2nd Broken Flex Plate

I haven't confirmed it yet, but I'm 80% sure that I just broke my 2nd flex plate! I'm wondering if any of you other L67 owners have broken ANY flex plates yet? Assuming I have broken another one, as it has all the signs, I am NOT going to put on a 3rd stock flex plate. Does anyone have any suggestions other than the $400 Mezier plate ZZPerformance has? And, assuming this IS what has just happened, I will be pulling the 2.93 sprockets out and going to 3.29's at the same time. I don't need 140+ mph, that's just KRAZY stupid.
Since we don't have a transmission forum here, this is where I posted it. Why don't we have a driveline forum?

Never had the flex plate break yet, but you might be racing it a bit more than I do.

what exactly is the flex plate?

The flex plate connects the engine to the torque convertor, and has the starter ring on it. They told me the starter torque is what broke the 1st one. I think 50+ extra hp broke this one, if that's what it is. I haven't confirmed it yet. Had to go to a benifit dinner for our Pastor. He has luekemia, again, after 20 years. He is 32 with 2 young kids. He is going to Mayo Clinic Monday. He is half Korean, and a bone marrow transplant is the ONLY real cure for this, and the chances of finding someone compatable is zero to none.
Maybe tomarrow afternoon I can pull the inspection cover and take a look. 

the flex plate is what connects the engine to the torque converter.
 
It's a big plate that is bolted onto the engine, and it has teeth all the way around.  The teeth are there for the starter to crank the engine and turn it over.  The flex plate connects to the torque converter with 3 bolts.
 
I think I have a picture of the flexplate somewhere... let me look and I'll post it up.

Confirmed what I thought I was hearing, a broken flex plate. #2. This one is broke differently than the 1st, I believe. The 1st was broke in a starburst pattern. This one, I just plain ripped the center section out, it appears. Here is a pic of at least 3 broken sections:

If 290hp did this, what is more going to do?
I found the wink link!

Damn, it would take a good bit of torque to break that thing. Just hope that if you get a stronger flexplate that you dont just break something else in the tranny.

Then I guess I'll find the next weak link.

Just a thought for ya but have you had the balance of your torque converter checked.  That caused my buddies in his grand prix to go out.  Was 1.5 oz off.  Just somthing you might want to check when ya have it torn down.

Torque convertor is brand new last fall. GM warranty replacement. Probably CRAP. Good idea on the balance. I'm wondering if it was mis-installed, somehow.

Unless they have the capability to do a catscan on the plates before they are installed, shiznick like that happens when you are going for performance.
 
Like I've said before, torque converter are very simple mechanical devices.

quote:

Confirmed what I thought I was hearing, a broken flex plate.

Can you describe, in a nutshell, what it SOUNDS like? I am curious as to whether or not maybe that is what caused my tranny issue and improper gear ratio code last week....

It sounds like a loose fan blade rattling, especially at idle with no pressure on it. No noise under throttle until it is about to let loose.

---

I ordered parts today from ZZPerformance. Talked to Tim. He said that the next thing to go will be the transmission input shaft unless I change the torque convertor to a lighter unit, ie, theirs. I trust them, so I bought a new 2500rpm stall torque convertor along with the Meziere flex plate. Total including shopping, just undet $870.
ZZP is saying, unless I'm misunderstanding, that this convertor will shave 1/2 second of my 1/4 mile time, with only this mod. They are EIGHT pounds lighter than stock!

Link:
https://www.zzperformance.com/grand_prix/products1.php?id=133&catid=105
Cost of labor in this project to be between $520 and $600 depending on who I have do the install. So there goes my intercooler money, but maybe this is for the best, if it saves my transmission, at least for a while.

You're right. They help, considerably. But don't you have to drop the tranny to install the converter? Please let me know how that goes Wayne! =) I'm excited for you! Glad you turned lemons into lemonade.

quote:

ORIGINAL: RocknSS04

 
ZZP is saying, unless I'm misunderstanding, that this convertor will shave 1/2 second of my 1/4 mile time, with only this mod. They are EIGHT pounds lighter than stock!

 
HOLY SH!T!!!  That is awesome!!!!  Definately worth it for a full 1/2 second.

  Yes to dropping the tranny, but the motor stays in. Been there, done that once before. That's why the $575 to install. I'm also doing another tranny service, changing the filter and switching to Dextron IV, per ZZPerformance.
  If this is true about the 1/2 second, yes, I DID just turn lemons into lemonade. I don't feel quite so bad about spending the $1,500 if it helps the performance THAT much.
  Going to do a full service, too: rotate tires and oil change. Thursday, it looks like.
  Still looking at installing the intercooler, roller rockers, pipes, and dyno tuning this spring. Then it will be time for a RACE trans', because this one will probably go BOOM!

Actually Space, I am NOT doing this myself. My Chevy dealer is going to do it, and loan me an Impala overnight, if need be. Thay are as competative as most garages, and I have been working with this service mgr for 10 years now. 
I was hoping my parts would be in today, but no luck.

how much power are you putting down to be break the flex plate?

quote:

ORIGINAL: RocknSS04


If 290hp did this, what is more going to do?

Im going to guess around 290 horse power? ;)

  As it says, no parts are available. Doesn't matter if they said they were in stock. Doesn't matter If They charged my credit card.  THEY DON'T HAVE WHAT I BOUGHT IN STOCK. They are telling me 10 working days before the flex plates ship from California, and the torque convertors they have, but they aren't powder coated yet, and a week or so before that's done.
  I talked to Brian at Intense Racing, Steve at Certified Transmissions, who builds ZZP's tranny's, and Roger at R & B Performance in Niles, and ALL of them said basically the same thing: I didn't break my flex plate, it was mis-installed! Of course, since I've modded my car, GM won't stand behind the warranty, so I'm SOL. Everyone says there was probably a locating dowel not installed, loose bolts, or something else improperly done. So, I have no parts, and now I can't have my dealer do the install, just because.
  Where do I stand? Steve said his tranny in Zoomers GP (ZZPerformance) is cranking out 900hp (9.01 in the 1/4) on a FACTORY flex plate. Intense is over 600hp on theirs with a factory plate. Nobody said I NEED this Meziere plate, and it's 1 lb heavier than factory. The ZZP 2500 stall convertor I still want, cuz it's 8 lbs lighter than stock. So the plan is the new lighter convertor, factory flex plate, and 1 of 2 local installers to put it in, in about a week or so.

quote:

ORIGINAL: vita

quote:

ORIGINAL: RocknSS04


If 290hp did this, what is more going to do?

Im going to guess around 290 horse power? ;)

sorry I missed that