Cavi

woops, the pictures are on one of the other threads that are linked to this one, read through it and read all the link threads that are listed one of them shows a stock DM next to a SPEC single mass with the weight attached very clearly so you can place yours, don't suffer for nothing. It seems to me that you can't be doing any good to the tranny either with the vibrations, not just the engine

inedajob

Read the info from "bluewasp" in this thread!

http://forums.corvetteforum.com/c4-t...ve-3k-rpm.html

TIP:
Do NOT push the weights in all the way so you can remove them more easily. YOu need to remove them to try the different trials and find which one works best for your car.

If you decide not to push in the weights all the way make sure the weights aren't going to hit the trans/bell housing as the engine spins. Just put the car in 6th gear and turn one of the rear wheels.

radar502

Keep the duel-mass if you can...I have 96LT-4 with 135,000 miles replaced with dule disk set up SHAKES RATTLES and NOISE..The old guy Corvette mechanic said the old flywheel was in good shape and I should keep it in ( he tells me this after he puts the new stuff in ) THANKS..after about 4,000 miles it's now starting to smooth out ,on the one I have no balancing no nothing just put in out of box..but not cheap eather People tell me that the one I have is the good stuff so I guess anything less will be worse..I have a frend he has a Corvette road race shop and said mine is the best cluch seen in a wile ..I thinking the rest must realy be bad...I would keep the duel mass if street ride... Most HOT RODERS guys girls don't care a little shake raddle and vibe is ok.. My cluch story do what you will...Mclead duel street around $1200-1300 install $500.00 not cheap for buzz raddle a vibe but leave two 12in black marks for days... Come around and do it one more time ...

96GS#007

The dual mass flywheel has weight that is cast in place. This is because the one-peice rear main seal engines are *externally* balanced at the rear using the flywheel or flexplate (in the case of the autos) from the factory. The old two piece rear seal cranks had the weight cast as part of the crankshaft where the flywheel bolts on.

The single mass replacements have a weight that is removable. If you build an engine and it requires a neutrally balanced flywheel, like my 383, you do not use the weight. If you are replacing a dual mass flywheel on an otherwise stock engine, you bolt the provided weight in place.

Regarding the Blue Wasp thread....*Some* engines had vibration issues after assembly. As a result, the factory fix was to add some *additional* weight to the perimeter of the flywheel. This was a trial and error exercise to fine tune the balance. The VAST majority of ZF6 speed equipped cars did NOT require this.

You have a vibration because you didn't use the weight that came with the single mass flywheel. Your otherwise stock engine is significantly out of balance. This is a fact. Continue running it in this manner and you will be replacing main bearings. The addition of this weight does not require multiple tries. You bolt it in and go.

Here is a pic of my dual mass next to a SPEC single mass flywheel. The cast in weight is circled in red. You can also see the weight that is bolted in place on the SPEC flywheel.