legacycentral bbs

Hey dudes.....this account is new cause i havent posted here in awhile and i forgot my log in name and stuff...so its good to talk to you guys again.....so down to the issues...i just bought a 90 ls sedan w/ an automatic and the motor wont turn over but the starter is good and the flywheel turns with the starter......help please....thanks in advance!!!!

Are you sure the motor isn't turning over?

If the inside of your crank pulley is destroyed, the crank might be spinning even though the belts won't move. You could also pull a spark plug and have someone crank it over (with the coil unplugged!) while you look in the plug hole with a flashlight, just to confirm or deny your suspicions.

Otherwise, if the crank truly isn't spinning and the flywheel is, you would have to have all the flywheel bolts broken/gone, a broken flywheel, or a snapped crank. All of the above are highly unlikely.

Broken flexiplate?

the motor turns over when i turn the crank pulley bolt(and seems to have compression) but not when the starter/flywheel turns.....what and where is the flexiplate??

Flexplate = flywheel.

ooohh...got it...havent rippied it apart yet but the flywheel seems in tact but im not sure what a broken one looks or feels like...has all its teeth and is secure in place when i tried to wiggle it around w/ my had or a screw driver

Because the torque converter is so heavy they do not need a heavy flywheel, so they use a thin metal plate instead.

They call the thin plate a flexiplate.

The flexiplate bolts to the back of the crank and the torque converter bolts to the plate.

They often work harden and get brittle then get a crack that runs right around the outside of the bolts in the crank and if it gets bad enough the plate will stop driving the torque converter around.

You may not be able to get any movement out of it when you poked it with a screwdriver because it's still attached to the torque converter, which is still attached to the gearbox.

Unfortunatly it's pretty hard to see in there. It sounds like the motor or the gearbox is going to have to come out to confirm it's the flexiplate, but, if it isn't the flexiplate then I think it could only be a broken crank and the motor is going to have to come out any way.

I'd pull the motor.

never pulled one of these motors...is it harder than pullin the tranny...tho i have pulled a 5 speed out of my last Leg.

IMO pulling the auto trans sucks major ass compared the 5spd.

what is the major differences????

Probably the fact that a auto is heavier and you want to avoid the TC from letting go off the trans and having to reseat it. Either way you will probably have to reseat it actually.

Its easier (and faster) to pull the motor. Anyone know if the torque converter/flywheel would be able to move forward/back if it were broken at the bolts? I think it might. It definately shouldn't if its not.

Pull the engine. I once replaced the auto tranny in my 90 wagon and it was a shitty experience. No fun at all and the transmission nearly fell on my arm about 10 times in the process. It weighs a ton.

I never ever want to replace the tranny in one of these cars again and if I do I think I'll take the motor out first.

I'd imagine you might get about half an inch of forward and aft movement if the plate is broken.

For the backyarder pulling the motor is probably easier. It generally depends whether you have a concrete floor and trolly jack and whether it's turbo or not.

If you do pull the trans, the torque converter can just stay on the gearbox which can stay on the trolly jack(if it's a full sized one), so you won't need to struggle. Pull it back then jack it up till the trans just touches the floor pan and it wil not wobble off if you bump it. You need to keep the electrical plugs from being crushed too I remember!

You can get at the flexiplate from above once the trans is moved. For that matter, you can get at the flexiplate once you have slipped the motor forwards a little. I remember doing a clutch on an older model once with no tools hardly and I did it by slipping a greased board under the motor and sliding it forward enough to change the clutch; using a mirror to align things. You won't need to align things.


In this case though, where the two likly problems are broken crank or broken flexiplate it would be sensible to remove the motor in case it is the crank.

so i think it is decided.....im goin to pull the motor.....now i gotta get my brother to let me use his picker!!! just wondering...would anyone be interested in a write up w/ pictures????

OK....so i pulled the motor forward about 5 or 6 inches and the torque converter/flexplate stayed with the motor...is this normal and how do i remove it to replace it???

It is if you didn't remove the four bolts that hold the torque converter to the flexplate. Its okay to pull the motor this way if you can, but pay attention to the drive tube that connects to the torque converter if you do. The torque converter/flexplate bolts can be accessed through the hole on the top right of the engine.

what should i look out for w/ the shaft....and i havent taken those bolts off...thanks for the info man...

You could damage that shaft. I'd suggest removing the four bolts and leaving the torque converter with the transmission.

The other thing to note is that getting the torque converter shaft to reseat itself correct can sometimes be a pain.

hmmm.

converter is still bolted to flexplate.

if it's following the engine, the flexplate must be at least somewhat intact.

Does the flexplate turn with the front pulley? Are you pulling your motor just because your starter has a bad bendix or pinion gear? hook some jumper cables to your starter and see what happens.


EDIT: I re-read your post, you state that the flywheel is definatly turning with the starter. Continue, and good luck.

well this is what is funny...when i first got the car before i ripped into anything, when i would turn the crank pully the flex plate would try to turn but not make any actual rotation....now that it is pulled away from the bell housing they move as if they were attached....well im off to finish taking her apart so i will let you know when i know more...thanks! OH, and i replaced the starter when i got the car thinkin that it was the problem...it wasnt so returned it the next day...by a stroke of luck, they still had my core starter which i got tested and it worked properly!

Its sounding more like a broken crankshaft.
If the drive tube comes out w/ the torque converter (it probably will), attach it to the torque converter then reinstall together. As Josh stated, it would be better to unbolt the t/c before removing the engine.

ok...well was the flexplate...since i couldnt get one today i welded up the broken one but i dont think im gunna run it....if i was to put the welded flexplate back on, how long could i run it before breakage/if breakage?

For the work involved and due to the fraility of flexiplates at the best of times, I'd replace it.

It should be at least somewhat balance, also.