Any idea what would cause this? Over the course of 100-150 miles they will loosen about a quarter of a turn. Every single one of them.. Alignment, balance, bushings all good. Cleaned the studs. Im lost.

 

Wrong size lugs?

The proper way to torque wheel bolts, is actually to torque them, drive 50-100 miles and retorque them. After you tighten, do they come loose after another 100 miles?

 

Ive had them on there for a few years now and only have this problem in the last couple months. Its a constant thing, they just keep coming loose.

Is it possible to have a horribly out of balance tire (or tires) and not feel it? Car drives as smooth as a brand new car. I take really good care of it.

 

Normally the Lug nuts are Torqued to the specs recommended inside your owners manual.
For instance on my New Blazer it says 140 Ft. Lbs.
The Monte has a sticker on the door or on the spare door someplace that indicates 100 Ft. Lbs.
If you over torque them there is the chance or warping the rotors. If you are not using a Torque wrench to tighten them you need to get one.
Set the wrench for the proper torque and then when you tighten it you will here it click, give it another click and it should be good to go.

 

How does the hub and rotor mounting surface look? If those are nasty / rusty, the debris could be coming off as you drive causing less tension on the stud.

Are they good quality lug nuts? Thinking if they were some ebay special garbage that perhaps the threads are failing and relaxing due to creep.

Any other clues - any changes you made around that time? Is it all 20 nuts, just 1 axle, 1 wheel etc?

 

https://montecarloforum.com/forum/ti...ud-help-60700/

Last year you were talking about replacing the lug studs. One of the comments mentioned that they might be too long if you are running a capped lug nut. Did you ever go through and replace your studs?

 

That's a good point, especially if you put those eBay specials on.

 

Mating surfaces are clean and I had the ebay lugs on for a month or so around the time I made that topic. Took the spacers off and replaced the studs with the stock ones after about a month.

I think ive got it figured out.. I got an alignment about 4-5 months ago and im thinking they used an impact. I went there yesterday to ask about it. They said they use torque wrenches but I could clearly see the workers buzzing away with impacts. Could that have damaged the threads inside the lug nuts?

The nuts themselves are whatever they used when I bought my wheels, no idea where they come from but I assume they use whatever comes cheapest for them.

 

Did they have torque sticks, or just sockets straight on the impact?

Hard to say if that's the cause even if they didn't use a torque stick, although if the timing lines up, theres probably some correlation. Just saying there's a ton of shops that bang lug nuts on with impacts every day, yet you don't see hordes of people with this issue (not that it makes it right).

Maybe a combo of that and cheap lug nuts to start with?

 

I'd say it's worth buying a pack of 5 good lugs, and putting them on one tire. See if they stay strong while the other loosens. If it does, buy 15 more haha