ACE1252

Question....

Here is the white X on my old flywheel and the yellow dot on the old pressure plate....fairly cut and dry on which hole to line them up....



So which hole do I go with here on my new flywheel and new pressure plate???



I guess I just pick one on either side of the X and try it.....and experiences or comments on this???

PoorMan

I would take it back to the store and have them pull another one.

ACE1252

Well, I've just put everything back together. I put the red mark on the right side of the white X(just like in the above picture). My test drive had a bad vibration start around 4500 and go all the way to redline.

I'm going to call Valeo Monday and ask them about the yellow dot and what it means. I hope they have some info for me. Otherwise, I may have to pull this tranny up to another 5 times.....rotating the pressure plate around the flywheel until the vibration goes away(if it goes away with this pressure plate).

I'm also going to ask them about this Autozone knock off pressure plate and how it stacks up to their pressure plate. I will post up what they tell me.

Green96Z

When I did mine, I got a replacement flywheel from AZ, but it didn't have a mark on it. What I found by searching was to put the yellow mark (which is for balancing by the way) as close to the flywheel locating pin as possible.

Chevycobb

^ I sure hope so, that's how I just bolted mine up anyway

ACE1252

I do have some more information.

I called Valeo and their tech support confirmed that the marked side(yellow dot) of the "LT4" pressure plate is the LIGHT side of the plate. I do remember seeing this info on the board somewhere, but this confirms the info.

They had no information on what the white X means on the LT1 flywheel. He said he could speculate, but didn't want to as not to tell me wrong.

He said that Valeo checks the spin balance of their plates and the spec is 20 gcm max.

I did take the Duralast plate and spin it 180*. So the red mark is opposite the white X on my flywheel. Upon my test drive, the vibrations were much worse. They started at 2000 and magnified until I stopped at 4500rpms(too scared to go any higher it was so bad). They were so bad that I could not only feel, but hear the out of balance condition at 2000 rpms and on up.

Tonight I'm going to pull the tranny again....I have gotten so good at this I can have it out in about an hour. I'm not sure if that's good or bad.

I'm going to try and see if I can feel the vibrations with the tranny out of the car and the pressure plate bolted up. My gauge has been how much vibration I can feel through the shifter stick, so I don't know if I will be able to tell too much(but I know when it's right). If I can't work this out, I plan on buying a genuine Valeo LT4 plate.

I know that I'm not the first to post up complaints on the balance of the Duralast plate.

Heck, I may ask Valeo if I can ship this Duralast plate to them for testing. I'll be glad to pay them to test it....just to see how balanced it is.....

Chevycobb

im guessing the duralast is the Chinese version?

where was it in relation to the locating pin? I haven't finished mine yet. I can't seem to find one of the trans. to bellhousing bolts

ACE1252

Just got the tranny out.....took 40 mins....lol.

The white X on the flywheel can be anywhere around the flywheel. It is in different spots on the two I have....and I have a third stored in my attic(actually it's the first one....the one in the top pic is 2nd, and the lower pic is 3rd...the one I just bought). I wished I could say for certain what the X on the flywheel means, but I can't.....and there is nothing mentioned in the factory manual about it.

The only thing I know for certain about the flywheel is that the weights on the old one must be transferred to the new one in exactly the same positions(referencing the location pin).

The mark on the pressure plate can be yellow, white, or red. Those are the different color markings I have seen.

Chevycobb

damn, now you got me doubting my install. guess we'll see how it goes when I stop being lazy and finish it. I remember mine a long time ago having that X on the flywheel, but didn't even think to look where it was supposed to be on it now, because there is certainly no X on it anymore. guess it wore off

Green96Z

I think the weights on the pressure plates are for zero-balancing, which the PP SHOULD be. Take it to a machine shop and have them balance the PP. A seriously out of balance one would definitely give you a vibration, no matter which way it faces.

Another thought on the marks on the PP and flywheel are that maybe the PP is weighted opposite of the mark on it, so that when the marks are aligned, the weights on the PP somewhat counterbalance the weights on the flywheel (since the flywheel has weights on it to balance the crank). Just a thought. Either way, I would definitely avoid putting a cheap "Made in China" pressure plate in mine, and stick with the Valeo.

ACE1252

I've located an Automotive Machine shop in Greensboro that can dynamically balance flywheels.

The pressure plate has no weights on it(neither the Valeo or Duralast). The flywheel does(the ones you transfer from your original flywheel).

I'm going to remove them and have the shop spin it up to see if the white X denotes a heavy or light side of the flywheel. Once we know where we stand with the flywheel, they are going to bolt the pressure plate to it and spin it up.

I'm dropping them off tomorrow, so I may not know anything until next week.

ACE1252

I dropped both the flywheel and plate off today and learned something from him that was actually staring me in the face.



These flywheels are not neutral balanced from the factory(for some reason I thought they were). See this huge weight cast in at the top of the flywheel? That is part of the weight system that balances the stock LT1 crank, pistons, etc. They are balanced to some type of spec, but it is not neutral.

He was going to use the the flywheel as a jig to bolt up the pressure plate....but with the flywheel not being neutral balanced that idea does not work.

He is going to see if he can locate a neutral balanced flywheel with a bolt pattern that will match to the LT4 pressure plate. Hope to have more information soon.

Chevycobb

well I fired mine up today, using the locator pin as apoint for the dot, and didn't have any unusual vibrations. atleast none that were there before but I think its gotta come back out now anyway because I think my clutch for is hitting the PP

good luck getting yours going again

ACE1252

Machine shop is taking too long for my schedule....so I picked up my parts. Turns out they could not find a flywheel to use as a fixture in order to check the balance the Autozone pressure plate . They need a neutral balanced flywheel and the LT1 flywheel is not neutral balanced.

I've got a genuine Valeo clutch kit on the way.

This is what I'm going to do with the Autozone plate. My Dad does own his own machine shop(self employed). I'm going to take my oldest LT1 flywheel up to him and have him machine off the cast in weight on the back of the flywheel. This will allow me to get this flywheel neutrally balanced. Once that is done, they can check the balance quality of the Autozone pressure plate.

I'll post up what happens with my Valeo clutch install.

I honestly wonder if I'm a victim of SLP's good work. I say that because this LT4 plate I currently have is an LT4 plate with holes drilled around the perimeter of the clutch surface. Here is a picture of it.....



They neutral balanced the assembly by drilling material out of the plate at these 3 locations around the plate....



With that, I wonder if they balanced it much better than stock. I don't know. At this point, I think the LT4 Valeo knock offs at Autozone, Advance, etc are not balanced very well. I'll find out once I get my genuine Valeo LT4 kit.

FYI, I got the Valeo kit on ebay from here.....

http://cgi.ebay.com/ebaymotors/VALEO...Q5fAccessories

$280 shipped with the "stock" GM disk is not a bad price for a genuine Valeo LT4 unit.

ACE1252

Did you drive it or just rev it? You will not know until you feel it through the shifter around 2000-4000 on up. Just revving it, for me, didn't reveal any issues.....however it's a very different story when the input shaft is engaged under load.

I have read that flywheel/pressure plate balance issues show up in vibrations through the shifter.

Quote from this check sheet.....
"Notes: Clutch, Flywheel, and Trans Problems Tend to be Felt in the Shifter"

http://www.tracyvette.com/vibrationdiagnosis.html