Flywheel-pressure plate alignment

[Steve L.]

My original parts do not have an "X" stamped in these parts. But it looks like they have an "F" stamped in as per attached photos. This is for a 73 SB L48. Does this make any sense?

[Joe L.]

Re: Flywheel-pressure plate alignment

My original parts do not have an "X" stamped in these parts. But it looks like they have an "F" stamped in as per attached photos. This is for a 73 SB L48. Does this make any sense?

Steve------


I suppose it's possible an "F" was used instead of an "X". However, it's really pretty irrelevant unless you are re-installing the original, unsurfaced flywheel and original pressure plate assembly. However, whether you are or not, I would still recommend having the flywheel and pressure plate assembly re-balanced by a competent balance shop before re-installation. In that case, the original marks mean nothing. The balance shop will make new alignment marks.

[Steve L.]

Re: Flywheel-pressure plate alignment

Thanks Joe,
Why is it that some Corvette vendors sell the clutch plate and pressure plate as a combination only when you should balance these anyways?

When taking these in for balancing, do you assemble the three items, i.e. pressure plate, clutch plate and flywheel togther yourself or bring all three separately to the balance people?

[Timothy B.]

Re: Flywheel-pressure plate alignment

Steve,

When I did my 63 300hp engine the flywheel is zero balanced then the pressure plate is balanced with the flywheel and marked with ink so the clocking is clear when installing on the engine. Factory markings use a X on the pressure plate and flywheel but it's the same principle.

I don't believe the disc is balanced as this part spins freely when the clutch is disengaged. It's probably balanced when it's assembled but I don't believe my disc was touched when the engine was balanced.

[Clem Z.]

Re: Flywheel-pressure plate alignment

always balance the 2 part separately. if you balance them together every time you change the pressure plate you have to do it all over again. most good pressure plates come "0" balance from the factory.

[Tom P.]

Re: Flywheel-pressure plate alignment

always balance the 2 part separately. if you balance them together every time you change the pressure plate you have to do it all over again. most good pressure plates come "0" balance from the factory.

I agree totally, completely, 100%!
For ALL internally (neutral) balanced engines, the flywheel and the clutch pressure plate should be independantly balanced to neutral (zero) balance!!! Also, ANY pressure plate, REGARDLESS of whether it is for an internal balance or external (such as a 454 or SB400) balance engine, should be neutral balanced. Thus, when either or both the clutch and/or flywheel are removed/replaced, they will NOT need to be repositioned in the same position as they were when removed.
With an EXternal balanced engine, there is no choice on the positioning of the flywheel because the added weight on one side of a 454 or SB400 flywheel (or flexplate) MUST be positioned the same as it was when removed for proper balance of the whole engine.
Engine balancing SHOULD NEVER be accomplished on the pressure plate. It should always be neutral. Also, the clutch disc should always be neutral because EVERY TIME the clutch is released, the disc changes it position in relationship to the flywheel and pressure plate.

[Joe L.]

Re: Flywheel-pressure plate alignment

Thanks Joe,
Why is it that some Corvette vendors sell the clutch plate and pressure plate as a combination only when you should balance these anyways?

When taking these in for balancing, do you assemble the three items, i.e. pressure plate, clutch plate and flywheel togther yourself or bring all three separately to the balance people?

Steve------


I've had brand new GM pressure plate assemblies that were WAY off in balance out-of-the-box.

You should bring the components to the balance shop as separate pieces. They will take it from there. They usually balance the flywheel and pressure plate separately to neutral balance. They do not usually do anything with the friction disc but I still take it in.

After the flywheel and pressure plate are independently neutral balanced, they usually bolt it all together and check the balance as a complete assembly. If necessary, they may make very small balance adjustments. They usually always mark the flywheel and pressure plate even though it might not really be necessary to maintain the relationship between the flywheel and pressure plate.

[Steve L.]

Re: Flywheel-pressure plate alignment

Thanks Joe,
My originals are in good shape. I'll get them balanced separately and get a new clutch plate.