What size / length of knurl should my '72's rear wheel studs be? Research I've done indicates the early applications require a .580 knurl, with "late model" being a .486 knurl.

I'm having 2 problems. My son's Torque Thrust 2's keep loosening up on their own and I've had a couple of studs back out of the axle flange and now I can't get the loose lug nuts off. Not only is this dangerous when it happens, it's a major PITA to fix. (the "son, you need to keep your eye on this stuff" issue is another story for another thread) I'm going to have to pull the axles this time to replace.

This happened once before and I'm afraid the generic crap I've bought at O'Reilly was the .486 ish knurl (and only a 1/4" deep) even though they were given the application. It was definitely press fit but probably not the right size. It's my fault for not verifying what I was given.... I know better after dealing with them for all these years.

I'm a dumbass. With that established and out of the way, I want to make sure once and for all what I should get before I pull all this apart.

Any ideas why they keep loosening? They are acorn and we retighten after the inital drive and it keeps happening. I wonder if the incorrect studs is allowing it to rock enough to loosen the nut? It's not happening on the front wheels at all and it seems to be this same wheel.

I remember them coming loose when we first got the wheels and that reminded us of the re-torque obligation of an aluminum wheel. I'm afraid we replaced the busted stud at that time with the el cheapo and the vicious cycle starts. The wheel doesn't look wallowed out or anything.

Help! o gurus and knowers of all...

I usually use the 186 studs. These are a little longer than stock, so they might not work with the nuts that you are using. Be sure that the stud bottoms out when you press it in the axle. Some people don't get them seated all the way.

Gently knock one out using a brass punch or a heavy piece of aluminum rod stock and take it to NAPA or onna the other older, bigger parts places and ask if you can look though their great big drawer full of studs and pick out what you want.

Otherwise, knock them all out and have a competent Machine Shop install 1/2" Grade-8, althread type bolts and long Allen Set Screws in the length you want...

I did... Had Mosers do all of mine and used their stuff too...

pdq67