Loose Lug Nuts

[engineer_gregh]

I've installed 20" Boss 338's on my longbed. Yesterday a guy pulls up next to me at a red light and informed me that my left front wheel looked to be loose. After I initially installed them I went back and checked for loose lug nuts at a couple of hundred miles and all was good. Now after 700-800 miles a couple of lug nuts were loose at all four corners. Anyone else have this problem with their over sized or after market wheels? This scared the crap out of me, the last thing I want is to experience losing a wheel at any speed.

[OrangeCrush1970]

Are they sleeved lug nuts? I ran into this last week for the first time....almost lost my passenger rear tire. I thought I had a blow out, lost 4 lug nuts and the last 2 were several turns from coming off. It was the first time this had happened and the wheels have been on this truck for years.

My only thought for you is that the lug nuts are a little too small for the lugnut bore in your wheels?? Did you use washers on your lugnuts?

[geezer#99]

Did you tighten them or did you torque them in to place?

[RManson]

Does the wheel have a flat surface (flat countersink) or is it tapered where the lug nut engages the wheel? You can't run a tapered lug nut with a flat countersink mag wheel. If they're tapered, make sure the lug nut taper is larger than width of the widest point of the taper on the wheel so that the lug nuts don't "suck" into the wheel's taper. That could cause a problem. My bet is the studs are too long for the nuts and they're bottoming out on the top of the stud just before they're tight enough, causing them to come loose.

Once you figure it out, be sure to torque them to manufacturer's specs. 90lbs is probably good. Don't rely on your impact, in fact don't even use an impact.

[davepl]

You can use an impact, just make sure you use a torque stick. I've always just used a torque wrench, but 32 bolts at 140 ftlbs is quite a workout, so I ordered torque sticks from Amazon. The reviews and mfr claims indicate they hit within 5% or so of the indicated value:

Amazon.com: TO405EXT - 5 Piece 1/2" Drive...

On your truck specifically did you happen to change studs? If they're "pulled" in with a lugnut that's bad, they don't always seat, then when you install wheels and drive it the studs get seated further in and now your nut is loose. That's why they need to be pressed in.

[leftybass209]

I hate to ask questions that seem common knowledge but along with all the above questions, did you tighten them in the correct sequence like a cross pattern or did you just go around in a circle? I've done that stuff in my mechanical infancy!

[engineer_gregh]

You bring up very good questions. Pictures are worth a thousand words. Are these the correct style lug nuts? Once I installed the wheels I took the truck to a local tire store and had them torqued as I don't have a torque wrench. I've put on hundreds of wheels and tires in my life time but never mag wheels so maybe I've got the wrong style lug nuts for these wheels. I didn't use washers, maybe I should?

[volksworld]

hard to tell from the photo...if the area around the lug nut hole tapers in at a 45 degree angle ,you have the correct nuts....if its completely flat,you need the nut and washer style....now,the nut and washer ones have a threaded sleeve that extends into the thick rim for adequate holding power,but the acorn style you show need the stud to extend out past the seat as far as they would have with thinner steel wheels...and they look too short in your photo

[engineer_gregh]

I went back and looked. There is a taper so the lug nuts are correct. I doesn't look like the lug nuts would bottom out and there appears to be enough threads to fill the nuts 75% or so. I'm not sure what the problem is. Maybe some of the other folks running Boss 338's could chime in, are they having the same problem and is so what did they do to remedy the problem.

[geezer#99]

You have the right lug nuts. 60 degree conical seat. And your studs look right. The nut needs to thread on a distance equal to the width of the stud. In your case that would be 1/2 inch.
Get yourself a cheap torque wrench and check them often. I torque mine when installed, after the first drive, after 50 miles and check again once in awhile.
Torque them in increments. Torque in a star pattern. Start at 50, then 70 then finish at 90.
Go over them again to be sure.
Over or under torqued nuts can cause rotor warpage not to mention the panic of a wheel passing you. Your wheel, the one that was on your truck!

[pwdcougar]

How smooth is the mating surface on the brake drum and hub? I had a problem with aftermarket rims not mating up to the brake drum leaving a space between them. The space was around 1/16". No matter how tight I ran the lug nuts in, the wheel would flex and the lug nuts would loosen up. Lost a rear wheel on with my then 3 year old daughter in the car. She is 20 now and I still havent told my wife yet.

Paul

[Fitz]

Originally Posted by engineer_gregh

Are these the correct style lug nuts?

Lugs look correct and the 60 degree taper lugs do not use washers. The thread pitch should be national fine, 20 threads per inch. For a grade 8 fastener torque should be 90 ft-lbs.

[engineer_gregh]

Thanks for the responses everyone. I put a dab of white paint down into the center of the lug nuts and torqued them down to see if maybe I was bottoming out, doesn't appear to be the case. I'm going to order new lug nuts and give that a try. Maybe the one I have are just cheap lug nuts. After a lot of reading I'm ordering McGard from Amazon, made in the US and based on my reading are very good quality.

Amazon.com: McGard 64000 Chrome Cone Seat Style...

[Front Range]

Revisting this topic.

Had the left front 35" tire come off at around 55mph last night around 10pm. Extremely fortunate to have no other vehicles in front of me and no oncoming traffic because the tire rolled about an 1/8th mile bouncing into the oncoming lanes until it crossed back over and into some bushes. Nothing quite like the adrenaline rush of steering on the backing plate with a rooster tail of sparks watching your big ass tire rocket off into the oncoming lane. I ended up ordering some of the extended seat Et acorn lugs with 60 degree cone seat. I'm hoping that will suck up some of the gap between stud and rim hole at the wheel seat. I don't think the basic acorn nut is keeping the rims seated because every now and again I will find a loose or missing lug. These are older American Racing aluminum rims.

Spooky.

[davepl]

If you're wondering what happens if the lug nuts come all the way off... it sucks!

Apparently they put new wheels on just before selling it and didn't hand-torque them, and I wasn't in the habit of checking new cars for tight lug nuts. I am now though!

[engineer_gregh]

Once I installed the McGard lug nuts I didn't have any more problems. I've since changed the wheels.

[firedemon]

chrome and especially aluminum rims tend to let the lugs loose for some reason I use a torq stick and check them often

[CST10]

Hard to tell by the photos, but I think those are shank style lug nuts with flats washer style holes.

I'd call the wheel manufacture and make sure you have the correct style lug nuts.

[garyd1961]

Looks like you need lugnuts with the shank/sleeve that goes inside the lugnut hole on the wheel. Some have flat shoulders but others have tapered shoulders with the shank which is what looks like you need.(DON'T take my word as fact, make sure you get the RIGHT lugnuts.) Never take chances with the wrong lugnut, always be sure to get the correct lugnuts for the wheels. I rotate the tires on 10 or 15 cars a day and have been doing it for years. I've seen torque specs from 45 lbs to 160 lbs for factory wheels but once you install after market wheels that changes everything. I wouldn't go past the factory specs though because the size of the stud usually determines torque specs.

[Front Range]

Originally Posted by garyd1961

Looks like you need lugnuts with the shank/sleeve that goes inside the lugnut hole on the wheel. Some have flat shoulders but others have tapered shoulders with the shank which is what looks like you need.(DON'T take my word as fact, make sure you get the RIGHT lugnuts.) Never take chances with the wrong lugnut, always be sure to get the correct lugnuts for the wheels. I rotate the tires on 10 or 15 cars a day and have been doing it for years. I've seen torque specs from 45 lbs to 160 lbs for factory wheels but once you install after market wheels that changes everything. I wouldn't go past the factory specs though because the size of the stud usually determines torque specs.

Yeah I'd say you nailed it. 60 degree seat with the extended shank. I measured out everything and picked up these with the .61 wide shank - essentially the acorn with extended shaft. I've had the flat washer style and these are definitely the 60 degree seat type. I had the Big O Tire shop install the rims when I first got them and they selected the acorn with 60 degree and no extension but I think there is far to much gap between stud and rim hole for a plain un-extended acorn.

Appreciate all the advice.

[Front Range]

Stock 7/16-20 RH studs, on a 77K10. Rims are the old American Racing AR-21 Directionals, often referred to as sawblades.

[Gromit]

I have the OEM 15 x 6 steelies on my 1970 C-10 LWB (or was it 5.5 or 6.5?) - anyway judging by the date code on the wheels they are original to the truck.

About nine months ago I removed and touched up the outer parts of the steel wheels with spray paint and then reinstalled and torqued them with a click type wrench to 65 foot pounds (star pattern, very meticulous since I am one of these torque Nazis)..Service manual spec is 65 ft lbs. and the stud threads were wire brushed and carb cleaner sprayed clean and no anti-seize, oil or grease was used - just bare metal studs and clean degreased lugnuts. Lugnut needs to be turning when the torque wrench clicks, etc.

Anyway nine months later just last week I was trying out a spare wheel for fit and when removing the original wheel was very surprised to note that the lug nuts had loosened up... So I popped off the other three hubcaps and checked the rest of the lugnuts and they had all loosened.

By loosened I mean maybe to about 20-30 foot pounds from the 65 foot pounds that I had put them at.

The GM 1970 Service Manual said to check the lug nut torque every 6000 miles.. (after checking them at 100 and 500 miles after a change) Well there you go I waited nine months what did I expect?

Partly joking there but this is the first time I have seen a whole bunch of lug nuts loosen on their own. I have the six lug and drum brakes.

It is a heavy vehicle? My MBZ w126 is heavier but those MBZ lugnuts never loosen so I don't know..

Here are the relevant pages to the 1970 GM service manual pdf - I think this is the Lubrication section pages 0-18 and 0-19

[In The Ten Ring]

You know, my car does this (daily driver). It didn't used to but then it started all of a sudden.

I would use a torque wrench and set it for 90 ft-pounds for my lug nuts (Honda Accord).

About 4 years ago I was driving and began to hear a sound, like a rubbing sound. I pulled over and decided to check the lug nuts. ONE OF THEM NEARLY FELL OFF and all were loose. So I tightened them.

The shop has no idea (Honda shop) what is up. What I do now to fix this problem is after I rotate my tires (every 6K miles) I tighten snugly and then recheck for snugness every time I go on a drive, usually just a couple of miles. I'll do this for a day or so and then the lug nuts stay tight.

The new problem is that I end up with lug nuts so tight, I need a cheater bar to get them off again! I use a long 1/2" drive SK ratchet as my lug wrench and I carry a 3 foot long piece of chain link fence post in my car's trunk as the cheater bar.

After I get my truck running, I want to build a bed tool box from wood and carry the same thing (along with all the other goodies I refuse to drive without).

[garyd1961]

I have to admit something. I've been working at dealerships for years and always torque lugnuts to specs but I never checked the specs on my 70 C10. Thanks to Gromit I now know 65 lbs is correct but I always torqued them to 80 lbs. I have been using 80 lbs for over 10 years with no ill effects and will probably continue.

[dmjlambert]

Thanks for this thread. It prompted me to pop the hubcaps off and check. I have plain steel rims with the old dog dish hubcaps and standard lug nuts. They were loose after less than 100 miles.