flexplate

joehalford01

joehalford01

Active member
Joined
Sep 6, 2008
Messages
27
Location
Visalia, CA
So, how in the heck do I figure out which flexplate my car has besides crawling under the car and counting each tooth on the darn thing? Every corvette supplier online dosn't list the tooth count of their flexplates and Napaonline does but they offer 168 and 153 tooth. So....what the hey? Anybody know? This is a 1980 L-82 with a th/350 automatic. What did they come with stock? I'm leaning towards an unweighted 168 tooth based on what I'm seeing but that would be a guess. :(

Also, any recommendations performance wise? Should I go with a heavier flexplate or a lighter flexplate? Or should I just stick to the cheap stuff? I'm willing to part with more money for better parts but only if there would be a tangible benefit. Thanks!

Oh yeah, I have to replace it because when my last starter died it decided to engage really slow one last time and tear up some teeth. It's my daily driver so I'd like to order the right part before I pull the transmission. :drink:
 
My money is on a 168 tooth. I am quite sure my 81 used that. Frankly, they are just so common, just pull it out and go get the part. Any parts store will have it in stock. If not, any tranny shop would.
Unless your going huge HP, a stock one is fine. Figure about $35.00.
 
I believe that's the 168 tooth flex plate. Rather than counting teeth measure the diameter. According to Jegg's: 153-tooth ring gear flexplates are 12.85'' diameter, 168-tooth ring gear flexplates are 14.13'' diameter.

Although the flex plates are interchangable, the starters are not. Also, don't go with the cheapest, go with a quality piece. You don't want to pull the trans again because you tried to save a couple bucks on a cheaper flex plate....
 
Ok cool, thanks for the tips guys. I'll give it a measure. I'm considering buying a nicer one from summitracing so I want to order the right one from the get go and minimize my down time. I'm still undecided on whether I want to have my buddy do it for me at his shop or if i want to do it myself. He wants to charge me around $400, which dosn't seem too bad considering how much aggravation it might save me.
 
It's not even necessary to measure the diameter - just look at the starter bolts - if they're staggered (both long bolts), it's the 14" diameter 168 tooth flywheel (flexplate); if the bolts are inline (one short/one long), its the 12 7/8" diameter 153 tooth flywheel (flexplate).

;)
 
just a few more bolt to torque down to finish this same job

mine is a 82 and took the larger flexplate, i had just changed heads and intake on my car and the stock starter just couldn't handle the new compression...damaged a few teeth and so i had to change it out. While i was in there i replace the tail mount mount with a new ploy unit and installed a gear reduction starter to handle the new found compression.This job isn't too bad to do if you wanna save that 400.00 and put that moo la somewhere else on the car. in fact i didn't have to drop mine out of the car.I just had to remove the bellhousing bolts, the t.v. cable i unhooked from the carb.,along witht the speedo cable,pulled the trans. fill tube.Unhooked the drive shaft @ front yolk and moved to one side undone tail mount,torque convert bolts and just moved it back a few inches with wood between the floor jack and the trans. pan to get to the crank -flex bolts afterwards just walked the trans back up in place and started the first two lower bell housing bolt back. Nope not too bad at all....
 
Miss Mako said:
mine is a 82 and took the larger flexplate, i had just changed heads and intake on my car and the stock starter just couldn't handle the new compression...damaged a few teeth and so i had to change it out. While i was in there i replace the tail mount mount with a new ploy unit and installed a gear reduction starter to handle the new found compression.This job isn't too bad to do if you wanna save that 400.00 and put that moo la somewhere else on the car. in fact i didn't have to drop mine out of the car.I just had to remove the bellhousing bolts, the t.v. cable i unhooked from the carb.,along witht the speedo cable,pulled the trans. fill tube.Unhooked the drive shaft @ front yolk and moved to one side undone tail mount,torque convert bolts and just moved it back a few inches with wood between the floor jack and the trans. pan to get to the crank -flex bolts afterwards just walked the trans back up in place and started the first two lower bell housing bolt back. Nope not too bad at all....
Click to expand...

My only comment would be about the poly tranny mount. The poly motor mounts are fine, but the poly tranny mounts are so stiff, they tend to snap the tailpiece/mtg pads on the trannys. Just FYI, I have heard this from numerous people.
 
thanks for letting me know i have never heard bout that happening before.:eek:...i may change back to stock then....:wink:
 
big2bird said:
[My only comment would be about the poly tranny mount. The poly motor mounts are fine, but the poly tranny mounts are so stiff, they tend to snap the tailpiece/mtg pads on the trannys. Just FYI, I have heard this from numerous people.
Click to expand...


It would seem to me that it would be the other way around do to less flex, but what do I know.:smash:
 
Well Key....that's what i was thinking too that's why i install that one in the first place...instead of the soft factory one.
 
The frame can flex more than the trans/engine. So using a rubber mount will let the frame flex without putting so much stress on the trans/engine.
 
damoroso said:
Although the flex plates are interchangable, the starters are not. Also, don't go with the cheapest, go with a quality piece. You don't want to pull the trans again because you tried to save a couple bucks on a cheaper flex plate....
Click to expand...


I bought a mini-starter from the GM Performance Parts Catalog. I'm pretty sure you can use it one either diameter flexplate/flywheel.
 
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