Transmission driving plate position

[Dave1]

I am in the beginning of an engine tare down for rebuilding on a 26. When unbuttoning,…removing the hogshead, it became apparent that the front of the ball cap had been touching the clutch spring support as both surfaces are scored.
This engine has been rebuilt not many miles ago, and has some other issues so this is not a huge surprise.
Wondering if anyone has a reference dimension for the driving plate position, how far should it extend in relation to the rear of the crankcase ?

Dave

[Craig Leach]

Hi Dave,
Looks like you will be replacing the 3341 spring cup and 3342 pin that is most likely the issue.
Craig.

[Mark Gregush]

If the pin is installed in the cup at rear and is seated properly in the spring and the throughout bearing is installed the correct direction with fingers in the correct slot, the spring and associated parts would be in-between the drive plate and 4th main, not touching either. Sounds like Craig is on the right track, the pin and/or cup is missing allowing the spring to ride on the 4th main.

[jiminbartow]

Exploded transmission drawings:

[Kerry]

The thrust ring that go's inside the spring cup was deleted by 1916.

[Joe Bell]

There is short and long fourth mains, if you use the early driven plates you need to use the short fourth main.

[Dave1]

Thanks, all good advice

Dave

[Jerry VanOoteghem]

Many times, the notch within the spring cup, that the retaining pin nests in, will wear, allowing the cup to sit too far back and reducing the clutch spring pressure. In extreme cases, the pin wears completely though the cup, allowing the spring to push the cup back against the spherical portion of the 4th main. You usually have no high-speed clutch engagement when that happens.

[Dave1]

Just so ya know…. Turns out for one thing the clutch disc drum was not installed far enough onto the transmission shaft.
The locking bolt on the disc drum is designed to fit into the hole in the shaft,locking the disc drum into position, in this case the locking bolt was above the hole, this allowed the disc drum to move to the rear.

Dave

[Kerry]

It's a wonder that the lip on the reverse drum against the band would let the transmission travel that far.

[speedytinc]

Just so ya know…. Turns out for one thing the clutch disc drum was not installed far enough onto the transmission shaft.
The locking bolt on the disc drum is designed to fit into the hole in the shaft,locking the disc drum into position, in this case the locking bolt was above the hole, this allowed the disc drum to move to the rear.

Dave

The set screw is more a fail safe.(if properly installed) The clutch hub is supposed to be a press fit.
Either the clutch hub and/or transmission shaft will need replacing to maintain a press fit.

[Kerry]

Using the term "Press fit" is a little exstream, that gives a mental picture of using a press, the hub only requires as Ford puts it, drive the drum down, which is no more than a firm fit.

[Jerry VanOoteghem]

Using the term "Press fit" is a little exstream, that gives a mental picture of using a press, the hub only requires as Ford puts it, drive the drum down, which is no more than a firm fit.

A hard press fit is always what I've encountered.

[speedytinc]

Some are so tight, the T Z puller barely does the job to remove & will "taco" the clutch hub.
Installing takes a good bit of hammering to get in place.