Last 2 summer repair projects

[Don in VT]

Hi All,

I have 2 more repair projects on our 90 ZR. First is to replace the dual mass flywheel (DMF) and the harmonic dampener (HD). Last year when I replaced the clutch we checked the FW rotational distance and compared it to the FSM spec. It was in spec. We decided that since we did not have a new FW at the time of the clutch job we would buy the FW and do the job later.
Well, now is the time.

We are also going to replace the HD as it runs slightly out of concentricity and causes the belt tensioner to flutter. With a strobe, it is possible to see the slight wobble.

My question here is only concerning the FW. I would like to understand the balance issues when FW is repaced. My new flywheel is OEM and came off a 90 new crate LT5. The FW does have have bored holes of different depths on the OD of the FW. There are NO balance plugs in the holes. When I get the old FW off , how do I get the balance weights out ? Are they screwed in or pressed in or ???. I wonder how many owners just bolt the new FW in and be done with it,

I am trying to get all the summer projects and needed repairs done as we are planning on putting the ZR up for sale within a couple of months and I want the car fixed for the new owner. We are expecting that the sale of the ZR will probably take a long time and we are planning for that.

Any tips, help, on the FW issue will be appreciated.

Cheers,

Don in VT

[Don in VT]

Hi All,

I want to thank all that read my post. The subject of the FW being balanced to the parent motor is understood only by a few so I guess that I missed sharing in their experiences. I will pass on what info I can when we do the FW R and R.
If appropriate, I will take a pix or two of the process and pass on the results when we hit the road with the new FW.

Have a great late Summer and Fall.

Save the wave

Don

[USAFPILOT]

I previously owned a 96 LT4 to my current ZR-1 and when having a new clutch installed they installed a new DMF which vibrated like all hell. I showed them the old flywheel that had the weights installed in it and had done some research to find the LT4's were all balanced externally when the engine was built. You needed the proper combination of the FW weights and whatever is on the other side of the motor, the balancer I guess. Once they installed the FW weights into the new DMF it smoothed out. You would think a Chevrolet Dealer would know how to change a clutch on a Corvette, but they dont always know, and are not always capable of reading the tech manual either. If I remember correct they even tried to resurface the original DMF which is also a no no.

[Hammer]

The Chebby dealer I just took my car to for an AC problem (no cold air) told me I was out of Freon and wanted $580 to swap to 134r. Ended up being the low side AC cycling switch. They also aligned my '98 GMC truck and when I got the bill, at the bottom it stated I needed a pitman arm. WTF, you're kidding me right, this is a certified dealer.

I eventually got the $75 troublshootng fee for the AC and the $39.95 alignment charge back from them.

[Jagdpanzer]

Here is a photo of the FW that came out of Yun's car over the weekend.
This is the first chance I've got to see a FW with a trim balance weight installed. From what I can see extracting the old weight would be difficult without destroying it. Better off having a couple of new trim weights standing by if needed to install in the new FW when you tear it down.

[jcruz]

Originally Posted by Hammer

The Chebby dealer I just took my car to for an AC problem (no cold air) told me I was out of Freon and wanted $580 to swap to 134r. Ended up being the low side AC cycling switch. They also aligned my '98 GMC truck and when I got the bill, at the bottom it stated I needed a pitman arm. WTF, you're kidding me right, this is a certified dealer.

I eventually got the $75 troublshootng fee for the AC and the $39.95 alignment charge back from them.

My local Chevy dealer charges $95 per half hour.

Needless to say, I won't go there.