Flexplate - The 1947 - Present Chevrolet & GMC Truck Message Board Network

elorenzof · 01-29-2021, 11:50 AM

Good Morning,

Building this truck is fun but you gotta remember the little things... I installed the Engine on the frame (rebuilt engine), Flexplate to the engine, the Trans to the engine (rebuilt trans), and the Transfer case to the Trans (rebuilt xfer case).
I went to bolt on the flexplate to the torque converter and i think i installed the flexplate backwards... I know im dumb. When i went to install the 3 bolts the torque converter is about a 1/4 inch further away and the bolts are not long enough now to reach from the flexplate into the torque coverter. I can use a small prybar to move the torque converter forward into the flexplate but with resistance. The flexplate, the mounting "tabs" on the 3 flex plate bolts are indented toward the engine instead of indented out toward the torque converter. I'm at work now but did i install the flexplate backwards? I'm doing a frame up build so instead of unbolting the transfer case and trans i could just unbolt the bolts from the bellhousing to the engine and my two engine mounts and lift the motor out.

sick472 · 01-29-2021, 12:11 PM

I'm pretty sure the flex plate mounting bolt pads ('tabs") should be humped towards the torque converter. I this IS the case (somebody back me up here), know that the flex plate may have a lip around the center hole that may have been "smushed" inward towards the crank hub. It may be hard to get off the crank if it has deformed and wedged onto the crank hub. Not that is too hard to get off, but you should consider getting a new flex plate in case your has deformed from being put on backwards.

**kwmech** · 01-29-2021, 01:06 PM

Personally I don't get how this happens so often. My father-in-law who was a mechanic for 40+ years did this not too long ago. "How in the he... did you manage that"?? was my comment to him. If you push this on without bolting it down, I don't think it would even be flat on the back of the crank because of the sharp edge/lip on the center hole. But whatever, pull the engine and look for distortion on the plate

morepwr · 01-29-2021, 03:09 PM

Quote:

Originally Posted by sick472

I'm pretty sure the flex plate mounting bolt pads ('tabs") should be humped towards the torque converter. I this IS the case (somebody back me up here), know that the flex plate may have a lip around the center hole that may have been "smushed" inward towards the crank hub. It may be hard to get off the crank if it has deformed and wedged onto the crank hub. Not that is too hard to get off, but you should consider getting a new flex plate in case your has deformed from being put on backwards.

You are correct. You can actually put it on backwards but will smash that lip in the process of torquing it down.

mr.mud1 · 01-29-2021, 03:36 PM

hi,you have the flex plate in backwards as already reported.a 100 years ago,i worked in a little transmission shop and the main guy there had a trick for changing broken and cracked flex plates.i had a 4x4 blazer came in one day with a broken flex plate and was dreading taking 1/2 the truck apart to get to it but what i saw him do,was take out the bolts that bolt the motor to the trans,one at a time,replace each one with a 3/8's bolt about 2 1/2 or 3 inches long.i'm don't remember but i'm sure he took off or loosened trans mounts,convertor and whatever else but pushed the trans back on the long bolts,got his skinny little hands up to the flex plate bolts,removed them and the broken flex plate,replaced everything the new parts,buttoned it all up and on the road again.might save you a little work?

Redneck Rydes · 01-29-2021, 05:17 PM

Probably the best thing to do is replace the plate and when you put it back in always the bumps toward the torque converter.

**dmjlambert** · 01-29-2021, 08:01 PM

Quote:

Originally Posted by elorenzof

...I'm doing a frame up build so instead of unbolting the transfer case and trans i could just unbolt the bolts from the bellhousing to the engine and my two engine mounts and lift the motor out.

mr.mud1 is correct, you don't need to take the engine out. Just remove the flex plate and put it back in using longer bolts to slide the transmission back a little bit. Here's a detailed thread with pictures. http://67-72chevytrucks.com/vboard/s...d.php?t=736181

01-29-2021, 11:50 AM	#1
elorenzof Registered User Join Date: Nov 2017 Location: Anthem AZ Posts: 281	Flexplate Good Morning, Building this truck is fun but you gotta remember the little things... I installed the Engine on the frame (rebuilt engine), Flexplate to the engine, the Trans to the engine (rebuilt trans), and the Transfer case to the Trans (rebuilt xfer case). I went to bolt on the flexplate to the torque converter and i think i installed the flexplate backwards... I know im dumb. When i went to install the 3 bolts the torque converter is about a 1/4 inch further away and the bolts are not long enough now to reach from the flexplate into the torque coverter. I can use a small prybar to move the torque converter forward into the flexplate but with resistance. The flexplate, the mounting "tabs" on the 3 flex plate bolts are indented toward the engine instead of indented out toward the torque converter. I'm at work now but did i install the flexplate backwards? I'm doing a frame up build so instead of unbolting the transfer case and trans i could just unbolt the bolts from the bellhousing to the engine and my two engine mounts and lift the motor out. Attached Images

01-29-2021, 12:11 PM	#2
sick472 Registered User Join Date: Jul 2015 Location: Sedalia Mo. Posts: 1,131	Re: Flexplate I'm pretty sure the flex plate mounting bolt pads ('tabs") should be humped towards the torque converter. I this IS the case (somebody back me up here), know that the flex plate may have a lip around the center hole that may have been "smushed" inward towards the crank hub. It may be hard to get off the crank if it has deformed and wedged onto the crank hub. Not that is too hard to get off, but you should consider getting a new flex plate in case your has deformed from being put on backwards. __________________ He who is without oil shall throw the first rod. Compressions 8.7:1 1972 C10 1976 C10 (parts truck) 1985 K20

01-29-2021, 01:06 PM	#3
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,628	Re: Flexplate Personally I don't get how this happens so often. My father-in-law who was a mechanic for 40+ years did this not too long ago. "How in the he... did you manage that"?? was my comment to him. If you push this on without bolting it down, I don't think it would even be flat on the back of the crank because of the sharp edge/lip on the center hole. But whatever, pull the engine and look for distortion on the plate

01-29-2021, 03:36 PM	#5
mr.mud1 Registered User Join Date: Dec 2020 Location: Joggins Nova Scotia Posts: 1,597	Re: Flexplate hi,you have the flex plate in backwards as already reported.a 100 years ago,i worked in a little transmission shop and the main guy there had a trick for changing broken and cracked flex plates.i had a 4x4 blazer came in one day with a broken flex plate and was dreading taking 1/2 the truck apart to get to it but what i saw him do,was take out the bolts that bolt the motor to the trans,one at a time,replace each one with a 3/8's bolt about 2 1/2 or 3 inches long.i'm don't remember but i'm sure he took off or loosened trans mounts,convertor and whatever else but pushed the trans back on the long bolts,got his skinny little hands up to the flex plate bolts,removed them and the broken flex plate,replaced everything the new parts,buttoned it all up and on the road again.might save you a little work?

01-29-2021, 05:17 PM	#6
Redneck Rydes Registered User Join Date: Feb 2016 Location: Trenton,Ontario & South Carolina Posts: 755	Re: Flexplate Probably the best thing to do is replace the plate and when you put it back in always the bumps toward the torque converter.



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