Thread: flexplate balancing/install

been a while since ive posted in here, so my car is manual, it uses a flywheel, its being balanced to match the 3.8sc flexplate so i dont throw balance out, but with that being said when you install a flexplate on the stock gtp tranny i notice there is an oblong hole, same with my flexplate, how do you install it so you make sure your balance isnt say 45 degrees out? ended up getting nasty vibration from my flywheel after reinstalling the origional that was in the car for 1.5 years

The oblong hole fits only one direction. You shouldnt be able to instsll it incorrectly.

theres like one hole thats off and out of alignment with the rest. you need to spin it on the crank till all the holes line up perfectly.

you can eye ball it to see the thread/bolt hole patterns.

bill some how got one bolted on wrong and it vibrated like mad. it was 180º off iirc.

okay that probably happened, we ended up drilling that oblong hole bigger to fit the bolt and that probably threw off the balance

you can bolt is up wrong, but the bolts are super tight to the flex or flywheel. with all bolts in it should wiggle back and fourth a little bit.

so basically i bought a new flywheel and got it all machined just to have a spare

after you burn the first clutch its nice to have 1/2 the new parts on hand already???? glass 1/2 full? lol

The holes aren't perfectly symmetrical. So you shouldn't be able to bolt it up wrong. That being said.. I had one that someone put on for me and a hole or two was egged slightly. Start all bolts by hand and run them almost all the way in by hand. Second part of that is where I went wrong lol

Holler if you wanna see that vid.

nah im fine bill, mine shakes the dash from idle to 3000 rpm, when we re installed it after snapping 2 bolts we drilled it for ease of install, there was my mistake lol, and yea gunna finish the fleywheel and just have new parts for when i swap clutches, thanks for the info guys, couldnt find much on google :P thought id pop by for a quick visit

Trett...I've broken or seen nearly everything 3800 related broken. just ask

yeah been way too long since ive been on here normally i just go to the facebook groups where i see dsmuts all the time haha, going turbo soon with a grand national t66 from turbonetics, will probably have pics and lots of questions as i dont know alot about turbos/kits