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1995 Pontiac Firebird formula w bolt ons
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Discussion Starter · #1 ·
95 Firebird formula. Lt1 with 4l60e. Cold air intake, and complete msd ignition with multi spark box so nothing crazy. Was cruising about 60 and lost all gears so I pull over on a side road and Shut the car off, tried starting it again it would just crank.kinda had a off sound to it . Got it towed home and when I finally got around to messing with it I noticed when I turn it over just the converter and flex plate spin. Not the motor. The motor still turns fine by hand. Any ideas? I had a friend tell me that I most likely blew the tc. Any suggestions help. Most likely gonna end up dropping the subframe tonight or tomorrow.
 

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Flexplate spins but not the engine? I cant imagine how the flexplate could seperate from the crankshaft without falling off. I cant imagine shearing the bolts... I need to know more about this issue. I am super interested to find out what the deal is. Have you removed the inspection plate to try the flexplate by hand or to see if it somehow became unbolted?
 

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Because torque converter is bolted to flex plate, if flex plate to crankshaft bolts came out, the starter would turn flex plate & torque converter and not the engine. The torque converter is not only bolted to flex plate, but is aldo indexed to input shaft of trans.

I would remove bottom inspection cover and turn flex plate by hand. Have assistant looking at crank pulley to see if engine turns .
 

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1995 Pontiac Firebird formula w bolt ons
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Discussion Starter · #4 ·
Flexplate spins but not the engine? I cant imagine how the flexplate could seperate from the crankshaft without falling off. I cant imagine shearing the bolts... I need to know more about this issue. I am super interested to find out what the deal is. Have you removed the inspection plate to try the flexplate by hand or to see if it somehow became unbolted?
Yeah I had more time to mess with it last night. The flex plate and tc spin over by hand while in park. The flex plates nearly split in half lol. I’m assuming the whole middle section sheared clean. Not the bolts themselves. So what all should I expect to have to replace for this? I’ve already started the process of dropping the subframe and all. I should have time to finish this weekend but should I expect to have to replace the trans as well?
 

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1995 Pontiac Firebird formula w bolt ons
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Discussion Starter · #5 ·
Because torque converter is bolted to flex plate, if flex plate to crankshaft bolts came out, the starter would turn flex plate & torque converter and not the engine. The torque converter is not only bolted to flex plate, but is aldo indexed to input shaft of trans.

I would remove bottom inspection cover and turn flex plate by hand. Have assistant looking at crank pulley to see if engine turns .
The engine turns by hand when I turn it at the crank. When I turn the starter or turn the fly wheel by hand it’s not cranking the motor so I’m assuming it’s either sheared the bolts or the middle section of the flexplate sheared off.
 

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Im pretty sure your only option is to remove the transmission and replace the flex plate at this point. Wow. Thats crazy man.... never heard of that happening. Might want to check out the transmission pump while you are at it. Would be a shame to bolt back a busted tranny.
 

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1995 Pontiac Firebird formula w bolt ons
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Discussion Starter · #7 ·
Im pretty sure your only option is to remove the transmission and replace the flex plate at this point. Wow. Thats crazy man.... never heard of that happening. Might want to check out the transmission pump while you are at it. Would be a shame to bolt back a busted tranny.
Yeah I’m dropping the whole subframe and going at it that way. I’m gonna go with one of the pioneer ones from oreillys. I’ll keep you updated. Thank you for the help guys
 

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Discussion Starter · #10 ·
Yeah I finally got the time to actually tearing into it. Hopefully I’ll have some more time this weekend to mess with it some more and finish the tc up.
 

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Did you actually drop the subframe? Mine came out with not a lot of problems just pulling the transmission. Had to get the car high to get it out from under it but not a big deal.

Al in Tucson
 

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Discussion Starter · #12 ·
Did you actually drop the subframe? Mine came out with not a lot of problems just pulling the transmission. Had to get the car high to get it out from under it but not a big deal.

Al in Tucson
Yeah I did for headers, water pump, the flexplate and to freshen up the wiring and a few other things so it was just easier to drop it since I was gonna have to take it all apart anyways.
 
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