I am currently assembling a 1915 transmission that has a distance plate, 13 small and 13 large
disks. Starting with a large disk on the distance plate and alternating the small and large disks you end on top with a small disk. Later years they discontinued with the distance plate and changed the disk arrangement to 13 large and 12 small disks. With the later disk arrangement you end up with a large disk on top. In the later transmission information they are very specific not to have a small disk on top. When I completed the 15 transmission it ends up with a small disk on top. What is the difference between an early unit with a small disk on top and a later unit with a large disk on top?
Do not finish with a small plate in contact with the pressure ring- it will wear out the pin holes in the driven plate in short order.
When you say "pressure ring" do you mean "clutch push ring"? What is the "driven plate"? The only contact the top small disk has is with the "clutch disk drum". I am very much interested in your comment but I want to be sure of the specific parts. In the early parts books 13 small and 13 large disks are required plus a distance plate. However in the early parts books they are not specific as to what disk to start with, only in the later directions (mid 16 and later) they mention to start with a large disk and therefore end up with a large disk where 13 large disks and 12 small disks were used. On the 15 model 13 of each were used therefore should I start with a small disk to end up with a large disk on top? If I go with the 12 and 13 configuration then I would need an additional spacer to make up the difference. How therefore should I configure the 13 small and 13 large disks?
Think about it. The small discs rotate with the disc drum, the large with the brake drum. Since the driving plate with the holes for the push ring is attached to the brake drum, you want push ring pins to contact a clutch disc that is not moving. If they contact a small disc first, the movement will cause sideways pressure on the pins and the holes in the driving plate will become enlarged over time.
Three of my driven plates are like this:
The holes for the push ring pins are elongated - likely since someone assembled the clutch pack in the wrong order sometime in the past.. With a small disc in the end towards the push ring, some of the power goes via the pins through the edges of the holes instead of through the large discs and the lugs in the brake drum.
Should the holes be allowed to grow too wide, there's a risk the push ring pins slides to the side of the clutch arms and then the clutch will slip.
Brass them up, and dill again.
The clutch assembly is starting to make sense I can understand the reason for the large disk on top, therefore for the 13 and 13 configuration on the early assembly a small disk will have to be placed on the bottom firstly alternating to a large disk on top. An additional question about the distance plate I was informed it goes on the bottom first, In reviewing some early exploded views of the Ford transmissions the distance plate appears to be in the middle of all the disks?
Looking a the three major parts dealers catalogs they all show the same clutch disk configurations for 09 - 27 with 13 large disks and 12 small disks, where as the 15 and part of 16 models had 13 of each and that is not mentioned. They also display the hex style large disk in lieu of the round style. The round style large disk and the hex style are not enterchangeable however they are all listed for 09 - 27?
You can use the hex style large disc on all years, but the round style can only be used in 09-25 narrow brake drums. When the improved wider drums got lug shoes to protect the lugs from wear, the holes for the fastening screws had to be moved to new lugs in between - the hex style is for clearing the new lugs for the fasteners.
David, Before you place the thick spacer plate,look at where the clutch drum rides in relation to the discs.It should go in first to fill the opening at the front of clutch disc area.The small discs could/can slip down and jam the tranny . Do not try to use the three washers in there also. HTH.
So if I am reading this correct, the early brake/clutch drum assemblies used a different total height of the clutch disk stack. I thought all transmissions used a total height of 1 1/8 inches for the stack and that the thick disk placed at the bottom took the place of 2 large 1 small disk. The thick disk I have look to be 3 large disk bound together.
I understand the three washers were to be installed in place of the flanged bushing. I placed the driven gear in the flywheel over the transmission shaft to check for clearance prior to assembly and with out any washers the gear will rub on the flywheel. One washer appears to offer sufficient clearance and three washers appears to be excessive. There is trace evidence of the gear having been rubbing on the flywheel prior therto even with the flanged bushing. Because the flanged bushings are no longer available the washer(s) are used in lieu. To use no washers may cause some unwanted friction and to use the recommended three washers appears to be excessive. I appreciate all the assistance on this project. The transmission is still on the bench with the small disk on the top of the arrangement however I will disassemble it (again) and reconfigure the disk arrangement. All the clearances are perfect and it moves with no binding. I have read all the information I could find on the subject and there are many silent areas in the texts. The later and early information appear to run together and in some cases becomes unclear.
A further point, it was learned from an earlier poster that the distance plate was discontinued in mid 16 along with one small disk. With these two components removed there is a space of .160 created, were the housings redesigned to make up the difference or was the difference gained in the finger adjustment? There is sufficient adjustment however it places the finger adjustment at its limits.
The brake drum bushing with the flange was eliminated and replaced with the conventional one which now required the 3 steel thrust washers - note that there was a change in the clutch drum that coincided with the removal of the flanged bushing.
If you have a transmission with the flange bushing, and want to use the 3 washers, all you have to do is take .015 thousandths off the washer side of part No. 3332 which is the transmission clutch disk drum.