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Discussion Starter · #1 ·
Yesterday I'd planned on R&R'ing my flexplate as it was cracked (again). Had an appointment in the morning and the rest of the day off to get all the work done.

On the way home, the transmission starts slipping, pull over, get one last hard engagement and then have a top speed of about 2 MPH, I assume from parasitic dynamics. Have essentially no forward or reverse gears and engine behavior seems to be disconnected from the transmission. First observed symptoms to total failure was less than a mile.

I'm operating under the assumption that the transmission is toast and it's not a failure of the torque converter (though my understanding was that if the torque converter went the transmission was gone)

I'm currently looking at my options, either going the junkyard route, local rebuild, non-local purchase or 6-speed.

Chances are I won't be doing anything for a month or three anyways while I save money (unless I go junkyard route or find one super cheap).

I guess if I go 6-speed, I don't need to worry about the flexplate.... :)
 

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A yard tranny will get you on the road the cheapest-quickest. Flexplate is not supposed to be a periodic maintenance item. cwm1 When you have it apart it will pay to find the root cause or you might end up needing several trannys as spares eh.
It'd take at least a month or two to round up all the T56 parts you need if trying to go the least expensive used route, and even that will be several times more $$$ than an auto.
 

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Discussion Starter · #3 ·
It was tossed out on the MCML that perhaps I've got a torque converter that was ballooning causing it.

I'll be picking up a transmission / tc from a member here that's semi-local for reasonable $ to get by on until I can properly address the issues.

The flexplate was an el-cheapo Pioneer from Autozone, so I wasn't sure if perhaps it was poor quality (it was only $30 or 40) or if there was something in the driveline that was causing the issue.
 

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Did the noise from the cracked flexplate increase, or even increase and then decrease noticeably? My first experience with this was in a 72 Camaro and we thought the rattle was bottom end engine noise. Had another engine about ready when one day the car got louder, then almost silent...and stopped moving. As if the engine was disconnected from the trans...and it was!

The TC slid back just a bit when the flex plate split completely away at the crank around the bolts and that was that. Every so often she'd bump and stumble forwards at a couple MPH. Well, I'd finally figured out that obviously my "engine noise" was a tranny noise, that or the back of the crank fell off(that crossed my mind but not a busted flex plate?). Was amazed when we got it apart, but a new plate fixed everything.

At least till that one broke. Car ate the things and we never did figure out why, which is why it found a new home.
 

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Discussion Starter · #5 ·
That certainly describes most of what I experienced. Over the two or three days previous to the failure, the noise from the flexplate became significantly worse. I don't recall any noise from the flexplate when things quit working, but I was revving it up high enough to where it wouldn't have been making noise anyways.

I just checked - started it and looked underneath - and the torque converter is spinning. Still rolls forward in reverse though. When it cools down later today I'd planned on checking valve clearances on the 914, but I'll throw the jack under the Impala and pry back to see if it's broken from the hub while I'm out. That would be a pleasant find, but I'd think I'd hear some metal on metal engagement unless it's just sliding smoothly off the crank bolts or something.

For whatever it's worth, park (and neutral) work as expected. (Or the slight nose down attitude has kept it together and from rolling into the street....)
 

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Park is a pin that engages the transmission, and the transmission is connected to the rear, so that is normal operation.
 

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I have a 4l60e from Monster Transmissions for you

Hey bowman I have a brand new tranny from Monster Transmisions, heavy duty stage 2 shift firmness chrome pan with drain plug, handles up to 500 horses. I got stuck with it never installed in my caprice still strapped to pallet the way it came. invested $1350.00 in it. will take less for it if you want it, its also has replacement warranty. let me know maybe we can make a deal? (251) 721-0736
 
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