Sunnyjay Posted April 25 Share Posted April 25 Hey Friends, The torque arm on my 1925 Packard 243 has snapped. In preparing to weld it back together, I noticed that to align the crack, makes the pin no line up. To correctly line up the pin, the crack has a significant gap. Any suggestions? Also, will this alignment impact the pinion angle on the two universal joints on the prop shaft and if so, what is the correct angle? Thanks! 1 Link to comment Share on other sites More sharing options...
edinmass Posted April 25 Share Posted April 25 Welding that is NOT a good idea. Too much load and shock.........and cast iron is brittle at best, and the repair will never be strong enough........I would find a used one, or make one from modern steel using a water jet. I'm a purist......and finding a used one won't be easy. With some effort you can make one up that looks very similar. 2 Link to comment Share on other sites More sharing options...
human-potato_hybrid Posted April 25 Share Posted April 25 If you know the part number on that, get in touch with the Studebaker Museum and Bruce Blevins. I can get you contact info. These guys have all the surviving factory drawings. 1 Link to comment Share on other sites More sharing options...
Lee H Posted April 25 Share Posted April 25 If you do weld it, and even if you don’t, I might recommend re-figuring the proper pinion angle. Springs sag, mounts settle, and the spec angle may no longer be ideal. This calculator is from Spicer, and if you plug in the current output shaft and driveshaft angles, you can then play around with the pinion angle that will minimize the 2 u-joint angles (best <2*). https://spicerparts.com/calculators/driveline-operating-angle-calculator#more 2 Link to comment Share on other sites More sharing options...
Bloo Posted April 25 Share Posted April 25 (edited) On a 2 u-joint driveshaft the angles should be equal and opposite for vibration free operation. Equal and additive might also work, but I wouldn't expect to see that in a prewar car. In some cars the angle is fudged a little bit to deal with spring windup or load, but if that torque arm on your Packard ties things together in such a way that the angles never change, the two angles should probably be exactly the same. What should the angles be then? If the u-joints are greased with roller bearings or something similar in them, around 2 degrees at both ends would be good. Joints with plain bearings and a constant oil supply are sometimes run dead straight. Knowing this, I think you can figure out how it was before it broke. My suspicion is that the remaining section bent after the first section broke, explaining the gap. Edited April 25 by Bloo (see edit history) 1 Link to comment Share on other sites More sharing options...
DFeeney Posted April 25 Share Posted April 25 I would post on the Packard page. As popular as these cars are someone must know of a spare part. 1 Link to comment Share on other sites More sharing options...
Sunnyjay Posted April 25 Author Share Posted April 25 3 hours ago, human-potato_hybrid said: If you know the part number on that, get in touch with the Studebaker Museum and Bruce Blevins. I can get you contact info. These guys have all the surviving factory drawings. Bruce is already checking for me. I hope he has them! 1 Link to comment Share on other sites More sharing options...
Sunnyjay Posted April 25 Author Share Posted April 25 2 hours ago, Bloo said: On a 2 u-joint driveshaft the angles should be equal and opposite for vibration free operation. Equal and additive might also work, but I wouldn't expect to see that in a prewar car. In some cars the angle is fudged a little bit to deal with spring windup or load, but if that torque arm on your Packard ties things together in such a way that the angles never change, the two angles should probably be exactly the same. What should the angles be then? If the u-joints are greased with roller bearings or something similar in them, around 2 degrees at both ends would be good. Joints with plain bearings and a constant oil supply are sometimes run dead straight. Knowing this, I think you can figure out how it was before it broke. My suspicion is that the remaining section bent after the first section broke, explaining the gap. That is very helpful @Bloo. Thank you so much! I agree, I think the rear axle must have hit something major, to brake the arm and crush and break off the bijur lines on the driver's side. From there a bend in the intact arm seems very possible. Thanks for your help! 1 Link to comment Share on other sites More sharing options...
Sunnyjay Posted April 25 Author Share Posted April 25 3 hours ago, Lee H said: If you do weld it, and even if you don’t, I might recommend re-figuring the proper pinion angle. Springs sag, mounts settle, and the spec angle may no longer be ideal. This calculator is from Spicer, and if you plug in the current output shaft and driveshaft angles, you can then play around with the pinion angle that will minimize the 2 u-joint angles (best <2*). https://spicerparts.com/calculators/driveline-operating-angle-calculator#more Great resource. Thanks so much! 1 Link to comment Share on other sites More sharing options...
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