TH350 or Flexplate trouble

Howdy, have any of you guys ever have a flex plate crack so badly that there is no longer any power going from the engine to the trans?

I have a '57 Chevy 1/2 ton on a later ch***is, small block (prob. a 350) w/a TH350, 2.42 rear end. The front end is lowered a bit, and I think that I might have bounced the inspection cover off of one of the numerous speed bumps on the campus where I work.

For the last couple of weeks I'd been hearing a buzzing rattle while coming off idle when pulling out from a full stop, which would then go away once I was at crusing speed (25 mph+). Well, the noise got a lot worse over the weekend, but I was stuck with driving this 'cus my daily is in the shop ( caught in a flash flood last week ).

Last night, I pulled out from an intersection, got a few yards down the road, and suddenly no power from from my engine, which is still running.

I did a search for "cracked flexplate", but didn't see this same situation described. Any body ever heard of anything like this?


Thanks in advance, *****6

 

Sounds like a possible broken input shaft. Jack it up and take a look.

 

Not necessarily the flex plate to crank bolts, although I have had them crack through, but have you checked the torque convertor to flex plate bolts? I have seen them come loose too and fall out....If thats the case, get new ones and lok-***e them in....

 

or fluid lines could be pinched causing not enough fluid to get from the cooler in the radiator to the trans thus frying the trans,,,,

 

Yep, it happens often, first a small rattle, then a loud rattle, then no drive. Fortunately, flex plates are cheap, and they're not too hard to change. The bolt circle spins out and leaves the torque converter stationary. Move the transmission back about 3 or 4 inches, and bolt a new flex plate on. It takes a good transmission shop an hour or so to get you back on the road.
Jerry

 

Yeah, I just had to do one in my dad's C10(the 2nd one in his truck) and I had one go in my old C10. Cracked completely around the bolt circle. Supposedly it is more prevelant on the 80+ motors(from what I was told). Thinking of trying an aftermarket one the next time.

 

or the pump grenaded

 

Can you crank the motor with the starter?

If the flexplate is completely broken out, the starter shouldn't work either....should it?

 

exactly as he said..

 

no it will not crank
broken flex plate ..no cranky
engine will not turn over
if the engine cranks and starts..(turns the engine over) than i would suspect input shaft to the trans..or trans pump..or possibly all the bolts came out of your flex plate (ring gear) to your torque converter

 

Unless you have a front mount starter...

 

I have had a flex plate crack, but i investigated the noises before it all let go. Result would be no drive and unable to restart. I have also seen torque convertors where the bolts have come loose and drive is lost but car still starts as flexplate is intact.

 

I doubt thats the case here

 

Square one would be to check the fluid cold then running. May be the pump or fluid level? Low or severly burned fluid? Is it moving?
Just an easy check before you jack the car up.

Edit: and for what it's worth, I run a daily without an inspection cover. None of it hangs below the oil pan so nothing coming from the front end will get up in there very easilly. I did make a few steel straps that cross under the flexplate to keep a critter or something unlucky enough to get in there from wrapping up. Easier starter access and i hope it cools a little better.

 

I was hopeing that no one would take me serious...

Hell, I guess there must be such a thing... lol

 

If the dowl pins are missing in the back of the engine block,your new flex plate will crack again!

 

jajajaj i just had to ..i figured you were playing but sometimes ..you never know.

 

Thanks for all the input. It sounds like if I go home and try to start it, and the engine won't turn over, then that's a good thing in this case. If it does start, then I may have something worse than a bad flexplate wrong with it.


We'll see. *****6

 

let us know how this turns out

 

O.K., now I'm really confused. Went home kinda late last night, cranked it up, settled into a nice idle, and it went in both forward and reverse. I didn't want to take it out on the road, but now I'm concerned that trying to drive it any further will only cause more damage.

?????? *****6

 

well it sounds like the ring gear is still intact..probably your pump going out..or something internal that might need to be adjusted changed or cleaned

 

what is the fluid level like?

 

Sounds like the filter is plugged. Drop the pan and replace the filter, of course if this works it means the ****** is hurt and you just put a bandaid on the problem. Was it making a whining noise before? That would be the pump trying to **** up fluid thru a plugged filter.

 

I dunno. I'll be getting in after dark tonight and will hafta leave out early in the morning. Guess I'll hafta find a working flashlight to take a look later tonight. This is starting to sound like a visit to the trans shop is in my future.


Dang it. *****6