Brought to you in part by:


Tools & Supplies by Eastwood

  Mustangsandmore Forums
  Technical Brainteasers
  Crack in C-4 flexplate

Post New Topic  Post A Reply
profile | register | preferences | faq | search

UBBFriend: Email This Page to Someone! next newest topic | next oldest topic
Author Topic:   Crack in C-4 flexplate

Posts: 8
From: Green Bay, WI
Registered: Nov 2001

posted 12-06-2001 08:36 PM     Click Here to See the Profile for punk6     Edit/Delete Message   Reply w/Quote
A while I read a post where a guy said he routinely puts a new flexplate in a car before replacing the tranny (assuming that the 30+ year old one has not been replaced previously). Anyway, the thought was they all crack anyway, so it's cheap insurance, and you don't have to pull the tranny later. I looked at the plate out of my 72 Mav (250 six) and sure enough, it's cracked (on the starter gear in the valley between 2 teeth). I don't remember if the flexplate normally cracks along the gear or where it bolts to the crank. Is one crack in the starter "fatal"? Thanks guys.

IP: Logged


Posts: 18560
From: Saco, Maine MCA # 47773
Registered: May 99

posted 12-06-2001 09:16 PM     Click Here to See the Profile for SteveLaRiviere   Click Here to Email SteveLaRiviere     Edit/Delete Message   Reply w/Quote
Yes, it is. A crack means a failure will happen soon, and after you get it all together do you really want to take it all apart again a little while later?

'70 Mustang Mach 1 M code 351C 4V/FMX/3.25 open
'72 Mustang Sprint Coupe 351C 4V/FMX/4.30 Trac Lok
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip
'97 Probe GTS 2.5L DOHC
My Photo Page
Christmas shopping? Why not use the Bookstore?

IP: Logged


Posts: 718
From: Demopolis AL
Registered: Jun 99

posted 12-15-2001 04:23 AM     Click Here to See the Profile for 74merc   Click Here to Email 74merc     Edit/Delete Message   Reply w/Quote
worse case scenario, I've seen brand X's with broken flexplates driven for years.
it causes driveline vibration, a great deal of it in the engine.
I replaced the flexplate, still knocked.
me an' bossman had a nice fight over whether I knew how to put on a flexplate and whether I tightened it down tight enough...
so, moral of the story, the guy drove the truck for a year or two with it knocking, I think the flexplate allowed vibration to get to his reciprocating assembly and hose his engine.
or it could be the other way around, rod knocking for years eventually find a weak spot in the flexplate...

IP: Logged

All times are ET (US)

next newest topic | next oldest topic

Administrative Options: Close Topic | Archive/Move | Delete Topic
Post New Topic  Post A Reply
Hop to:

Contact Us | Mustangsandmore Front Page

Copyright 2001, Steve LaRiviere

Ultimate Bulletin Board 5.47d

Amazon Honor System Click Here to Pay Learn More

[About M&M][Acronym Guide][Calendar of Events][Chat Room][Classified Ads] [Links]

[Members' Photos] [Restoration Info][Tech Tips] [ Technical Articles][Ford Technical Data

[ Bookstore] [Advertise on] [ T-Shirts]