Advice Needed: front lug thread engagement

[95050JohnR]

Finally got around to checking the fitment of the rims after the brakes were installed and have a question regarding the minimum lug thread engagement. As seen in the photo (hopefully it attaches correctly), you can see the lug is nearly flush with the stud, but 1/4" of the tip of the stud is non-threaded which results in the lug not fully engaging 100% of its threads. I'm not sure if this is safe or not.

Here's my setup:
17" Halibrand FFR 9" front wheels
Wilwood brakes from Gordon Levy which uses a .090 spacer for caliper/rim clearance

In full discloser, I spoke to Gordon regarding this, and he was very helpful in suggesting I ensure the hats are FULLY seated against the hub. I'm pretty sure I opened the lug holes in the hats to 9/16" to clear the protruding shoulder of the stud but I'll double check. Assuming everything is seated correctly, do I need to install longer studs? If so, can that be done with the hubs installed (not looking forward to going backwards and especially re-torquing the hubs).

Thanks in advance,
John

216657

[gbranham]

I was always told that minimum "safe" engagement is the number of threads equal to the diameter of the lug. So if its, say a 3/8" diameter lug, you need the number of threads that equal 3/8" of lug length.

[narly1]

A new set of longer studs costs about $20 and about one evening of your time to change them out.

Cheap insurance IMO.

I'm in the middle of doing it myself right now. Consider Dorman 610-395 They are the same length as the stockers but threaded all the way out to the end.

Earl

[rich grsc]

If you have 1/2" of thread, thats fine for a 1/2" stud

[CraigS]

That may be at the minimum. We can't be sure since we can't see how deep the nut is but I'd be looking for the ones narly1 listed above.

[95050JohnR]

Thanks all. A quick calculation and it appears I have a little over 1/2" of thread engagement (~600 mils from what I can glean). Full thread depth of the lug is ~700 mils. I'll probably stew over this for a while before deciding what to do. Can the studs be swapped with the hubs installed?

[gbranham]

Thanks all. A quick calculation and it appears I have a little over 1/2" of thread engagement (~600 mils from what I can glean). Full thread depth of the lug is ~700 mils. I'll probably stew over this for a while before deciding what to do. Can the studs be swapped with the hubs installed?

Nothing to stew over; you're fine.

Greg

[narly1]

Can the studs be swapped with the hubs installed?

The preferred technique is to pull the hubs off, press out the old studs, and then press in the new ones.

Earl

[CraigS]

I removed mine w/ a big hammer. Installed the new ones w/ a nut run on backwards against a couple of hardened washers all well covered w/ bearing grease. Grease the threads too.

[narly1]

The preferred technique is to pull the hubs off, press out the old studs, and then press in the new ones.

Earl

I have a small shop press but you could probably get by using a bench vise if the jaws open far enough. I use a deep hex socket to support the hub flange and let the stud drop down into that.

Earl

[phileas_fogg]

Like Craig, I used a ball peen hammer (tap tap tap tap) and kept the hubs installed. Surprisingly easy to do.

Again like Craig, I used a couple of washers & a lug nut run on backwards. Grease makes this easy. Go slow at first to make sure the stud is being pulled in square to the hub.


John