How do you determine if a set of lug nuts will work with a S550 GT OEM Wheel?

[Fly2High]

All,
After purchasing a set of aftermarket wheels, I received a bit of an education from a person at Gorilla. From my understanding, the S550 Mustang GT takes a M14 x 1.5 bulge conical lug nut. It uses a 21mm socket.

I went on to ask several questions asking for a variety of lugs nuts they sell that might work in my application. The aftermarket wheels have a 32mm lug pocket which makes it challenging to use the OEM lug nut or any OEM replacement since they tend to have a 21mm socket and are about 30mm in diameter.

I went on to ask which ones would work for both OEMa nd the aftermarket and they stated that only the OEM style (30mm dia) lug nut could be used.

I decided to ask some questions and it appears that just because a lug nut is a bulge cone and is M14 x1.5 with enough threads and height to fit the studs is enough.

I also found an interesting discussion on a Corvette thread ( https://www.corvetteforum.com/forum...lugnut-question-bulge-conical-vs-conical.html) about the differences between the recommended use of either bulge or regular cone for them. They are able to use either because , it appears, that as long as the mating cone fully covers the wheel seat, it will be satisfactory.

What bothers me a bit is when I read about recommended lug nuts for OEM that, according to users, do not. At CJ Pony Parts, they recommend a 'small diameter' (not a spline so it is really not a small dia. according to Gorilla) lug nut (https://www.cjponyparts.com/gorilla-lug-nut-kit-small-diameter-black-2015-2020/p/WHLLN17/) that has comments indicating they do not cover the OEM seat. They indicate that , when used with a black set of wheels, some of the unpainted seat is shown. These are Gorilla 41148BC. I would assume this is also true for the other small diameter Gorilla nuts they sell (https://www.cjponyparts.com/gorilla-lug-nut-kit-small-diameter-chrome-2015-2020/p/WHLLN16/) or Gorilla 41148HT.

I do not have these small diameter lug nuts to measure. If you do, could I ask you to post the diameter of the lug nut?

Trying to take measurements off the screen suggests that the OEM replacement is about 30.8 mm in diameter which is close to my actual measurement of 30 mm on the Stock part. When I measured the 41148 image, I get a diameter of 23.4 mm. This would explain why a chrome rim on black wheels is seen. You will have 3.7 mm ring around the nut.

If you have the CJ Pony parts small diameter lug nut, could I ask for a close up of the lug nut installed with a attempt to shoot a photo of the lug seat with it?

I am sure there is also some undocumented specification for the load rating for the lug nut as well which we never see. I always wonder how Amazon or any site truly determines which lug nuts will fit and which do not.


My thinking is that even if the manufacturer stated it is a M14x1.5, bulge cone seat with around 1.4 or greater length, I have a feeling that still doesn't guarantee fitment. My feeling is that the diameter of the wheel's seat must also be taken into consideration and as long as the seat is filled, it will work. Having the seat exposed/not filled by the lug nut, could be asking for trouble.

Can anyone shed some light on this? I know most will just go by recommendation hoping the manufacturer/dealer has worked out the details.

If the depth or diameter of the seat is needed to determine proper fitment, why is it most dealers do not have this information and most if not all lug nut manufacturers do not post it?

Any ideas or thoughts are helpful.

Thank you.

Frank

Sponsored

 

[Fly2High]

To me, this is what is required for proper fitment, or at least what I feel is the minimum. there could be more.

1. Thread size (M14 or 14 mm)
2. thread pitch (1.5 metric)
3. seat style (in our case bulge cone)
4. seat angle (60 degree)
5. seat depth or diameter. Must fill the wheel seat.

I have yet to measure the OEM seat but will post it if and when I can. Might need to get creative with clay or some lithium lube to get an imprint on a lug nut (not for mounting) and measure that.

I think the idea of posting that a lug nut is regular or bulge is a crude way to suggest fitment. Unfortunately, the diameter of a bulge cone lug nut differs between brands. Some brands, like McGuard, do not even make a 21 mm lug nut and by going up to a 22, it could make the nut even greater in diameter.

I think, much like what was suggested in the Corvette thread, having a wider diameter nut such that some of the seat is in excess of what the wheel needs is fine. Having too little could be and I suspect is, a problem.

 

[Ewheels]

I believe any M14 x 1.5, 60° conical lug nut will work. (60° is pretty standard) I've used several different lug nuts and anything that stated M14 x 1.5 fit just fine.
I would HIGHLY recommend throwing the OEM lug nuts in the trash. That outer shell deforms so incredibly easily. I got a lug nut stuck in the socket the very first time I took my wheels off. I then got some steel ones from Autozone....similar result. Then graduated to forged steel lug nuts (Ford sells these, OP Mustang, Vorshlag, Monster Lugs, ect.) these are what you want. Again, any of these brands with M14 x 1.5 threads will work just fine.

Hope this helps

Also, I have the Monster Lugs Forged nuts which are extended, open nuts which have more thread engagement (theoretically better.) However, most serious racers use the shorter ones (similar thread count to OEM) and they never have any issues.

 

[Fly2High]

When I spoke to Gorilla, they seemed to indicate that a standard cone seat 14 x1.5 shouldn't be used for OEM. You need a bulge lug nut with the larger seat is what was stated for OEM. Now, for aftermarket, there were more options but still a bulge was indicated. Not all bulge have the same size seat. Some are larger and the OEM need a larger cone seat.

I do not doubt they work. I would just like to understand why Gorilla and other manufacturers are not suggesting what others seem to say work.

 

[Ewheels]

I think Gorilla and other manufacturers are simply covering their asses. The clamping force holding the wheel onto the hub does not change with a smaller seat. The contact area that the applied load is applied to is now less with a smaller seat lug nut which theoretically would mean the wheel sees more localized stress but I believe there is a pretty substantial factor of safety designed into these wheels to compensate for this. I have never heard of anyone having any issues due to using smaller-seat lug nuts.

 

[Fly2High]

If you look for it, some lug manufacturers post torque ranges for certain lug nut sizes. I have a feeling Ford enlarged the seat to dissipate the 150 ft-lb to get a 14 x 1.5 to work. I think I saw that the 14x1.5 normally is good for 85 - 95 ft-lb. To get it up 150, they used what I can only describe as a super bulge lug nut.

 

[Ewheels]

The required clamping torque is designed and calculated based on thread geometries and steel grades and this is all standardized within the industry. Lug nut manufacturers have to meet these standards in order to sell their product.

85-95 lb-ft is incorrect.

These values will vary from chart to chart slightly but not by very much.
Lug nut torque is not something up for discussion and debate. If the vehicle use M14 x 1.5, 10.9 grade threads, then the required torque value is 150 lb-ft regardless of wheels, lug nut brand, ect.

 

[NightmareMoon]

I've got aftermarket tuner wheels with smaller lug nut holes and seats, and aftermarket wheels with full size OEM seats (and factory wheels with factory seats). I've got 4 types of lug nuts in two sizes. Small diameter tuner lug nuts, open ended small diameter lug nuts, full OEM sized closed-ended lug nuts, and open ended Ford Performance OEM sized lug nuts. I do use the Gorilla brand, they've proven trustworthy and durable.

I don't have dimensions on-hand for the aftermarket lug nut holes or lug nuts, but if the OEM ones don't fit, then you're looking at those small diameter lug nuts the Gorilla guy mentioned. Most of the aftermarket wheels have small diameter seats. I was impressed to find the APEX wheels use the full size OEM seats, which was one of many selling points in choosing that wheel.

I've never had a lug nut or stud break or even loosen itself up when torquing to 150ft/lbs, and the Gorilla lug nuts are nearly as perfect as new (only minor damage) after hundred+ wheel set swaps. OEM lug nuts OTOH were starting to deform and the sockets were not fitting well before they got replaced with Gorilla equivalents.

 

[Fly2High]

The required clamping torque is designed and calculated based on thread geometries and steel grades and this is all standardized within the industry. Lug nut manufacturers have to meet these standards in order to sell their product.

85-95 lb-ft is incorrect.

These values will vary from chart to chart slightly but not by very much.
Lug nut torque is not something up for discussion and debate. If the vehicle use M14 x 1.5, 10.9 grade threads, then the required torque value is 150 lb-ft regardless of wheels, lug nut brand, ect.

I do not doubt you but don’t you find it odd that the Civic Type R uses a M14 x 1.5 and only requires 95ft lbs of torque?

 

[Ewheels]

I do not doubt you but don’t you find it odd that the Civic Type R uses a M14 x 1.5 and only requires 95ft lbs of torque?

That is actually very odd... I did not know that.
Well there's still other factors at play here. Coarse vs fine threads. What grade: 8.8 vs 10.9 vs 12.9. Lubricated vs unlubricated. Perhaps the seat size does in fact come into play.
Without being an engineer for this specific application and working for Ford, I guess the "best" thing to do is pick what wheels you want and get matching seat size lug nuts.
Do I think using smaller seat nuts on larger seat wheels will be an issue? No. Do I have mathematical evidence proving my theory? No.

 

[Kong76]

I do not doubt you but don’t you find it odd that the Civic Type R uses a M14 x 1.5 and only requires 95ft lbs of torque?

Maybe weight of the vehicle?

 

[TicTocTach]

Here are some lug nut measurements I took when finding new lug nuts for my OEM wheels:

Lug nuts by clair_davis, on Flickr


Left to right - LMR "tuner" lug nuts that come with their GT7 wheels; Gorilla 45148BC-20 forged long shank lug nuts, DPAccessories open end, and OEM lug nuts. The socket for the DPA lug nuts is JUUUUSSSST small enough to fit the GT7 wheels. The Gorilla lugs are only a little larger than the tuner lugs, but they're as big as the seats in the GT7 wheels.

 

[SheepDog]

Not sure if you guys have seen these but I've used them on both OEM and Aftermarket wheels with no issues. The seat is larger than most tuner style lugs. They are a 2 piece design and the seat is on a bearing so once it contacts the wheel, the seat stops spinning when your'e torquing them down. they make both hex and spline drive versions.

http://www.mcgard.com/product/black...-1-hex-or-65302-22mm-hex-installation-tool-2/

 

[Fly2High]

That is actually very odd... I did not know that.
Well there's still other factors at play here. Coarse vs fine threads. What grade: 8.8 vs 10.9 vs 12.9. Lubricated vs unlubricated. Perhaps the seat size does in fact come into play.
Without being an engineer for this specific application and working for Ford, I guess the "best" thing to do is pick what wheels you want and get matching seat size lug nuts.
Do I think using smaller seat nuts on larger seat wheels will be an issue? No. Do I have mathematical evidence proving my theory? No.

What makes me think that wheel material plays a big part in seat and lug size is when you look at the recommendations for lug nuts.

For steel wheels, a standard cone will work.

For steel and aluminum wheels they always recommend a bulge cone.

This, to me, screams materials matter. I have no idea what property of steel when compared to aluminum allows for a smaller seat but it appears it can

 

[Fly2High]

Tictoctach,

Cool. Thanks you for those measurements

Frank

Sponsored