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Lugnuts

4K views 19 replies 10 participants last post by  BobT 
#1 · (Edited)
Milous,
I do wish you would correct the lugnut size on Jeep Grand Cherokee WK2 - 2011-2014 Grand Cherokee Wheels and tires . The page states that the lugnut size is 1/2" X 20 whereas it is actually M14-1.5. They are not interchangeable. Also, the torque is 110 ft-lbs (150 Nm).

I'm talking about a 2012 Australian export WK2 but I can't imagine that US vehicles have imperial lugnuts when the rest of the vehicle is metric.
 
#9 ·
#12 · (Edited)
Metric thread measurement is taken from the nominal outside diameter of the thread on the bolt or in this case the stud. So if the outside diameter of the thread measures near enough to 14mm then it's an M14 thread and if the lugnut screws on smoothly all the way without being forced or without rattling, it is an M14 lugnut. Beware of 1/2" thread lugnuts. They will start to screw on nicely giving the impression they are correct but after 2 to 3 turns they will bind. Don't force them, through them away. They are no good, even dangerous for metric Jeeps.
 
#13 · (Edited)
Greetings,

The current edition (as of 2/9/2015) of both the 2014/2015 Owners Manual and the 2014/2015 Users Guide shows a Lug Nut Torque of 130 ft lbs (176 N·m).

What gives?

I was told by a tech at the Jeep Service center the service manual said 100 Ft-LBS +/- 15ft-lbs (also Milous' Page, Jeep Grand Cherokee WK2 - 2011-2014 Grand Cherokee Wheels and tires, Shows the same).

LINKS:
(Note, these Links are to the latest editions: If this is an error and it is corrected, someday, the links may take you to corrected editions.)

2014 Grand Cherokee User Guide
2014 Grand Cherokee OWNER’S MANUAL

Note: My Pet theory on this is, the Italians said the torque should be 130, only they meant Newton Meters(N-m) not Ft-Lbs.
 
#15 ·
I noticed the increase too. Maybe they are using higher grade studs now or maybe after four years of maintenance experience they are feeling confident enough to raise the torque. I wish they would specify whether the torque setting is for lubricated or un-lubricated studs. My guess is that it's for un-lubricated since few owners or mechanics would bother to lubricate. I'm one that hates unscrewing seized nuts so I lubricate the stud thread and the cone surface. I use any old bearing grease. Fancy anti-sieze is just grease with flecks of metal and a waste of money for this purpose. I read somewhere that with lubrication, 25% more of the torque goes into tensioning the stud. This provides a greater clamping force. However, with lubrication, there is the danger of over-tensioning so for the moment I'm sticking with the lower torque figure until this issue becomes clearer. This link provides an interesting read Wheel and Hub Failures .
 
#14 ·
^^That's a good point, probably were thinking in N-m instead of ft/lbs. Otherwise the specs would seem to be going higher and higher with each revision.


DOES anyone know if we need the BULGE style lug nuts or regular is fine? I am trying to replace them on my stock rims 20's, and have some McGard lugs ready to go, just have to pick the style: McGard Hex Lug Nuts - Best Price on McGard Hex Head Cone Seat Lug Nut Set - McGard Conical Seat Hex Lugs


I tried searching but they were for aftermarket wheels, need help for OEM replacement.
 
#16 · (Edited)
Never over lubricate the studs or the mounting pad.
Never lubricate the seat or angled portion of the nut as the tension and friction is relied on for it to maintain that torque, and establish a consistent value across 20 nuts. Even 1/5mm of grease, oil, dirt means the two parts meant to make contact and stay put are now separated by a layer of lubricant intended to keep two things apart, or make two thing slip, that's not a good thing.
Fluids do not compress so any torque reading with a even a single wind of threads covered in say anti-seize can throw off a reading significantly. Or a dab of oil or grease in the wrong place.
Whether or not it's a big deal to some or any it's 100% real to avoid a false bottom on any bolt.

All of the factory values are established with a clean dry surface, changing those conditions is factually not good.
That being said I clean my nuts and seal everything with different products, but anything past barely wetting the metal and wiping down is not as good as people assume.

We use a 60* Bulge seat style of a cone/acorn style lug nut, meaning it has a defined ring around the base or seating surface.
Good info and right at the top it shows the difference.
http://ecx.images-amazon.com/images/I/A10YUI3XVcS.pdf

20 Gorilla EX Large Seat Factory Stock Wheels Lug Nuts 14x1 5 Acorn Rims Chrome | eBay
If this is the right link these are replacement lug nuts, same size and shape as stock, not a generic acorn that's too small. They're available in black too.
Have fun
 
#17 · (Edited)
There are certainly many opinions on whether to lubricate wheel nuts or not. Whichever way one chooses to go there are arguments for and against. This link shows the dilemma 928 Tech Tips . Note that the Porsche technical bulletin requires nuts and studs to be lubricated with Optimoly HT. This is a light anti-seize like product that is now marketed by Castrol as Optimol T, see http://www.poulsen.is/assets/Veladeild/oliur/PasteW-tds.pdf . Note also that Porsche state that applying this product does not affect the tightening torque which they specify as 130Nm (96 ft-lb). My 2012 export WK2 specifies a torque of 150Nm (110 ft-lbs).
 
#19 · (Edited)
I really want this to sound like I agree cause I do, I get a little nuts about small things that end up causing someone a pain in the ass due to misinterpretation. It goes both ways...That someone could be a service mgr listening to a customer with "missing lug nuts" screaming how it's because jeep used cheap capped nuts... Even when asked and he explains the grease flung all over, he insists that no it's not that he read to grease his nuts on a forum so he packed them full of bearing grease, but it's a warranty issue? :) Once a week.

I'm very familiar with Porsche rituals but this is part of the point. Porsche designs this parameter into the equation and uses a specific "lubricant" and process to maintain that result.
Again I agree with a cleaning and a coating but a thorough wipe down with nothing but barely a film of a specific product is key. No high pressure lubricants, think thin film..not grease. What are you trying to accomplish? I want my nuts to stick.
Google hydro locking, it happens on all levels, microscopic.
Jeep nuts are measured dry as are the majority of torque vales. Meaning in any situation other than clean and dry the reading and hold will just be different, just a point not an argument, how different? 2% or .00000002%? I dunno

People still screw this up major, ask a Porsche tech how they feel about owners or independent shops interpretation of smaller procedures, or grease on carbon rotors.

It's better sometimes to keep certain things simple due to our tendency to overdue, overthink, overreach, vs. the benefit, "if a little is good then a lot is better" wins very often..We all are guilty....but jeep owners are king of the I can't leave crap alone hill. Come on how many of us touch anything that's burning hot right as were told, "don't tou......" We are pioneers
Absolutely maintain your nuts, a wire brush some spray cleaner and a proper lube, but it's actually less than less is more.
Sorry guys Im rambling cause I really don't want to go back to work, it's too nice out 65* light breeze from the NE, clear skies, bright sun, and calm seas. Anyone fish?
How's your weather.
 
#20 ·
Sorry guys Im rambling cause I really don't want to go back to work, it's too nice out 65* light breeze from the NE, clear skies, bright sun, and calm seas. Anyone fish?
How's your weather.
65°F is like 18°C. I'd have to put a singlet and jumper on. Here it got to 27°C(~81°F) today and partly cloudy. If it wasn't for the fact that my six-pack has turned into a one-pack, I wouldn't be wearing a shirt.
 
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