if it was me i would go studs. even if you change wheels you only have to get different nuts and your still in business.

 

im losin it dude. does this not say 14mm but in the description also say 17mm hex?

i need a 14 ( head size fit inside lug hole of wheel )_.x 1.5 x 40MM

NOT a 17mm hex? can you help pls explain that link please for me. it also doesn't offer a way to specify that i want a 40MM length!? though it lists that 3 different lengths are available


is bizarre or... i'm losing it lol

 

The shank size is 14 mm diameter, thread pitch is 1.5 threads/mm, and the hex size is 17 mm.

 

ok, but the hole will only accomdate a 14mm head. what am i missing here

this is ( i believe ) why i keep mentioning their difficulty to source. it is very hard to found a 14mm head. all of them are 14x1.5 then the length and oem head ( sorry not shank ) would be 17mm. forgestars isn't. it's gotta be 14mm ( the bolt head not the shank ) for the bolt enter the wheel hole.

 

Exactly. '02996ttx50, there is something unique to your setup/installation/usage that's causing this issue. The wheels are still hubcenteric even with the adapter ring (a lot of wheels use this. Can you verify that the hub ring isn't somehow holding the wheel off the hub and stressing the bolts that way? Like the chamfer is not too small or something? Can you get us some photos of the wheel face and hub face? And show us a picture of these 14mm head bolts you're using...

 

when you reference the "shank size". are you referring to the head of the bolt/shank itself? the very top of the lug bolt, yes?

the amzon listing seems right, but doesnt allow for the 40mm length to be specified in the order! . all else about those bolts (excepting the seeming inability to specify a requested shank legit of 40MM! ) seems correct for my needs. its where I'm stuck

 

yes, I've briefly tried that ( pics etc ). all anyone has been able to venture in terms of a guess, is indeed that the hob isn't fully flush against the wheel once fitted. and i have confirmed the hubcentric "ring"/spacer whatever we're calling it ( ring works ) is intact in the center of the wheel where it belongs! no movement play whatsoever!

the only way I've been able to "confirm" as you suggest is by ensuring it's ( the ring ) exactly fitted inside when the wheel goes back on. again, i've just had the rears off for r&r but have been using these wheels for at least 4 years now.
these issues only began when lateral stresses in an rwd configuration were explored 7/10's +/-. thats where I'm at, but i now have a good feeling based on pwdrhounds input that i have a UNDERtorqued situation regularly occurring?! coupled with the possibility that wheels really arent porsche specific. not at these stress levels. all I've got(??)

 

Head is the hex, shank is the threaded part

If you have clearance issues, socket head allen bolts are available. I still think you need a machinist or someone familiar with proper measuring equipment to check out the wheels, otherwise your problems will continue.

 

I'm not sure thats true nick!? though i obviously defer to your years as a tech! i think i may need to ultimately to get rid of the wheels as they may in fact not :"seat" as well as i need them to for the places/ways I'm driving, but i'm going to try again with that set of lugs above. torque em once a week to 110 or so, and see. i dont see a lot of other options, beyond simply new wheels. I'm also going to hand torque, stay away from ratty tire shop impacts etc. i dunno, tighten up the game and pay closer attention to them.. again! when i thought this was all solved, i simply got what i thought were stronger tuner hex head lugs, and they have been a vast improvement, i just need to be even more diligent. i push the car, and dont tighten/torque enough and possibly even enough ft lbs.

i didn't know porsche upped their factory recommendation for torqueing lugs!?!

anyway.. starting fresh in a couple of days; new lugs and new ft lbs# specs and we will see. thx for your input.

 

I don't think I see it mentioned, it is one wheel doing this or all four? Or just rears or fronts? I haven't tracked on my Forgestars, but never had an issue over the past 2-3 years with them.

Also, wonder if the wrong bolts initially may have caused a wheel issue that is now going to show itself with correct bolts.

 

not sure why your heads of the lug bolts won't fit inside the holes. mine are 17mm and fit inside my cf5 forgestar wheels with zero issues. if you want i can take a close up pic for you
to me thats the whole issue right there

 

that right there is a million $ question, and there's no way to know absent visible play. all torques/seats and installs as they should. since yesterday i'm running slowly but again rear tires have less than 100 miles so i'm scrubbing slowly and also am awaiting alignment for top mounts after a debacle with tarret camber plate install ) ( another story for another day )

so only happens on rears. ... BUT and this is progress!! ) i now only have ONE snapped ( like thats not enough.. ( using tuner lugs ) but another was visibly hairlined cracked approx mid thread(s)..

... and this is ALL since going rwd with lsd/wavetrac and pounding hills up/down with far more traction ( RWD w LSD!! ) than ever before. my solution before dropping a few k on new wheels is NEW lugs and a more stringent torquing spec and protocol/frequency!

but at the risk of repeating myself here, i'm awaiting new STEEL TUV certified lugs ( allen or hex, doesn't matter ) and torqueing to NEW specs MUCH tighter than usual 95 ft lbs. i'm at about 105-110 max now, but your point about some early damage possibly caused to the holes in the wheel is well taken, and not lost on me. the hub insert/rings are fine.

 

have no idea the 17 hex wouldnt fit. but a 14 hex does. with the same size bolt 1.5x40mm. just the head needs to be smaller.

 

Is there a photo of these 17mm hex bolts that didn't fit? My Forgestars came with 17mm hex bolts with 60 degree taper that fit fine.

 

the bolts that have failed are all garbage and i've put them where they belong, so there are no pics. i didn't bother keeping the last two tuner lugs that are faulty from the other day, because a snapped bolt isn't for me at this stage much of a souvenir. it's actually pretty disconcerting. but a 14mm allen head tuner lug is what is the latest to snap. not a 17mm hex.

several years ago when i first received my foregstars fresh off the boat, i had also ordered their ( as i called them at the time ) "shiny chromed garbage of unknown provenance bolts" that LOOKED great. all shiny and chromed with nice heads. my documentation of my issues with forgestars bolts were at the time ( 20111 maybe??) is/was well documented in here. the thread exists it just isn't active, though i should've just resurrected it.

i'm glad to hear you've had no difficulty with yours... yet. as for me, i am not out of the woods yet. btw..i've never said these bolts ( all of the ones i've tried ) didn't or don't "fit". they "fit" just fine.

a well known wheel seller of f'stars has/is calling f'star and also attempting to source bolts. the consensus developing seems to be that the lugs are not strong enough for the ways and conditions in which i drive the car AND that they are being undertorqued as pwdrhound and others have suggested.

i am not driving in a straightline down a freeway. whether this is unusual or anomalous isn't even a secondary point. it is though, a royal PITA and at the very least, dangerous.