The pin that holds the u joint to the drive shaft - how snug a fit should it be? (1915 touring)
I removed the u joint housing plugs and the pin fell out without driving it out.
Also the pin appears to have a flattened top, is this correct or should it be tapered ?
I have the John Stoltz adjustable pinion bearing setup, so I leave the pin out, and the ujoint self-centers in exactly the right spot.
The U joint pin is swaged in place - it is a rivet.
It's a straight pin/rivet that is made without a head that needs to be peened over on both ends after being inserted through the u-joint/drive shaft. That's why there are removable plugs on the top and bottom. Sounds like only one end was peened.
If yours was loose and fell out, check to see if it wore a groove in the housing. Sometimes they do if they have been loose for a long time.
Bud, on a standard T driveshaft assembly, the U joint pin needs to be riveted by peining it on both ends. The rivet needs to be tight in the hole as this stops the U joint moving on the tailshaft. Any movement here will affect the pinion gear mesh. There is a thrust face on the back of the U joint which runs on the end of the bush in the ball on the torque tube. This needs to have minimal end float to control the pinion gear mesh.
Hope this helps.
Allan from down under.
I wish they would make that pin with a head on one side, so you could rivet just one side instead of two. They made them at one time, but that was years ago.
The last pins I got from a vendor were too small @ 1/4" diameter.
Ford spec is 9/32" x 1-1/2", P/N 2574
The pinion thrust is to the front so a loose pin won't affect drive or coast thrust. On no-load occasions you might get a little chatter though.
Thanks for that spec Ken.
If there is no clearance in the pin, then the driveline will try to drive thru the pin as there is clearance in the square drive fit up. If this happens the pin will wear or shear. Since pinion thrust is always outward , I don't see why this pin is required.
The pin is needed to keep the drive shaft from moving to far back into the rear end. The u-joint rides on the upper bushing setting the amount of movement to the rear of the drive shaft.
I tap threads all the way through the joint, and drive shaft.
Then take two set screws and screw one in from each side and butt them against each other. the length of the set screws should come out flush with the out side of the joint.
What kind of set screws do you use ?
I'm guessing the type with the internal hex drive ?
Are the specially hardened ?
That's logical, Ted, but my Devin/VW diffy locked up in the glorietta of the Angel in Mexico City. I had the car hauled to a VW dealer where they found the nut holding the pinion and its cotter pin in the bottom of the case. That let the pinion gear lock into the ring gear.
They had no parts for a 1951, since they had only started assembling VW in 1956, so they put it back together for a total charge of $50, and told me it would last maybe 400 or 4,000 kilometers. By the time I got back to San Diego some 2,500 miles later, the R&P were shot, so I got a later tranny (1956?) with synchros. There were no junkyards in the interior of Mexico back then. Cars were driven forever.
I like the thread idea but if they fracture you're "screwed".
The pin is used for the other end of the thrust of the drive shaft.
With out it, that would leave the drive shaft pinion nut to ram into the carriage, and then back to the bearing thrust in the spool.
It would also leave the Joint to do the same thing. To run into the tail shaft further then in should chewing at the ball cap and with the joint having less turning surface on the drive shaft.
Bud, the set screws are allen wrench type, and they are just run of the mill type that I use.
Charlie, if that's is what it would take, I would gladly do it!