neat

I've begun the McLeod twin disk install on my stock bottom end 1991 and have run into a problem getting someone to match balance the new flywheel to my old dual mass. I've called a dozen machine shops and none of them have even heard of match balancing a flywheel, let alone know how to do it.

My initial plan was to have the new flywheel match balanced to my old dual mass, and the new pressure plate (with out the disks) zero balanced. This is the correct procedure from what I gathered on the forum and the directions that came with the clutch. Did I interpret this correctly, or did I misunderstand something?

Since I live in an area that is devoid of a machine shop capable of match balancing my flywheel, what options do I have? Should I remove the stocker and ship it to a machine shop along with my new flywheel? Could I skip this step and install the clutch and flywheel without balancing? Should I attempt to get the entire assembly zero balanced?

Thought's?

EDIT: 4/24/06 I now know the actual answer to this question thanks to Bill Boudreau of www.zfdoc.com and Gene from McLeod. The flywheel comes from McLeod balanced to GM spec, which is 32 grams out. The stock dual mass has holes drilled in the outer ring around it's entire circumference. These holes exist to facilitate the balancing of engines that require more or less than the 32 gram standard set by GM. Apparently, due to the nature of assembly line style manufacturing the occasional L98 or LT1 would need more or less than the standard 32 grams counterweight. If you remove your stock flywheel and find that none of these holes are filled with metal inserts, you're new flywheel should not require balancing as it has been weighted the same as the stocker. If there are weights inserted in the holes, you will need to have the new flywheel matched to the old.

The pressure plate should have a neutral balance. Mine was within 5 grams, so I chose not to remove any weight from it. My machine shop did not have the capability to spin only the pressure plate, so they bolted it to the McLeod flywheel and spun it. The initial measurement when balancing in this fashion was a staggering 65 grams out. However, when attempting to neutral balance the pressure plate, it is important to either spin just the pressure plate, or be sure it is bolted to a neutral balance flywheel. The McLeod flywheel is weighted 32 grams out, so bolting the pressure plate to it simply added to the already out of balance reading. The machinist corrected this problem by removing the pressure plate from the flywheel, spinning just the flywheel and adding clay to it until it was neutral balanced. Effectively eliminating the 32 gram counter balance built into the wheel by McLeod. After attaching the pressure plate to the newly neutral balanced flywheel, the reading came back as 4.XX grams. In my opinion, the 4-5 grams wasn't enough to worry about, especially since I don't ever plan on spinning the motor beyond 6000 RPM's.

I will install the clutch this weekend and report back.

danno85

The way that is done is you mount the two flywheels together on the mandrel, but exactly 180 degrees apart (using the dowel hole as a reference as well as the pressure plate mounting bolt holes), then you balance the "assembly" by removing/adding weight to the new flywheel. When done, you have two flywheels with the same amount of counterbalance.

Explain that to your local machine shop(s) and see if one of them will do it then.

Dan

pablocruise

One way to use a clutch assembly that is zero balanced is to use a motor that has been fully internally balnced to zero.
The crankshaft has material removed or added in the places indicated by the balncing machine. Usually a harmonic balancer that is zero balanced is also used on that crank.

You mentioned your motor was stock, that means it is externally balanced.

I would think shipping a 45lb DMFW and a new FW around to different shops would get expensive, plus it's much better if you are there in person to explain to the guy what needs to be done.

Tell us about the McLeod FW. Is it aluminum or steel or iron or ????
Does it include a bolt-on weight mass and small weights for fine tuning?
I am not familiar with the McLeod kit. I only have their clutch disc(Kevlar).

LT4POWR

I thought the McLeod Street Twin kits were sold ready to bolt-on?

bogus

no. There are no bolt on flywheels.

You see, GM used the DM as the final fine balance for the LTx motor.

They would course balance the DM, then mount it to an engine, run it to find the balance, and add the little weights... or something to that effect.

If you look at a DM, on the outer edge, there is a series of small holes, these holes are used to replicate the balance. You buy a new DM, buy a set of weights, and proceed to put weights into the same holes as are on the original DM.

What would be neat is if the aftermarket manufacturers would simply copy this method. Many already have prewieghted them... put the holes in so we can fine tune and 90% of these problems would go away.

comp

neat

*sigh*

The search continues for a machine shop.

The flywheel is aluminum.

bogus

I am still stunned that you... in the heart of NASCAR can't find a place to balance that sucker.

Stop by the DEI shops... never know.

neat

Unfortunately, I do not follow Nascar, and I am from Montana. I do not speak the dialect here, I do not know the secret Nascar password that identifies me as someone worth trying to help, and anytime I try to explain what I want done I am invariably, "A damn Yankee trying to tell him how to do his job."

I was reffered to a machine shop in Durham by Jeff Creech of Carolina Auto Masters, but they won't be open again until Monday. And it's 100 freakin' miles away. I can't believe I can't find someone local.

I was really hoping to get the car squared away this weekend, but I guess it will have to wait.

Thanks for the advice, and the explantion as to how to match balance was great. Maybe if I explain the procedure, I'll get somewhere.

bogus

pick up a fake southern accent.

I am suprised they consider someone from Montana a damned yankee. That is odd.

then again, being from Delaware, I was looked at as the long haired hippy freak... and *all those *** wipes in the south would say [fake southern accent] "How can I help you ma'am?" [/fake southern accent]

ugh.

*Disclaimer: I don't mean to imply "all" southerners are *** wipes, far from it... just those that talked to me in the way described above.

neat

Lol, you're gonna run into butt heads no matter where you go in the world. The South is no different.

bogus

that is so very true....

LT4POWR

from the McLeod website...
"Note: All flywheels are balanced to factory tolerances. If you have a blue-printed or specially balanced engine, please balance new flywheel to those special specs."

Bluewasp

you can buy the Street twin to what they call a "GM balance". If I remember correctly there are 35 grams of weight added to a stock dual mass.

CMYC4GO

The way the shop balanced my flywheel (just last week) was setting them side by side, and adding the balance weights in the appropriate holes, but that was on a Luk flywheel.

LT4POWR

I bought the McLoed ST kit w/ the Al flywheel. I'll check tonight, but I think the instructions said something like "the kit is shipped ready to bolt-on".

blown87

Well you have figured out the ground rules, that is a start.

some one local should be able to help you out, once they understand what you need done.

If not, you can ship it to the machine shop we use here in Atlanta and have it done for you, PM me if you want there contact #.

bogus

for all of you beleiving that these FWs are balanced... when I did the SMFW a couple years ago, I went against my better judgement and beleived Tom when he said that the Fidenza is already balanced for the LT1...

Explain the vibrations at 3200 RPM on up...

Dynabob

As a life-long Durham resident I'd be interested to know what machine shop you were refered to.

neat

I just got off the phone with Gene from McLeod. He says that the flywheel I have is made to GM specs, but that GM did balance each flywheel individually. He recommended I check the back of my flywheel for drill marks. If my stock flywheel has an excessive amount of material removed, then I should definitely have the new flywheel match balanced. If the stock flywheel has little to no material removed, I should be good to go.

Gene also said that 90% of the time people install the clutch/flywheel without match balancing and have no problems. The 10% that do have problems are the 10% that had an excessive amount of weight removed or added to the stock flywheel from GM.

I am going to check out my flywheel tonight and go from there. If there is only a couple of dimples in the stocker, I am going to bolt the new one in and go.

Wish me luck!