Early Ford V-8 Club Forum

EFV-8 Club Forum / General Ford Discussion / Clutch "PUZZLER"

Reply to Discussion | New Discussion << previous || next >>

Posted By Discussion Topic: Clutch "PUZZLER" -- page: 1 2     MTLott 02-04-2010 @ 3:58 PM reply profile send p.m. Member Posts: 38 Joined: Oct 2009 I posted earlier asking a question about a diaphragm clutch. Spent the afternoon pulling the transmission out of a buddy's '40 coupe and thought what we found would make a "Click and Clack" style puzzler. Usually folks ask questions and the forum experts give their opinions on what the solution should be. With a "puzzler" the answer is already known. Care to take a shot at it? The situation: Swapped engines, flathead to flathead, in a '40 coupe. No change to the transmission but did install a diaphragm clutch. When ready to test drive the clutch would not release, pedal pressure was quite heavier than expected and a "metal-on-metal" sound came from the area of the throw-out bearing as soon as the pedal was depressed enough to make T.O. contact. What was the cause? Please no general guesses, be precise. (I did not have my camera but will post pictures later of not only the findings, but also of a great coupe and its new engine.) trjford8 02-04-2010 @ 6:10 PM reply profile send p.m. Senior Posts: 4219 Joined: Oct 2009 The diaphram clutch will not work with the Ford throw-out bearing. The center hole on the diaphram clutch is too small and it contacts the center part of the bearing which does not spin. This is the metal to metal sound as the pressure plate is spinning, but the bearing is not. MTLott 02-06-2010 @ 12:40 AM reply profile send p.m. Member Posts: 38 Joined: Oct 2009 Close enough. The "fingers" of the diaphragm clutch "grow" inward as it is depressed. The fingers actually grab the slightly protruding nose of the bearing carrier hub but not the center race of the bearing. This also jams the diaphragm and does not allow the clutch to release (part 2 of the puzzle). To "trj's" credit, he knew the center hole was the problem (I was a little surprized at how many locals could not be that specific.) Maybe he knows how well the diaphragm clutch would work if the hole were openned up some or the hub modified. Would appreciate that info. http://i158.photobucket.com/albums/t112/lashlarue/throwoutdisphragm.jpg supereal 02-06-2010 @ 12:08 PM reply profile send p.m. Senior Posts: 6819 Joined: Oct 2009 I have seen the diaphragm type clutch used mostly on drag cars and industrial engines, and an occasional marine application. They tend to be a "go-no go" unit that makes street use difficult. MTLott 02-06-2010 @ 2:16 PM reply profile send p.m. Member Posts: 38 Joined: Oct 2009 "I have seen the diaphragm type clutch used mostly on drag cars and industrial engines, and an occasional marine application. They tend to be a "go-no go" unit that makes street use difficult." Are we talking about two different things? What doesn't use a diaphragm clutch today straight from the factory? http://www.google.com/search?hl=en&source=hp&q=ford+oem+clutch+kit&aq=f&aqi=&oq= http://www.google.com/search?hl=en&q=chevrolet+oem+clutch+kit&btnG=Search&aq=f&aqi=&oq= http://www.google.com/search?hl=en&q=dodge+oem+clutch+kit&btnG=Search&aq=f&aqi=&oq= http://www.google.com/search?hl=en&source=hp&q=oem+clutch+kit+toyota&btnG=Google+Search&aq=f&aqi=&oq= supereal 02-06-2010 @ 3:54 PM reply profile send p.m. Senior Posts: 6819 Joined: Oct 2009 I suppose it depends on definition. Both types use a pressure plate and disk. The multi-arm "diaphragm' type depends on spring pressure to grip the disk, while the more common type seen in our old Fords uses centrifugal force to increase pressure as the speed increases. This allows less force to release the clutch in ordinary street driving. More often than not, the diaphragm clutch was lever operated, rather than by pedal, for that reason. MTLott 02-06-2010 @ 9:42 PM reply profile send p.m. Member Posts: 38 Joined: Oct 2009 First as far as definitions, the clutch originally used in our early Fords is generally referred to as a coil spring clutch. A diaphragm clutch uses a single conical spring. They are two very different designs. I really am confused by what you've written and not sure which clutch pressure plate you are referring to when you say, "This allows less force to release the clutch in ordinary street driving." It sounds like you are saying it's the coil spring with counter-weights design as found in our early Fords that takes less pedal effort. If that's what you mean, you have it backwards. You obviously have your own definition of what a diaphragm clutch is based on some isolated past experience and knowledge ... but, almost every car today uses the design, and one of the benefits is requiring lighter pedal effort to operate the clutch. supereal 02-07-2010 @ 12:25 PM reply profile send p.m. Senior Posts: 6819 Joined: Oct 2009 We see the diaphragm clutch in Ford pickups with stick shift. They are supposed to be "heavy duty", but we have already replaced two of them this year for customers, one in a one ton pickup, and the other in a four wheel drive Expedition, both used to tow a heavy trailer. Most of the clutches of any type are found in foreign vehicles, as today's automatic transmissions are better suited to severe duty, and often deliver equal or better mpg than manual. This includes the big Allisons that are becoming common in over the road applications. MTLott 02-07-2010 @ 12:44 PM reply profile send p.m. Member Posts: 38 Joined: Oct 2009 Normally when people are wrong they either admit it or simply stop posting on a thread. Worst thing someone can do is try to BS their way out of it. deuce_roadster 02-07-2010 @ 1:17 PM reply profile send p.m. Member Posts: 284 Joined: Oct 2009 What I find annoying is people who ask "questions" they already know the answer to in an attempt to show how much they think they "know". Then they argue with you when you answer. Unless you have something constructive--don't post this kind of BS.

<< previous || next >>

PAGE: 1 2

NOTE: YOU MUST BE A REGISTERED USER AND BE LOGGED IN TO POST (and reply to) messages in this forum. If you are a first time user, please click the CREATE A NEW ACCOUNT in the masthead above to register and Log In. After that, all you do is LOG IN to enjoy using this site.

DISCLAIMER: The V-8 Club does no independent testing of any of the opinions, thoughts or suggestions presented in the website on the Forum, in the Tech Tips section, or any section. A reader should consider the website to be a forum wherein differing solutions to a particular set of circumstances may be discussed. Ultimately, the selection of an item for an individual's vehicle must be based upon the independent study of the vehicle owner in consultation with people in the hobby and restoration experts.

EFV-8 Club Forum Home | Back to Home Page | Contact the Webmaster

Copyright © 2009 - EFV-8.org
Powered by < CF FORUM > v.2.1