ok here is the deal. I just rebuilt the motor about 4000 miles ago, and she's been running really strong. But last night I started hearing this god awful noise (thought I spun a bearing again). First thing I did was jack it up and do an oil change. Results were nothing out of the ordinary- no metal shaving whatsoever. Got back on the road, and within less than 1 mile the noise came back. Suddenly, the RPMs SHOT up to about 4500 like theree was no load on the motor, and the car didnt accelerate (kinda like the tranny slipped). Upon pulling into a parking lot and killing it, I tried to start it again. The starter turns but it doesnt appear that the engine is turning over.
What I thought was FLEXPLATE. I thought something had happened to that (that would explain the clanging noise, followed by the slipping, and finally- the engine not turning over even tho the starter is turning. So i took the inspection cover off of the tranny to check out the plate. It APPEARS to still be connected to both tranny and motor. I put a 19mm socket on the crank pulley and turned it by hand. The flexplate turned also (thats a good thing). But then I had dad turn try using the keys to start it and the flexplate turns with the starter, but the crank pulley and everything else stayed still. WTF????? I thought maybe the crank broke (crying) but that wouldnt explain why pulley and flexplate both turn together by hand, but not when using the starter....what gives??
Someone please help me. TIA

Wow. you're line of thinking was the same as mine, now I'm as confused as you.

I'm thinking that the flex plate is no longer secured to the crank - no idea how, but it makes sense out of everything EXCEPT the fact that when you turn the crank, the flex plate moves. However - I think this is because moving the crank has more resistance then moving the flex plate. when you turn the crank by hand, the flex plate still has some frictional contact (at it's broken junction?) with the crank, so it moves because there isn't much resistance to the flex plate moving. But doing the opposite, ergo moving the flex plate, there is not enough friction between the flex plate and the crank to overcome the resistance of the crank moving the pistons up and down, the accessory belts, etc...

I seriously think you will have to unbolt the tranny from the block, and see what's happening where the flex plate is attached. It will be interesting to see what happens

I've never heard of a cracked crank in a 420a - so I'm really thinking it's at the flex-to-crank junction.

I'd say you broke your flexplate. The input shaft of the trans is what is holding it up/on for now, its just resting on the input shaft, because the clutch is still bolted to it. A broken flexplate is not unheard of. I would highly doubt a broken crank. Time to pull the trans :)

Sounds to me that you may have broke the ring gear from the flex plate. But you still going to have to pull the trany out to see.

ok..so i was on the right track with the whole flex plate thing. That makes me feel a little better. But what is the ring gear? I've pulled the motor and found that pretty easy, but dont know the first thing about yanking out a transmission. Would it be eeasier for me to pull the motor again to do the fix....or attempt pulling the transmission?
....I'd like to try to fix it this week coming up. OH yeah...and where could I find another flexplate (possibly a lightened one like the flywheels they make for manual transmissions?).

I strongly suggest replacing it with the PA RACING nhra approved flexplate. It's actually heavier then the stock flexplate, welded the entire 360 degree circumfrence, and it's spec 29.1 which is nhra's regulation flexplate (in case you ever compete in a pro-class)

http://www.howellautomotive.com/Howell/Store/catalog/catalog/product_info.php?cPath=21_113_126&products_id=484

That's listed as for a neon, but our cars take the same one. I just put mine in today along with the 3spd

Well to answer your first quistion. The ring gear go around the out side of the flex plate that's what your start engauges to start the car.And for the second quistion did you pull the motor and tran out at the same time? It sound to me like you did if you can do that I would. But if you can get the car up high enuff it would be easier to just pull the trany out from the bottom. Hope that helps GOOD LUCK.

No I didnt pull both at the same time. I just pulled the motor and left the tranny in place. I can get the car up pretty high if needed, to just drop the tranny or whatever, I just dont know what all I have to do to disconnect it from the cv joints, driveshafts, or whatever...
I barely knew what an intake manifold looked like before I did the engine rebuild, but now I feel pretty comfortable with all the stuff I had to do. Just never attempted to tackle anything transmission related yet. I saw the flexplate Howell Automotive has, and I was just considering raising up the car, disconnecting everything needed to yank out the engine, and then droping it down about 6 inches or however much I need to, to change out flexplates, then jack it back up into place. Would this work? I just don't know if I'm up for the job of messing with the actual tranny and all that stuff

well, I hope this is of help to you as I type this out.. here goes

to pull the tranny is actually pretty simple. Start by pulling out your intake/battery, as well as the battery tray. Unbolt the starter. To remove the axles, take off the wheel, then the axle nut, then the bottom of the pickle fork as well as the top, the tie rod end and the lower control arm and sway bar. Lift the hub assembly off of the axle, go up by the tranny itself and use a flat head screwdriver against the small slots to get the shaft out of the clip, once it breaks past the clip it'll slide right out.

Now remove the bottom crossmember by unbolting the front roll stopper mount, the 2 17mm bolts up front, and the 2 14mm bolts in the rear. there will be 2 brackets that go from the trans to the oil pan area, remove those, then remove the inspection cover on the flexplate. Turn the crank and remove all your converter bolts (total of 4). Make sure you mark the flexplate so you now how it goes back together. Take off the rear roll stopper mount next, and then unbolt the side tranny mount. Take out all the bellhousing bolts left in the trans holding it to the motor. It will first need to slide towards the driver side, then slightly towards the front of the car, and then down. The motor will be suspended by the pass. side mount and that's it, so I suggest bracing it up once you have the tranny out.

Either the motor or the trans is going to have to come out to replace the flexplate. I can't see you getting enough room in there to undo the 8 or 10 bolts on the crank, and then lining up the new flexplate will be damn near impossible. Plus i'd want to inspect the converter as well to make sure it hasn't pulled any threads on the bolts in that or anything, so it's best IMHO to just pull the trans.

All in all it's not to difficult. I had my old tranny out, and the 3spd modified to go in in roughly 1.5 days (had to make brackets and what not), so in and out could be done in a day with ease.

If you want, I'll actually copy step for step from the service manual, but that was just off the top of my head.

Thanx that sounds pretty easy. Ive got the dsm cd manual, just hadnt looked at possibility of yanking tranny instead. Now that I've read that I may attempt it that way tho. especially since half of that is already done. Crossmember inspection plate etc...already removed. just have to unbolt bellhousing and do the whole axle thing. Thats the part I was most concerned about cuz I know nothing of FWD axles and the such.
Hopefully I'll be ordering that sfi approved flexplate from howell this week or next. I hate being without my car.