I have broken my second set of 1/2" rear axle studs on our 11 second Nova.
355 SBC 400 TH with internal brake.
9"X28 drag radial at 21psi.
The first set of studs were the studs that cam with the axles. All 5 broke together on the right rear. I replaced all the studs with the higher priced ARP studs.
Broke one of the ARP studs last weekend.
I called Weld Wheels last week to ask about the proper shank length of the lug nut into the wheel. The shank length is 1.38" and the thickness of the wheel is almost 1.5". That leaves .12" of stud that is unsupported.
My question to Weld was what in there opinion could cause this. Tech guy said he would ask engineering but have let to get a reply back.
I'm asking the DRR tech line here if they have any positive suggestions that may shed some light as to what I can do to remedy this situation.
Car has a 1.60 60ft time. Years ago I ran low tens on 1/2" studs 14/32 slick and a clutch.

Both sides? What you torqing them down to?

You sure the lugs are fitting tight to the holes and there isn't slop? Diameter wise? You don't want the shank to bottom out.

I would put your lugs in the hole on wheels. I'd there is slop discreet diameter wise your prob beating them to death. They should fit nice and you shouldn't be able to wobble them around. One like that now you have 4, one more and you have 3. My guess is they are hogged out.

No way they should be breaking at that power level.

quote:

Originally posted by ski_dwn_it:
Both sides? What you torqing them down to?

No way they should be breaking at that power level.

I agree on the breakage. Studs have only broken on the right rear.
All lugs are the 1.38" as recommended by Weld.
I torque to 100 lbs.
Weld says 90-100 is there spec. Lugs fit tightly in the bores.

Always run same wheel on that side? Move it to other side and see if it follows. If nothing is obvious.. If it follows the issue is with the wheel

Try different torque wrench or test it against another. Use different torque wrench go to 90, see if the original cranks them on further.

Check the run out on you axel flange.

I have the same studs and Weld wheels, you didn't say which ones. I had this problem 10-15 years ago and it turned out to be the wheels were compressing + were worn where the lugs tightened on the outside thus the lugs were bottoming out. I milled 1/8 off the lugs and still have them on the car today with no more breakage. Big Olds that 60s in the low to mid 1.30s with 14in tires. And torqued 100lbs with a tested wrench.

Though I would think 1/2" studs should be fine in your application Bruce, they do make 5/8" studs for a reason......

What Weld Wheels?

Prostar and drag lights have a floating center support that will compress?

Do you have a washer between the lug nut and wheel?

Are these open ended lug nuts?

Weld drag lights with the floating center.
I did more investigation and I believe that the lugs may be bottoming out.
I previously measured the thickness of the center with the wheel off the car. This time I measured with the wheel torqued and measuring through the whole with the broken stud. Quite a bit of difference between the torqued thickness and non torqued.
Thanks for all of your input.

Dave 5/8" studs will be the last resort.

quote:

Originally posted by Bruce Williams:
Weld drag lights with the floating center.
I did more investigation and I believe that the lugs may be bottoming out.
I previously measured the thickness of the center with the wheel off the car. This time I measured with the wheel torqued and measuring through the whole with the broken stud. Quite a bit of difference between the torqued thickness and non torqued.
Thanks for all of your input.

Dave 5/8" studs will be the last resort.

The good thing about 5/8" studs in your situation Bruce is it does away with lug shanks as the wheel now locates on the unthreaded part of the 5/8" stud....the nut and washer now clamp on the outside face of the wheel eliminating any chance of not compressing the wheel properly....And they're stronger lol