396 flex plate removal - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Richard Dobson · 02-13-2008, 07:27 AM

When removing a BB flex plate do you need to mark it and the crankshaft to keep the balance correct? I'm being cautious because it's my first attempt at working on a auto trans setup. Thanks

Bus Ted Knuckle · 02-13-2008, 07:34 AM

RIchard, it should only go on one way. There will be a post sticking out of the crank that fits in a corresponding hole in the flexplate.

71big block · 02-13-2008, 07:34 AM

No, it can only go on one way, the dowels and bolt holes only allow for one position.

Richard Dobson · 02-13-2008, 10:11 AM

My flexplate doesn't have any locating pins, it just has 6 bolts that hold it onto the rear of the crankshsft flange. It has places welded onto it that I think are for balancing, do I need to mark it so that I can put it back the way it comes off. Is it balanced with the engine is my concern? By the way it looks like it may be difficult to get off the crank hub that goes thru the flexplate flange so I put some WD40 on it. Any tips as to how to get it off in case it is stuck?

Longhorn Man · 02-13-2008, 12:07 PM

a 396, if stock, is internally ballanced, so if you are able to turn it, it won't matter.
If it is stick on the crank, a rap on the edge of it with your hand should pop it off, if not, a hammer would be OK.

Richard Dobson · 02-13-2008, 10:29 PM

So, if it is repositioned it won't matter? Right?

72 CustomCamper · 02-14-2008, 08:21 AM

The bolts are slightly off center. It is the same flex plate as an internally ballanced small block...

Chuck

slammed1 · 02-14-2008, 09:08 AM

The info above is correct. 396 shouldnt have a counter weight flex plate or harmonic balancer. Also not having a dowel means that the bolt holes will most always have a pattern that they will only bolt up one way.......rotating the flex plate on the crank will allow you to see which pattern will line up all 6 holes at the same time.

02-13-2008, 07:27 AM	#1
Richard Dobson Registered User Join Date: Apr 2003 Location: Easley, South Carolina Posts: 491	396 flex plate removal When removing a BB flex plate do you need to mark it and the crankshaft to keep the balance correct? I'm being cautious because it's my first attempt at working on a auto trans setup. Thanks __________________ Richard Dobson

02-13-2008, 07:34 AM	#2
Bus Ted Knuckle Son of a gun Join Date: Jan 2007 Location: Hot Springs, Arkansas Posts: 1,636	Re: 396 flex plate removal RIchard, it should only go on one way. There will be a post sticking out of the crank that fits in a corresponding hole in the flexplate. __________________ Bill BEATERS ARE NEATER

02-13-2008, 07:34 AM	#3
71big block 1971 GMC 3/4 ton, 572 CID Join Date: Aug 2007 Location: Green Bay, WI Posts: 293	Re: 396 flex plate removal No, it can only go on one way, the dowels and bolt holes only allow for one position. __________________ 71 GMC 3/4 572 CID, 1988 GMC 1/2 2006 Saturn Vue "We always have parts left over on a job this size"

02-13-2008, 10:11 AM	#4
Richard Dobson Registered User Join Date: Apr 2003 Location: Easley, South Carolina Posts: 491	Re: 396 flex plate removal My flexplate doesn't have any locating pins, it just has 6 bolts that hold it onto the rear of the crankshsft flange. It has places welded onto it that I think are for balancing, do I need to mark it so that I can put it back the way it comes off. Is it balanced with the engine is my concern? By the way it looks like it may be difficult to get off the crank hub that goes thru the flexplate flange so I put some WD40 on it. Any tips as to how to get it off in case it is stuck? __________________ Richard Dobson

02-13-2008, 12:07 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: 396 flex plate removal a 396, if stock, is internally ballanced, so if you are able to turn it, it won't matter. If it is stick on the crank, a rap on the edge of it with your hand should pop it off, if not, a hammer would be OK.

02-13-2008, 10:29 PM	#6
Richard Dobson Registered User Join Date: Apr 2003 Location: Easley, South Carolina Posts: 491	Re: 396 flex plate removal So, if it is repositioned it won't matter? Right? __________________ Richard Dobson

02-14-2008, 08:21 AM	#7
72 CustomCamper huh ??? Join Date: Nov 2002 Location: Fredericksburg,Va. Posts: 3,368	Re: 396 flex plate removal The bolts are slightly off center. It is the same flex plate as an internally ballanced small block... Chuck __________________ 90 Blazer Silverado 350w/ 700R4 and 32" Kelly's "I am a bomb technician. If you see me running try to keep up!"

02-14-2008, 09:08 AM	#8
slammed1 1972 Chevrolet SWB Join Date: Jan 2008 Location: FT Smith AR Posts: 512	Re: 396 flex plate removal The info above is correct. 396 shouldnt have a counter weight flex plate or harmonic balancer. Also not having a dowel means that the bolt holes will most always have a pattern that they will only bolt up one way.......rotating the flex plate on the crank will allow you to see which pattern will line up all 6 holes at the same time. __________________ My New thread with pics (not my build thread yet.) http://67-72chevytrucks.com/vboard/s...46#post2573646 1972 Chevrolet 1/2 ton short wide bed,68 frt clip Project. 1980 Camaro Inherited when father passed,68K Miles 2003 Ford Mach1 FUN as Hell!! 2002 Dodge Ram 5-8 slam Rolling BillBoard (Gone not forgot) 2004 Dodge Ram HEMI 10" lifted on 37's and 2wd.

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