I have a 26 with a sad driving plate (loose rivets)I understand the rivets can be replaced, however a have a spare driving plate that seems healthy enough, although it is for an earlier model with the narrow style drum. The OD of the plate is larger by about .250" which could be turned on a lathe easy enough,...a bigger issue is the location of the mounting holes which, would have to be modified (elongated).
Any one attempted this modification?
I think the there would be more to this job then turning the out side to fit. I think the face that mounts to the brake drum is different. (?) Also the clutch ring is different. You could try remounting the shaft to the plate. I think you can get OS rivets from the suppliers but that may not work in all cases, depending on how worn the holes are. The rivets are not an off the shelf type, the head angle is different then the correct ones.
I am in somewhat the same boat, but my output shaft is worn and pitted but tight to the plate. I was planing on moving a good shaft over to the plate I was going to use.
Also, if your current 4th main is fitted to the one shaft it may not fit the other.
Dave: Check plates for cracks, most are cracked between the rivet holes. Like from one hole to the next. Check them GOOD. Dan
Looked at an early style plate today compared to the 26/27. Because the early style bolt hole pattern is more out board, by time you would trim it down the outer edges of the holes might ether be into the edge or very close. Also would cut into the supports for the fingers and the area inboard of the hole is not flat so that would have to be taken care of for the bolt shoulder to sit flat. Myself, I do not see that as a workable idea but a good idea in concept.
1926 driving plates are all over the place! Find one and use it. The earlier ones have a different hole pattern, and are a larger od.