Thread: Breaking Lugs

Tweet

1968 C-10 1/2 ton Chevy pick up truck. 6 lugs. 7/16". This truck has big wide Rally wheels on it. Had the tuck about 3 years. It,s always brakeing the front lug nuts. All on them. I guess the big wide wheels and tires just put to much pressure on them. Not the stock wheels ofcourse. What I,m going to do. Is put some 1/2" lugs on the Wheel thing.( don,t know what it,s called.) What I would like to know is. What size should drilled the holes out to put the 1/2" Lugs in?

Breaking lug studs indicates that something serious is going on. Are the wheels made for the Chevy 7/16" studs? Do not use 1/2" hole wheels on a vehicle with 7/16" studs. Is someone overtightening the lug nuts ..... OR severely undertightening them? Find the specification for your truck and use that torque. Retorque the lug nuts after a day. Check them periodically to see if they are loosening.

How many times has this happened? Did all of the studs break the same time? If each stud location has broken only once, could someone have overtightened the studs at some time in the truck's life?

Putting larger diameter studs is tough if the wheels are drilled for 7/16" dia studs. Also, there are quite a few stud models....each has a knurl diameter that is pressed into the hub. The diameter of the knurl determines the diameter of the hole....the knurl dia is larger than the hub hole diameter so there is some metal deformation when the stud is pressed in. You have to match the knurl length to the thickness of the hub, etc. I dont think that going to 1/2" studs is the answer...it is a band aid and does not fix the root problem.

mike in tucson

Mike, Thank you very much for your reply. The history of the truck is this. I bought the truck about 3 years ago. The big rally wheels and tires were on the truck. Not long after I had the truck. One of the front lugs broke. So I replace it with a new lug. About a week later. Another lug broke on the other front wheel. I replace it. Every so often after that one or two lugs would brake. After a while I had replaced every lug on both front wheels. 12 lugs in all. And I would say per haps over the last two years I,ve replaced about 25 lugs. They would at first only brake one or two at a time. But now they all will brake. The truck has the old drum type brake drums. I inten to replace them with a calbier type wheel. So the 1/2 lugs are intened to be a temperary fix. Do they make lugs that would not brake? The ones I have been buying are stock lugs from Auto Zone. Perhaps that is why they are braking. LOL.

And by the way. The holes on the wheels do look like thier made for a 1/2" lug.

If the holes are too big the nuts will bottom out against the drum and not hold the wheel tightly. The result is the wheel working and breaking the studs.

John,

The lug studs sold at AutoZone, PEP Boys, etc are usually Dorman brand, the standard of the industry. Lug stud quality is not the problem. Are you buying the correct stud? Just because the thread is the same DOES NOT mean that the stud is correct. The diameter and length of the knurl is also very important.

Did you measure the hole in the wheels....see REM's message above.

Mike and Rem, Thank you very much for talking to me about this issue. I think Rem made have hit the nail on the head. I,ll bet that is what,s happing. Now I think I did hold a nut in the wheel at one time to make sure they were not bottoming out. Not real sure if I did that or not. But I know I did,nt check to see if the untreaded part of the stud was sticking out to far. Could,nt check it out today. Thier was some strange cold white stuff comming from the sky. I live in mid Georgia. And we don,t get that kind of thing around here.LOL.

My son had a 68 with 6 lugs and wide tires with aluminum wheels the studs were breaking off he finaly ask me why. Untill then I didn't know he had a problem. With the aluminum wheels being so wide at the center Where the studs go through) and him using the lugnuts that you cant see the threads when there on he couldn't see he wasn't getting but about 1/2 the stud. We put on the right studs (about 3/4" longer) and every thing was fine.

Been looking into getting some raceing wheel studs from Summit Racing Parts. I wounld think they are a lot stronger than the stock type wheel studs. But don,t really know. I read about some they sell there that say they are rated at 195,000 psi shear strength. Sounds like nothing could be that strong. LOL.

John,

Advice is to find the problem and fix that....not to put bigger/stronger studs on it.....you're only putting a band aid on the problem. Find the problem and fix it. Trucks breaking lug studs is not normal.

Mike, Thank you for taking the time to discuss this issue with me. I have checked the front end and sterring. Seems to be tight. I,ve also thought about the lug nuts. As far as I can find . there are only two angles for lug nuts. 60 degrees. Which seems to be the standard. And 45 degrees. Which seems to be an odd ball angle. I bought a stock wheel stud and stock lug nut. From Auto Zone. Doman brand stud. But the lug nut was made in tiwan. But it,s looks like 60 degrees. Have,nt check it yet with a potractor. I,m going to saw the nut in half. Put it inside the hole on the wheel. and see if it is soilded up against the angle in the hole. I,m thinking that the proplem is the wheels. Or perhaps the lug nuts. The stock wheels for that truck are skinny. The one that are on it are real wide. I think thats where my issues are. Thanks again for your advice.

ok, exactly how big are your front tires????

I think they are 15X8. The big rally type wheels with 6 lugs. The stock wheel studs are 7/16X20.