Meziere Flexplate Balance

**buford1972** · 06-14-2015

I’m curious if anyone else has had a situation with a balance issue and/or torque convertor bolt pattern when using a Meziere flexplate. I currently have a rebuilt L67 from my 2000 GTP on the engine stand. I had the machine shop balance the reciprocating assembly using a new Harmonic damper and my stock flexplate. While picking up the parts from the machine shop I was told that they did not have to remove or add any weight from the stock flexplate. I later decided to purchase the Meziere 340A “stock balance” flexplate. “Everything should be the same” is what I thought. While taking some clearance measurements for a set of ARP bolts to attach the plate to the crank, I noticed that the convertor bolt pattern on the flexplate was smaller than on my stock rebuilt convertor. I contacted Greg from Meziere and explained my concerns. He recommended sending both my stock plate and the Meziere plate to him and he would have the machinists take a look. At that time the website listed the plate as having a dual convertor pattern. Greg verified the website information about the dual pattern and said that mine may have slipped through by mistake but the drill of the second pattern would be performed at no charge to me. About a week later I talked with Jerry who was taking over for Gerry who was on vacation. He stated that this plate was not offered with a dual pattern and the website was not accurate. The website has since been updated. He stated that the new plate would be drilled free of charge but the machinist wanted to verify which plate was balanced to my reciprocating assembly. I told him that I used my stocker to which he replied the balance weights between the two were different. The machinist matched my new plate to the old plate balance free of charge also. It seems that the Meziere plate is set up for the L32 Series 2 engine only. Is it true that the L32 engine has a different balance compared to the L67? Does the L32 convertor use a smaller bolt pattern? I thought the L32 and L67 were both the same in that regard. If so, the Meziere plate would not be a direct bolt on for the L67 engine / trans combo. Any thoughts on this??? BTW, Meziere provided top notch customer support and were very helpful.

**Turbocharged400sbc** · 06-14-2015

the meziere is an early "NA" or L36 flexplate. never seen em with the large bolt pattern and ive done 4 of em.

yes they are balanced to 20 oz/in and yes they should be rebalanced to the sc settings which vary across the years and ranges from 21-22 oz/in

counterbore yer crank bolt holes to 5/16ths at 3/16ths deep (cheap HF step drill works great, file down the sharp edge of the 1/4" step so it wont cut away your threads) and use the arp ford (clutch) pressure plate bolts to bolt it to the crank, much nicer and better than the std 5/16ths arp bolts.

two on the left are the precision m10x1.0 converter bolts and the OEM m10x1.5
the three on the right are the "std" small 3/8ths hex/12point arp 5/16ths bolts offered by venders, to the right of it is the ARP ford pressure late bolts with 1/2" 12 point head, large underhead dia, longer shank length, and the OEM flexplate to crank bolt on the right

i swear this is like the 3rd or 4th time ive posted this info, probably should be put in the archives

**buford1972** · 06-14-2015

Great! Thank you for the information and advice about the bolts.

**SgtMarshal** · 09-20-2016

if an L36 torque converter is being used, is there any need for a rebalance on the flexplate?

**Turbocharged400sbc** · 09-20-2016

Wat

the balance refers to the engine rotating assembly from harmonic damper to flexplate.
Our engines are externally balanced which means the harmonic damper and the flexplate are imbalanced to bring the total rotating assembly into balance

**Turbocharged400sbc** · 09-20-2016

If you're referring to read drilling the bolt pattern for the torque converter it is already set up for the smaller 245 millimeter bolt pattern of the na converters

**SgtMarshal** · 09-22-2016

Originally Posted by Turbocharged400sbc

Wat

the balance refers to the engine rotating assembly from harmonic damper to flexplate.
Our engines are externally balanced which means the harmonic damper and the flexplate are imbalanced to bring the total rotating assembly into balance

I was trying to make sense of your previous statement, this clarifies it for me, thanks.

when I put the built dynotech transmisison in a few years ago, I also installed a zzp l36 tc, and to make it work we elongated the holes of the L67 flex plate. the bolts loosened up because the holes got more elongated, and now the flexplate needs to be changed. we tightened the bolts last month, but I would rather not give them a chance to fail cause other problems.

**b4black** · 09-22-2016

So would any of this have to do with a problem I have? After cracking to stock flexplates on my '02 GS, I went with a Meziere flexplate and ARP bolts from Intense. During installation, I found out about the L67 torque converter not working and replace it with a stock type L36/L26 replacement.

The new flexplates/torque converter combo seem to make a noise at light throttle like it's unbalanced. It's been that way for a while now. It hasn't gotten worse, so I've been living with it.

yes they are balanced to 20 oz/in and yes they should be rebalanced to the sc settings which vary across the years and ranges from 21-22 oz/in

How is this done? What would an '02 GS setting be?

**buford1972** · 09-23-2016

My solution was to contact Meziere directly. They had me send my flexplate back to them and drilled the new plate to match my SC convertor. They also rebalanced it to the stock SC specs. They obviously knew my situation which makes me wonder why they dont have both convertor patterns already drilled and two seperate plates, one for NA and one for SC engine. Between discussing it with them, sending my plate in, them performing the work, and getting it back, it took about a month. I also had to come up with a solution for the crank bolts that wouldnt have heads so thick that they touched the back of the convertor AND were long enough to make me happy. All in all it was a bit of a learning curv but the trade off is that they performed the work and sent it back to me for free.

**b4black** · 09-23-2016

Thanks, that helps.

I had a transmission shop install mine (about the only work I haven't done myself). Didn't find out about the TC pattern thing until they had the trans out. Luckily they figured out what was wrong and could order the NA TC same day.

Most people buying this flexplate are using it behind an L67 engine. None of the vendors selling these shares any of this important information. Which is super f***ing irritating. It cost 8x the stock flexplate, plus the new TC and now to get it right, I'd have to pull it again and send it back to get balance. Argh!

**SgtMarshal** · 09-23-2016

Originally Posted by b4black

Thanks, that helps.

I had a transmission shop install mine (about the only work I haven't done myself). Didn't find out about the TC pattern thing until they had the trans out. Luckily they figured out what was wrong and could order the NA TC same day.

Most people buying this flexplate are using it behind an L67 engine. None of the vendors selling these shares any of this important information. Which is super f***ing irritating. It cost 8x the stock flexplate, plus the new TC and now to get it right, I'd have to pull it again and send it back to get balance. Argh!

I think a few vendors make a stock flexplate that is drilled for both tc's. you are probably better off having the better flexplate anyway.