DeMarrais Auxillary Conversion Questions

[DaveInMI]

John or anyone else:  After long contemplation, I've started cutting down the bellhousing.  I have 2 concerns so far.  Looks like he used one plate to the housing and one to the transmission bolted together-- how thick should each plate be?  Please help me with the design of the throwout bearing linkage.  Thanks in advance for your suggestions.

[ggibby]

Dave, Four inches from face of bell housing to that of the trans mission.
1/8 inch added for the centering lip on the front.
Is this what your looking for?
Regards,
George Gibby

[DaveInMI]

Thanks for the response.  I'm wondering what thickness steel to use for the plates, one welded to the the bell housing and one bolted to the tranny and then the two bolted together.  It looks like maybe 1/4" in the picture.  I don't know what thickness is required so that there is no flexing.  
   I would appreciate any solutions for clutch release bearing linkage also.

[ggibby]

Dave, your welcome.
Ah, I don't understand why you need two plates.
But as far a mounting the trans to the bell housing, the origanal used the four holes of the throwout bearing sleeve and one of the ford bell housing holes also.
Johns', set-up used all the ford holes, which will be easier if your going to use the original throwout bearing sleeve.
John used the ford bearing and bearing fork.
Just a piont, the Trasco set-up used a machined down input shaft to match the Clectrac set-up.
Trasco reused the original throwout bearing and clutch plate.
Now I don't know for sure but I think that this may have changed to one similar to the ford set up in later years, others who visit here may know better.
Any way if you have the ford shaft then you will need a ford clutch plate.
This is problably the most cost effective way just the same.
Use the thickness of plate you have, but 5/16" or 3/8" would be plenty strong.
John I believe milled his down to insure that front and back were true after welding everything together.
Best Regards,
George Gibby

[DaveInMI]

George,
  Thanks for the clutch info.  I'm open to suggestions about the plates.  The mount holes of the transmission fall directly on the the bell housing.  I put legs on an engine block and crank.  It is sitting on my bench on end so that I can balance the tranny in the pilot bearing.  It is sitting on the machined bell housing and the holes are sitting on the web of the housing.  All that is left is to machine down a distance equal to the thickness of the plate(s).  Two of the holes are on a verticle section so the holes will continue to coincide with the web.  I don't think the taper of the housing on the other two holes will change things enough to allow for machine screw heads.  Once my brain goes in a direction I am sometimes blinded to other options.  Please make any suggestions or point out my blind side.

[ggibby]

Dave, What other information do you have to reference the during the building of your set up?
The HPOCA club magizine had a pretty good article on this subject.
This has also been covered quite throughly in this dicussion page at earlier times, you should be able to search right to it.
Now, based on what you have written about already, I would think the next step is what you suggest.
Machine down to allow for the thickness of the plate you plan to use.
Keep in mind you will probably want to machine the new mounting face once final welding of the plate has been acomplisted and to account for warping.
This would be per John D. instructions.
After machining and tacking the plate in place for trail fit.
It seems then you could machine away the bits of original housing to give you a flat place for a nut or bolt head.
Once you have all the other dimentions set and final welding of the plate acomplisted you could dress up or close these holes by welding fill in pieces and grind things to your liking for a finished look.
I you keep thinking ahead you should ahve good results.
Regards,
George Gibby

[DaveInMI]

I have the HPOCA article, Trasco info sheet, and pictures from this site.  I have done a search on this site and read what I could find.  I have some foggy memories or reading more than I was able to find in the search.  Thanks for your help.  I'll report on the results when I get there.

[ggibby]

Dave, Looking forward to it.
Good Luck,
Regards,
George Gibby

[jdemaris]

J. de Marrais here.  I'll be glad to answer any questions about fabricating the aux. trans. setup for the HG or OC3.  My usual domain email has been down and I've been to cheap to put it back up. My backup email address is: mailto:jdemaris@capital.net">jdemaris@capital.net
  I also got an original Trasco aux. setup here all apart with digital photos if someone wants/needs them.

[jdemaris]

Question to me from Dave:
"Thanks for the response and offer for more information.  What thickness plate did you use?  I'm thinking one bolted to the tranny and the other welded to the housing and then bolt them together.  Am I on the right track?  How did you mount the clutch release linkage?  I have both Ford and Cletrac parts.  Is the flat section of the bell housing mounted up or down?  ...........Dave"

My reply: The plate I bolted to the Model A transmission is 1/2" thick.  I think using the plate is necessary for a number or reasons. It provides a place to bolt the fuel tank mount to.  Also, the four bolts that are used in mounting the Model A transmission, when used originally in the Ford car, come through the inside the bellhousing.  So, the transmission cannot be removed by itself since these mounting bolts cannot be accessed unless the engine is out.  I wanted the transmission to be easily removable, so with the adapter plate, it is bolted to the trans with the bolts pointing towards the trans, and then,  four bolts pointing the other direction mount it to the modified bell housing.  This way, you can access and/or remove four bolts at any time and easily remove the trans. (with plate still attached to it).
 The plate I welded to the bell housing was 3/8" steel plate, but it tends to warp slightly when welded.  So, once welded and cooled, the assembly was finished milled - in order to make sure the plate was smooth and also to insure that its surface was perfectly parallel to the engine mounting end of the bell housing.
  I've attached a  couple of image files.  I have a full series of digital photos and drawings.  Since I've been asked so many times about this, I think I'm going to try to get Blake to put up a separate directory on his Cletrac site with ongoing discussion and a full set of photos.
  Originally, I was selling what I had for $15 to anybody who wanted my info.  I had been planning to put together a small book on how to construct the aux. trans. setup.  But, I don't think I'm ever going to get around to it.  So . . . it might be better just to post my photos and notes and invite other input.  I'm sure my work can be improved upon.  I do think, though, that my setup is better than the original Trasco for a number of reason, e.g. my transmission can be easily removed in a couple of minutes, my driveshaft uses original Cletrac u-joints (Spicer) and comes apart and comes out sideways, I don't modify the original Ford transmission input shaft, and my setup uses a readily available and relatively cheap Ford clutch disk.
 In regard to the article that appeared in the Oliver collectors magazine.  As I recall, it was NOT very informative, lacked a lot of details, and the person in the article paid to have it done - i.e. did not do it himself.
  You asked about the flat section of bellhousing.  I mounted the housing facing the same way as original. Some have an access door on top, and some don't.  I used one with the access door, it works better for several reasons.
  For now, I'll try to answer specific questions and send you relevant images.  Too much to send all at once.
As far as the clutch linkage goes, I've got photos and diagrams.  I designed it to have exactly the same leverage as the original linkage, so clutch pedal travel and pressure remains the same.
 I'm going to post a copy of our correspondence on the Cletrac forum in case anybody else wants the info.
 
John de Marrais

[ggibby]

John, Hello.
The plate is a good idea, I missed the this in the information you had sent me some time ago.
$15.00 seems like a reasonable price for what no doubt represents many hours of careful work.
The setting up of the clutch in my mind may be hardest to get right if you have no point of reference.
Keep well all.
Regards,
George Gibby

[jdemaris]

Photo of modified Ford Model A 3 speed trans mounted on modified clutch housing, modified/fabricated driveshaft, and modified fuel tank mount.

J. de Marrais

[jdemaris]

Photo of modified Ford 3 speed trans. and modified Cletrac parts installed.

J. de Marrais

[jdemaris]

Original image not mine; I digitally installed the Ford aux. trans. to show how it all fits.  It's much easier to do digitally than in real life.

John de Marrais