I have a '26/27 transmission. The drive plate to tailshaft rivets are quite loose. First question: Do any vendors sell rebuilt or new drive plate/tailshaft assemblies? I checked a few of the usual vendors without luck. 2nd question: Assuming I will have to repair/install new rivets in my existing drive assembly, what vendor does this type of work? I assume I will need oversize rivets (available from Snyders). Thank you for any advice you can offer.
I had to replace mine a while back and found nobody making new ones. I did find a used one through Bobs Antique and Langs also has a fairly large used part selection. You have to call them though as used parts aren't in their catalogs.
Not that I recommended it but you can stick a mig welder in the hogs head opening and weld the rivets(temp fix). Had to do that before an endurance run about 20 years ago. Obviously replacing is the best way to go.
I rebuilt the engine and trans in my '26 this past spring. While the driven plate was out at another T owner's Tony Traut's shop he noticed the loose rivets. He turned new rivets on a small lathe, drilled out the holes and hammered them in. The problem was solved.
Gene, these are the rivets you need.
A problem not addressed is that when the rivets become loose, the holes in the driving plate and perhaps the gear shoulder become oblong. They can be repaired by redrilling, countersinking and using OS rivets, but alignment is hard to maintain. I'd search for another driving plate.
Check it GOOD for cracks. I am finding a lot of them cracked. That is reason for the loose rivets. Dan
The most likely reason for cracks and loose rivets in the drive plate is misalignment of the "fourth main"/ball cap. This causes the shaft to flex where it is riveted to the plate.
This misalignment can happen over time (such as bending of the crankcase) or due to not properly aligning the cap during an overhaul or rebuild.
I have an NOS 26-27 drive plate and matching brake drum for sale if anybody is interested.
Gene, unless the rivets have been loose for a long time, and the holes in either component are obviously ovalled out, simply re-rivetting the plate will fix the problem. I would remove the old rivets one at a time, re-fitting a new rivet as each one is removed.
Hot rivetting will expand the rivet to fill the void into which it is fitted, thus compensating for some wear in the holes. Once one is done, I would do the one opposite that, until all are done.
Oversize rivets may be better, if they will go in the holes.
Hope this helps.
Allan from down under.
I may still have some 26 clutch plates. If you are interested let me know and I will look through them.
If you re-rivet your plate, be sure to check it afterwards for run-out between the flange face & the flange diameter, to the shaft center line.
Erik, do you still have that drive plate and drum? if so I am interested in them. please PM me.
Another way you could go and what I would do is put one end of the rivet on a flat spot and PEEN the other end with a sharp center punch a few times then smooth out the raised spots. If your holes are not wallowed out too much, I would think that your clutch plate would be as tight as brand new???
My experience has been that trying to tighten up the old rivets is a lost cause. I had to do it when I was young and on a tight budget. Always found the rivets eventually loosened up. I like Allan's approach and then Jerry's suggestion of checking runout.