93M6Formula

I'm pulling my new clutch and new flywheel back off to get balanced because of a slight vibration it had.
Question is, do I just have the flywheel and pressure plate bolted together and take it in? Or do I include the disc also?

Also, I can't remember how the LT1 is balanced? What do I tell the shop to do when I take it there?

Birdie2000

iTrader: (15)

A stock LT1 shortblock is externally balanced in the rear.

When I had my flywheel/clutch assembly balanced, they wanted the disc as well as the pressure plate bolts you'll be using for final assembly. My new pressure plate needed a decent amount of balancing.

You mention new flywheel, do you have your old one that had the proper balance for them to match balance it to?

Jason94z

iTrader: (3)

Before you rush off to the machine shop...

Was your old flywheel stock? If so, it's external balance. You have to look at the flywheel for a balance pad that is cast into it. Here you can see my pad has drill marks in it


Is your new flywheel external balance? It will have a balance pad weight on it somewhere if it is. If its not you need an external balance one if the old one you took off was external.

If both new and old flywheels are external balance:
1) did you install the new one lining up the extra hole that's both on the crank and flywheel?
2) if you did, did you also line up the pressure plate correctly to the flywheel? There will be a mark on both the pressure plate and flywheel to properly index them to each other.

That might solve your problem. Let me know what you find in the steps above, and we can take it from there. I just went through this. Good luck!

BALLSS

as noted if you have a stock motor or one that was rebuilt but maintained "external" balance than any stock replacement FW will work as long as you line up the dowel hole on it to the crank. Most aftermarket/replacement clutch kits do not have a paint dab on them to line up with the FW if it had one. If Pp does have a paint dab you line up the paint dab on PP as close to the dowel hole on the crank/FW

for rebuilt motors that are now "internal" balance you need to have a stock FW "neutral" aka "zero" balanced which involves grinding off the cast in weight and drilling out material elsewhere if needed, or buy a aftermarket neutral balance FW. The right way to do it after grinding off counter weight is to add pins in the outer edge holes. A machine shop typically charges $40 for this.

THEN you have the PP balanced to the now balanced FW and the shop will spray paint on a alignment mark so you know how to put it back togeather.

I have a 383 internal balance motor and have had this done a few times. NEVER did they want the disc. If the shop insists it to will or should be marked so you know how to line it up on assembly

the shop first should balance the FW then bolt the PP to it and balance that to the FW

93M6Formula

Thanks for the reply guys!
I did replace the flywheel and I was an idiot and threw away the old one, but I know it was the original flywheel. But it's a stock motor so the new flywheel should just be externally balanced then?

I have a competition stage 2.5 clutch, I didn't see any markings that I know of. I will have my local machine shop take care of it and hopefully the vibration will go away!

SS RRR

iTrader: (2)

You should be fine.

Jason94z

iTrader: (3)

If it was a stock engine and stock flywheel you dont need the old one that you took off and threw out, so don't have to worry about that. All that matters with a stock engine is that your new flywheel be external balance and it will work just fine.

If it has the balance pad on it somewhere you are good to go and the shop can help put the pressure plate on right. If your new flywheel does not have a external balance weight/pad on it anywhere you will need another flywheel, so make sure you verify that first before machining anything.

Good luck!

93M6Formula

Cool thanks! The new flywheel looks to have the balance pad on it so I should be good to go!

BALLSS

you might want to contact CC clutch and ask them if there is a orientation to mount their clutch to a stock FW since it does not have a paint dab on it. Mine did not either (CC 2.5) but again I had mine neutral balanced for my internal balance motor.

My sense is CC and most all replacement clutches I see except CenterForce don't have a paint dab and also are the China clone PP and not Valeo (OEM). These China clones don't have the balance drill holes on the outside edge of the mating area of the PP so I doubt they are exactly the same balance of OEM. With that said people slap these replacement clutches in all the time and with a stock FW balance everything should be fine.

You may find removing the PP and turning it 180 degrees and remounting it will resolve your issues although it is a PIA to go through this process.

Also your vibration may not be clutch related....confirm you are not grounding somewhere (exhaust hitting something or bad tranny mount)

What FW did you put in?

Jason94z

iTrader: (3)

Do you know if you lined up the extra hole on the flywheel with the extra hole on the crank shaft?

If you did then call CC like the guy above said and ask then how to align the pressure plate, maybe that's all it was.

If you can't remember or be 100% sure you aligned the extra hole I bet that was your problem.

93M6Formula

I'm pretty positive it's clutch related, because it only started after I replaced the clutch and flywheel. I know it isn't the trans because I just put a new one in after I did the clutch because I lost 2nd gear...lol

The flywheel is just an Advance Auto stock replacement.

93M6Formula

There's only one way the flywheel can go on with the dowel located in the end of the crank so I'm 100% sure it was correct.

I'll give CC a call and ask if they need to be oriented a certain way.