[mgarblik]

I did my best to try and read and understand everything in this thread. I have to admit, I don't fully understand everything that happened, when and by who enough to make a recommendation that I know will fix it. So, if I was faced with this situation and was committed to make it right, I would do the following. Your probably not going to like this. I would remove the engine and and the crankshaft. Have the crankshaft zero balanced +- 2 grams and verify. That completes the engine. Then I would buy a steel zero balance flywheel and a zero balance clutch. Problem solved. Time consuming and possibly a little expensive, but now it's fixed. Mixing, matching, drilling, bolting , welding, guessing, removing, installing, you may get lucky and hit the right balance, but it may be an even more time consuming exercise than just biting the bullet and doing it all one more time, correctly. I wish you the best. Very frustrating I am sure. I hope you get it.

[MPKind]

Originally Posted by mgarblik

I did my best to try and read and understand everything in this thread. I have to admit, I don't fully understand everything that happened, when and by who enough to make a recommendation that I know will fix it. So, if I was faced with this situation and was committed to make it right, I would do the following. Your probably not going to like this. I would remove the engine and and the crankshaft. Have the crankshaft zero balanced +- 2 grams and verify. That completes the engine. Then I would buy a steel zero balance flywheel and a zero balance clutch. Problem solved. Time consuming and possibly a little expensive, but now it's fixed. Mixing, matching, drilling, bolting , welding, guessing, removing, installing, you may get lucky and hit the right balance, but it may be an even more time consuming exercise than just biting the bullet and doing it all one more time, correctly. I wish you the best. Very frustrating I am sure. I hope you get it.

It's a series of events that involved 2 clutch sets (Centerforce & McLeod), 2 flywheels ('65 & '75 factory pieces), 2 shops (Wheeler Racing and Midwest Transmission), 3 trans RnRs to date.

Engine was well balanced with the '65 FW and HB by Wheeler Racing. Worked great.

It was assumed that both the '65 and '75 FWs had factory balance. I'm not so sure about that now given the huge difference in behavior.

The PP on the McLeod had weights added and removed 2 times! Could that cause issues? Maybe.

The trans shop tried to neutral balance the '65 FW by drilling into the factory holes and adding 3 more, so I have no clue what they removed vs what was already removed by Pontiac. To this day I don't know what possessed them to modify a flywheel.

To date there's been 4 different FW and PP combos

1. '65 Factory FW with Centerforce PP (factory neutral balance). Worked great.

2. '65 Factory FW with McLeod PP (2 large washers welded to it). Bad vibrations at idle and beyond. FW was not modified at this point. I think they tried to neutral balance the FW/PP combo not knowing it was supposed to have a slight imbalance.

Here's where my car went from a buddies shop to the transmission shop.

3. '65 Factory FW with McLeod PP. This is when they drilled into the FW to neutral balance, then ground off and welded back weights on the PP to neutral balance the FW/PP assembly. This combo had the least amount of vibration of the 3. When I received the car, I was not told they drilled into the flywheel. I assumed they only removed the weights from the PP to restore it's original balance. In a phone call a week later it was revealed the flywheel had been drilled. After a week of arguing with the shop owner about it, the car went back to the trans shop.

4. '75 Factory FW with McLeod PP (all added weights removed). This time it was balanced dynamically at Wheeler Racing. The combo did not produce. Vibration above 2500 rpm and beyond. Worse than combo 3.

It's a guessing game now. Could try the '75 FW with the Centerforce PP Attempting a 5th combo vs. engine/crank removal? The trans can go in and out in a day, the engine work will take way more time and money. So far the trans shop covered 2 RnRs, but that can't go on forever.