TR5/TR250 Wiper wheel box knurled end not tight on arm

The windshield wiper arm on my TR250 does not fit very tight on the knurled end of the shaft on the reproduction wheel boxes. I saw a forum entry from 2015 where JerryVV said he, and other TR250 owners, had the same problem with the reproduction wheel boxes. This is causing the wheel box shaft knurled end to turn inside the wiper arm. The knurled end also seems as though it was made out of a very soft aluminum thus it seems to have worn down even more than when new. Is there anyway to replace the knurled end of the shaft with a knurled steel piece instead of aluminum? Any idea where I would get steel ones. Thanks!
Bob

Bob, wrap the end with a couple of loops of aluminum foil, leave some overhang on the top so when you push it down it will not just shove off.
Hope you don't have to drive too much in the rain, surely it will stop soon, it's been a unusual last few months.
Certainly not a permanent solution but should work so they don't go flying across the hood. That would be putting the old ones back in. Now that was easier said than done.

You could drill and tap a hole for a 'grub screw' to hold the arm onto the splines.

I like the idea of "both". Since the wiper arms, wheel box splines, and wheel box nuts all seem to rust permanently together, I would also use anti-seize on the assembly. It will be messy going together but very helpful later. I also suggest that any set screw be stainless... and coated with anti-seize.

Thank you for the responses! The grub screw and aluminum foil solution would work. The wiper arm is a bit thin to thread for a grub screw so that may be a problem. A question... would it work to put a thin layer of JB Weld on the knurled end of the shaft and then file it down to the "right" size? Would it stay on, or would it peel off? Thanks!

p.s. I was hoping for solution that would not be visible, hold up for a long time, and not involve replacing the wheel boxes.
Bob

Would a layer of black tape or cloth work as a quick fix? I got a better idea. Don't drive in the rain. My TR6 wipers work fine -but they have never been in the rain in 23 years.

You don't thread the wiper arm..it's just a hole for the machine screw.

JB Weld will not work to build up the splines. As you suggested, if the arm can turn on the splines, the JB Weld will shear off. If the arms just wiggle, the JB Weld will get pulverized into dust and fall out.

Thanks Doug! I agree that JB Weld would not stay on. Just a shot in the dark!
If I have to hold the wiper arms on with a screw, I was thinking I would use a short set screw that uses an allen head tool inserted into the end. That way there would be hardly any head showing up outside the wiper arm. I don't know if there is a set screw with the right type of thread to screw into the wiper arm without having some threads.
Bob

Just my two cents ... on my Connecticut to California and back drive (1960 Mercedes-Benz) a few years ago, the first time I hit rain (Minnesota), my wipers stopped wiping. Both arms were slipping on the drive shafts.

So I got some heavy-duty aluminum foil from a local diner, pinched two layers (about one inch square) around the shafts, pressed the arms back on ... and the wipers worked fine for the rest of the trip (another 3000 miles). The arms didn't use screws - just pressed down on the shafts.

Tom M.