto]

Yup, that's all I've done in the past, is just media blast them, then re-surfaced. The last couple of cars I've done just got new ones as well.

[RSI700VIPER]

I would blast them before resurfacing. I usually buy new flywheels.

I brought my six pack flywheel to my engine guy so he could properly balance the crank.  He said I was crazy to put a 50 year old part of such importance back into my numbers matching motor.  Flywheels are heat treated and shatter like glass when they fail, with metal fragments spraying everywhere.  Then I recalled a time a number of years back when my buddy's flywheel exploded on his AMX.  He is lucky to still have his nads.     

[Rich G.]

How would Evaporust break something that wasn't already bad? That's scary to know if it really can!

[Burdar]

How would Evaporust break something that wasn't already bad? That's scary to know if it really can!

Removing rust with an acid or by reverse electrolysis can cause hydrogen embrittlement.  I didn't think EvapoRust was supposed to cause that but I guess it can with spring steel.  My window mechanism springs were under tension while being soaked.(still installed on the mechanisms)