Lugnut Woes

Hey all!

First, a sincere thank you to everyone who replied to my previous post. Thanks to advice from you and the folks over at CKT Racing, I ended up purchasing a 2019 VLR chassis from another local racer. I’m thrilled to have bought my first kart!

Less thrilling, however, has been torquing the lugnuts. I don’t currently have a battery impact gun, and while I plan to purchase one in the future, that $200 needs to be applied to some other karting necessitites.

So I broke out my trusty digital torque wrench and got to cranking, and soon found that it’s basically impossible to put more than 35ft/lbs on the front wheels, and about 40ft/lbs on the back. The kart and tire just want to move under the force applied. So my question is, is there any clever way to keep the wheels from spinning? I tried chocking the wheels, applying weight to the tire with one foot, and this did help. However, I couldn’t get past that 35-40ft/lb barrier without the tires breaking free. Is there a better way??

That’s way too much torque for those wheels and lugs. 15 to 20 ft-lbs should be plenty in my opinion.

You can pick up a cheap 1/4” Harbor Freight for under $80

If using ratchet wrench, simply holding the wheel and tightening is going to get you enough install torque.

I wouldn’t use a rattle gun on lug nuts, it’s a good way to break a stud. Fine to do up to the first ugga dugga, but finish tightening by hand.

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Whatever torque you get with a ratchet and holding the wheel as tight as you can is enough.

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I disagree respectfully. Most wheel studs are made of steel. Most lug nuts for karts are made of brass or aluminum. You are more likely to strip the nut than the stud and usually the hex, not the threads. Ask me how I know! Rattle guns are fine, just don’t go overboard when tightening them. A 1/4 drive rattle gun can put out around 40 ft-lbs of torque. One or two blips is all you need to tighten a lug nut down once snug to the rim. Always keep spare nuts and replace them when you see the corners of the hexes starting to deform. This should ensure hassle free operation.

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I gotcha, I had heard 50-70ft/lbs so I was trying to get close to that figure. A quick google search for 10mm nut torque specs suggests a figure closer to the 20-30ft/lb range, and that seems to make more sense based on my experience of trying to get them much tighter than that.

@Don_Westlie: I was looking into a harbor freight brand, but read some reviews about the tools and/or batteries failing pretty quickly. Do you have any experience with them? Sounds like going down to 1/4" from 3/8" will save some money in any event though. The wheels felt pretty secure at around 15-20ft/lbs as suggested above, I just wanted to make sure that they wouldn’t come off on track.

@Billholt and @GregF: Definitely sounds like an area where a little caution goes a long way. Sounds like there isn’t too much risk to using a low-power impact gun, but definitely good to stay away from anything designed for heavier use! I’ll definitely keep an eye on the nuts though, don’t want to strip one at the track!

@mtbikerbob: Indeed, I did have it on the ground and chocked all four wheels with some wooden blocks. The rear was a little more compliant because of the weight of the engine etc–having a friend grab the brake is probably a good idea! I’m using the locking style nut I believe–I can try to grab a photo. I just ran across the barrel-type nuts earlier today, so those may be worth exploring! For the moment, whichever requires the lesser amount of torque is probably the winner for me.

Could you put the kart on the ground to do this? Rears you can also apply the brakes but fronts are tough to keep from spinning and apply force.

I might also ask what style nut are you using? If you are using the locking style nut I personally think they are more trouble than they are worth. I have ruined studs just trying to get the nuts on and off. I have switched to the barrel style that don’t lock onto the threads and it works fine, but you do have to make sure they are tight.

Remember you’ll want to research 8mm torque as that’s the size the studs are, even though the nuts use a 10mm socket (for the little ones). The important part is what the threads are when referring to torque specs.

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Also with respect, I have broken kart wheel studs with a battery rattle gun. Usually right before the final.
Stripping threads and Hexs is also something I’ve done.

Use a rattle gun with caution may be the edited post. I would still advise to a newbie to not use one to torque the wheel nuts, spin them on then finish by hand.

Do what works for you.

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I’m with @CrocIndy , don’t need to overthink this. I’ve never torqued my wheel nuts to a spec. Either just tighten as much as you can by hand with a normal ratchet or 1-2 ugga duggas on an impact and you’ll be fine. I don’t ever have issues breaking or cross-threading studs with an impact, as long as you start the nut by hand.

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I only ever tighten by hand with a 1/2” drive ratchet handle. You can also strip the stud from the hub with a buzz gun. Ask me how I know :grin:

I might undo them with a buzz gun if there’s one handy, but I’ll always do ‘‘em up by hand.

Use an adjustable zip tie looped around the front bumper mount & brake pedal to engage the pads & lock the wheels. The adjustables I use are decent size & have good strength.

ETA, this approach can also be used to hold the rear disc in place while swapping rear axles.

My old Makita 3/8" works great for these lug nuts. I just let it go until it stops spinning and then 2 hammer hits is plenty. Assuming the 8mm studs are 10.9 hardness, torque should be 37.6 Nm or 27.7 lb-ft. But the copper nuts will deform way before the steel studs.

I don’t use more than a 12v impact on wheel nuts. Excess force is more likely to cause damage to the wheel itself as opposed to the stud, unless you’re using something with super high torque, in which chase it could potentially damage both. Always start the nuts by hand, then the rest is pretty straightforward.

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@tjkoyen: sounds like this is the general consensus. If so, I’ll count that as a win haha. Putting a reasonable amount of torque on the bolts is easy enough by hand, so I’ll just stick with the old standby for German car maintenance: gutentight!

@Richard_Jacques: haha! Been there a few times with some of the fasteners on my car. Not the most fun I’ve ever had! :sweat_smile:

@WheelSpin: now that’s clever! Definitely going to use that trick going forward. Thank you!

@hallkbrdz: thanks for pulling those numbers up for me! I know just about everything in karting–including maintenance–seems to be done by feel, so having a reference point is super helpful as a beginner. I’ll keep the rest in mind for when I do finally get an impact gun.

@Muskabeatz: yeah, definitely sounds like much more isn’t required for this sort of thing. Sounds like the takeaway is as long as the wheels don’t pass you on the track, everything is good!

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Home Depot is currently running sales on 1/4 impacts from DeWalt, Milwaukee and Ridged for $99. Just in case you still want one.

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At that price a much better deal for those than the HF for sure.

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Anybody know the best way to remove a 100% rounded off cooper wheel nut deep inside a rear wheel?

Asking for a “friend.” :lying_face:

For anyone watching the nuts on an 8mm stud require a 10mm socket . . . so don’t use an 11mm socket. Just clean your garage, find your missing 10mm socket, and do it correctly.

Had a newborne crying in the background and I was rushing. Now we’re both crying . . .Face Palm :rage:


This is why Jerry forbade us from using the impact wrench.