alright so to start off. The car is an sc300 and it was on stock oem studs for I'm guessing ever since the car was made.... when I bought the car it was running on some after market wheels that 18x9 or 18x9.5 all around. upon having the car for almost two month I soon upgraded the wheels to SSR SP3 front -18x9.5 and rear are 18x10.5 (Brand New made to order) it was torque down by feel (very positive it was tight) I used an acorn aftermarket lock lug on it. about a month down the road when I drove about 1000 maybe more miles 3 studs on each rear side broke off that both passenger and driver rear one day after another.(passenger side broke off got It replaced and then on the same day driver side broke after replacing passenger).... got it tow home and replaced the studs from advance auto part "DORMAN" one week later about 200-300miles drive, the driver side broke 2/5. got it replaced on the same day.. and then two days later about 200-300miles 4/5 studs broke off this time on the driver side as well. after replaceing the stud the first time which I thought It broke because of over torquing, so I started to used a torque wrench to torque it down to 70ft/lb

-yes I used a correct hub centric ring to make sure the wheel is sitting snugged on the hub bore.
-no I'm not running any spacer
-wheels were brand new made to order so I don't believed its bent or anything.
-I know dorman studs are crap but is it really because the stud are crap so it broke?
- do I need to get aluminum hub centric? though the plastic one I got fit extremely well and snug when mounted...
-do I need extended stud? but then my front are perfectly fine with stock length studs...
-do I need to order aftermarket studs that are stronger?

-I don't know why it keep on breaking.. 3x within a span of 2 weeks is ridiculous.... especially if its on the same exact hub.

 

If you aren't running spacers you shouldn't need extended length studs. Plastic hubcentric rings have always worked for me. There has got to be something else wrong. If you need stronger studs, I'd recommend ARP hardware.

 

Stock torque spec is 76 ft lbs.

Dorman studs are fine. You're either not mounting the wheel and centering it correctly when torquing down or there is something wrong with the hub/parking brake.

 

What process are you using to install your wheel studs? Are you blasting them on with an impact gun? That could be weakening them.

 

Not necessarily. I had to install extended studs in back for 17x9 Mustang Cobra wheels, as regular studs would only get something like 3-4 threads worth of bite. I'm sure there are other wheels with a similarly thick design around the stud.

As far as installing studs, the best advice I ran across is to put them in the freezer overnight and only take each one out as you're ready to install it. That'll shrink the metal enough to let it pull through with less effort. Also, take some fine sand paper or a small wire brush and clean out the holes first. The couple I didn't do that on were much, much harder to get the new stud to seat. It doesn't take much surface rust to really gum things up.

 

make sure the wheels are actually 5x114, always use a torque wrench, and go back and check them after a couple days.

 

? the wheels wouldn't go on the hub/studs if they weren't 5x114. also echoing what he stated, if you're having problems breaking studs then take as many variables out of it. torque the lugnuts in the appropriate triangle pattern and recheck after 50-100 miles. id also verify all the new studs are seated 100%. maybe try something other than doorman? I would upgrade to ARP just for the piece of mind since lower offset/wider wheels can shorten the life of wheel bearings and studs (I have them on the front of my IS, going to do the rear soon, they are super nice), but you will need open ended lugnuts. what type of lugnuts are on the car?

 

the proper way to install studs is with a hydraulic press. you can freeze the stud and heat the hub in a pinch. ideally the hub should be blasted and recoated if there is enough rust, but sandpaper and/or scotch bright followed up with a nice cleaning should work fine too (the rust will come back though).

not sure if the freeze/heat trick would work with ARP studs though as the ones I put in my IS had tighter tolerances and were difficult to put in. we used a good amount of the 10 ton press I had to make sure they were seated 100%.

 

Freezer trick works fine for ARP studs. I threw my IS300 studs in the freezer the night before and pulled them in using a lug nut and some brake grease. I lined up the knurls by hand and tapped the back with a ball peen hammer to center the stud and pulled in the studs using a lug nut and torquing it to 76 ft lbs.

 

 

Agreed seems very strange. I am more likely to believe the rims are the culprit.

 

5x112 could possibly fit, and be enough of a difference that when tightened would cause them to bend slightly... obviously putting a lot of strain on them.

OP, if these wheels are "made to order", why the need for hubcentric rings?

 

Most Japanese wheels are made with a standard 73.1mm bore. Made to order only means they don't make the wheels until he paid for them. It isn't like American made wheels where they drill the wheel to only fit your car.

 

Well, that's not my idea of made to order wheels, nor is it my experience with them. If it's just a wheel with predetermined specs that gets made on order, it's basically just an off the shelf wheel. Made to order, in my experience, is made to the buyer's choice of size, offset, hub bore, bolt pattern...