Shearing off wheel studs on s60

[firebird_1995]

So last night me and my dad took his car to the local 1/8 mile track to do some tuning. He's driving, I'm watching in the stands. First pass, tons of wheel spin, nothing impressive. Second pass, car rises up good out of the hole then gets crazy squirrely. I'm thinking to myself, "Jesus dad let off the throttle", well what happened was the passenger side wheel had come off! They got him off the track and when I got there I seen all 5 studs had sheared off. We started working on getting something temporary to get it back on the trailer and he tells me BOTH sides had sheared off the week before. This was on 10x17 zr1 rims with mickey thompson street comps, stock style acorn lugs, no spacers. Rear end is a strange s60 with a spool. Strange brand screw in studs both times. He chocked the first time up to the possibility of the lugs being loose, but the second time there was no way they were loose. He had just checked them the run before. So I don't think they were loose the first time either. I did some searching and came up with SEVERAL people that had the same thing happen. The common denominator being stock style wheels and lug nuts. Some had mentioned that strange/moser recommends shank style lugs. That makes sense because while running his prostars with shanked lugs he didn't have this problem, only with the stock rims/lugs. The issue I have with this is, how is it guys can run 1.5-1.4 60' on stock rear ends without shearing the studs but the "stronger" aftermarket rears with their brand studs cannot without the use of shanked lug nuts? Seems to me the fastener quality is to blame. Anyone had this happen or have any input?

[Chris]

Really? I57 was hooking that well lol

Thats nuts!

[firebird_1995]

He was running street tires so I doubt he was hooking that hard.

[Ryan Stout]

Now I'm worried lol

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[Featherburner]

blackbirdws6 Brian, what are your feelings on this?

[blackbirdws6]

I've bent wheel studs twice but thankfully never sheared them off. First, what size stud are you running? If you are using the smaller ones that came with the rear then get those out ASAP (no choice now). I bent my studs my first time out at the track using ET streets and acorns. There is little support using the acorns so if you are putting down good power, its not ideal. I upgraded to the 1/2" studs (thankfully the axles are pre-drilled for them) and had zero issues running them with shanks.

I went to the track with my stock 16s with MT DRs using acorns and proceeded to bend the 1/2" studs. I called the manufacturer and they simply stated they shouldn't have bent....ok well they did. I'm convinced the acorns are the problem so after replacing studs once again (diff manufacturer), I purchased a set of ET lugs which are open ended, with a acorn base but with a semi shank. The little shank on the end has worked very well so far. Billet specialties sells them.

in any case, its important to make sure the studs are tight and the lugs are checked for proper torque in between runs.

[firebird_1995]

Great info, thanks a bunch. They are the stock size 12-1.5mm screw in studs from strange. This is an n/a motor, stock heads, cc306, th400 w/3600 stall, 3.73 gears, 275 m/t street comp tires. If we have 350hp going to the wheels we'd be lucky. Is there any strength to be gained by upgrading from 12mm to 1/2"? With the flanges being drilled and tapped for 12mm I'm concerned in order to go larger id have to go to 5/8". From what I've read, then wheel options become and issue.

[JPack]

I run open end acorns on 1/2 studs off the trans brake with zero issues on torque thrust wheels. I only had option of 1/2 or 5/8 studs on mine. How old is the rear end?

[Tyler Wheat]

Saw that exact thing at Tulsa about a year ago. Built LS with a 4L60E at that. It was weird too because those drag radials were about on their last leg. Sheared them almost smooth and the the tire went rolling past the car.

Get you some 1/2" studs for sure.

[blackbirdws6]

Great info, thanks a bunch. They are the stock size 12-1.5mm screw in studs from strange. This is an n/a motor, stock heads, cc306, th400 w/3600 stall, 3.73 gears, 275 m/t street comp tires. If we have 350hp going to the wheels we'd be lucky. Is there any strength to be gained by upgrading from 12mm to 1/2"? With the flanges being drilled and tapped for 12mm I'm concerned in order to go larger id have to go to 5/8". From what I've read, then wheel options become and issue.

Hopefully the axles are drilled for the 1/2" as well. Mine had two sets of tapped holes for the two sizes. 1/2" will be fine with most wheel choices.

[firebird_1995]

I run open end acorns on 1/2 studs off the trans brake with zero issues on torque thrust wheels. I only had option of 1/2 or 5/8 studs on mine. How old is the rear end?

To be honest I'm not sure. We bought it used from a member here on the forum a while back. What are you thinking?

[firebird_1995]

Saw that exact thing at Tulsa about a year ago. Built LS with a 4L60E at that. It was weird too because those drag radials were about on their last leg. Sheared them almost smooth and the the tire went rolling past the car.

Get you some 1/2" studs for sure.

These were sheared off so clean I could almost back them off the flange by hand. As a matter of fact I used a pair of 4" channel locks because that's all I had available.

[JPack]

I was told to use antisieze on the studs when torquing the nuts to get correct tightening. Dry torque vs. lubed will get different results. I was also told to use the correct pitch on the taper with a stock wheel. Since the stud is larger, if the right taper isn't into the heel fitting hub centric, it creates a knife effect and doesn't sit correctly in the wheel hole. Believe it or not Auto zone had the correct ones I needed. They let me in back and have at it. Have had zero issues on the old nitto 315, and have yet to launch it off the bottle and trans brake on the new 325 M&H tires.

[firebird_1995]

Ok. Are you running the mini shank or just a standard acorn?

[JPack]

Mini open end.

[JPack]

I believe they are called open end bulge acorn nuts

[firebird_1995]

So I got to take a good look at everything tonight. The flanges are drilled for both size studs so we are going to get some 1/2" ARP studs in there this time. I also checked both the flange bolt pattern and wheel bolt pattern and they are the same. I checked the drivers side lugs and was able to spin 4 off by hand and actually twisted the stud off with the 5th one. He had just just checked them with a torque wrench the run before and they were tight. The only time they had to have worked their way loose was from the pits to starting line. Only had a short burnout. So there wasn't much rolling taking place. Dustin (dangerous95lt1) said the screw in studs on his moser 9" came with lock washers installed. This rear end came to us (used) with flat washers only. When he replaced them the last time he used red loctite in addition to the flat washers. As much as I want to feel that is the reason for them loosening up, and eventually breaking, I can't look past the fact that he put hundreds of street miles (and launches) on the weld pro stars without them ever coming loose. I'm at a loss on this one....

[blackbirdws6]

The lug being tight doesn't mean the stud was tight as well. I've had my 1/2" studs loosen up even though I could still torque the lug nuts. The new studs have a 12 pt head which I was able to get much tighter than my old ones. I used loctite as well.

[OVA1]

So last night me and my dad took his car to the local 1/8 mile track to do some tuning. He's driving, I'm watching in the stands. First pass, tons of wheel spin, nothing impressive. Second pass, car rises up good out of the hole then gets crazy squirrely. I'm thinking to myself, "Jesus dad let off the throttle", well what happened was the passenger side wheel had come off! They got him off the track and when I got there I seen all 5 studs had sheared off. We started working on getting something temporary to get it back on the trailer and he tells me BOTH sides had sheared off the week before. This was on 10x17 zr1 rims with mickey thompson street comps, stock style acorn lugs, no spacers. Rear end is a strange s60 with a spool. Strange brand screw in studs both times. He chocked the first time up to the possibility of the lugs being loose, but the second time there was no way they were loose. He had just checked them the run before. So I don't think they were loose the first time either. I did some searching and came up with SEVERAL people that had the same thing happen. The common denominator being stock style wheels and lug nuts. Some had mentioned that strange/moser recommends shank style lugs. That makes sense because while running his prostars with shanked lugs he didn't have this problem, only with the stock rims/lugs. The issue I have with this is, how is it guys can run 1.5-1.4 60' on stock rear ends without shearing the studs but the "stronger" aftermarket rears with their brand studs cannot without the use of shanked lug nuts? Seems to me the fastener quality is to blame. Anyone had this happen or have any input?


Well that answers my questions on whether or not spacers were a good idea… I've got 5/8ths shank shouldered studs, but I ain't about to go through THAT! So now it's another set of rims… with the proper offset instead of spacing.

[firebird_1995]

The lug being tight doesn't mean the stud was tight as well. I've had my 1/2" studs loosen up even though I could still torque the lug nuts. The new studs have a 12 pt head which I was able to get much tighter than my old ones. I used loctite as well.

Ok that makes sense. Did you use a lock washer on the studs or just loctite?

[blackbirdws6]

The ARP studs I use now have a knurled face on the inside of the head if I remember correctly. I used whatever came with the studs along with loctite.

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[JPack]

Don't forget there are different angle tapers on the nuts. Stock wheel holes have a size hole that when a larger stud is inserted through that hole the taper of the nut sits in a different location. When torqued down if it doesn't sit right puts added stress on the stud. Instead of being closer to the bottom of the stud it sits out further and puts the stress further out on the stud. With the correct taper to allow for a smaller free area of the hole you get more surface area tension deeper. Same can be applied by enlarging the hole the difference in stud size. Just something to think about.

[firebird_1995]

That's a good point jim. I didn't look at the taper of the lugs that were on the car. Maybe the replacement nuts he bought were the wrong taper.

[JPack]

Comparison of a stocker and what mine are for a stock wheel on 1/2 studs.


http://i3.photobucket.com/albums/y77/jpack24/20130917_182433_zps5b89f838.jpg

[JPack]

If you do some digging you can find out more info. Most of the stuff you will find is for 60° lugs. But doing a bit more searching you can find out some interesting things.

For instance, see this....

http://summitracing.com/parts/rei-d60121

Note the size and degree as well as what it fits. Not exactly a normal 60° lug.

There are plenty out there to look at and make your own decisions. You really need the correct clamping force on whe wheel stud combo you run. Not all nuts are created equal.

I do lube my studs but I also account for that when torquing down and shy slightly looser. If you over torque a lug the wheel can knife into it and almost make it like a lock washer at the base. Lots of variables to consider. I just know what works for me on the wheels I run. I would not use the same lugs on a different type of wheel if I chose to ditch the street wheels. I also see guys at the track torque down a set of wheels before the first run. Bring it back and retorque them without cooling down completely. That is dumb. I just have had the luck of being around an old top fuel guy that when he spoke no matter what it was... I listened and listened good. Let me know what you find and maybe post up some pics of the damaged pieces. Sometimes that helps.