I’m looking for technical help or recommendations on: Wheel nuts
This is a weird one. A couple of months back I changed my rear brake pads myself. After driving for few days i found my lock nut was missing on the side at which i did my brake pads. I assumed I failed to set the right torque on that nut and hence it came loose. I replaced it with a normal nut (this time i torqued upto 140Nm and no issues for a while. Randomly yesterday I again noticed one of the nut on the same wheel to be missing. I am going to replace it again, but just want to know if anyone has experienced something similar. Fyi the thread on all the bolts appear to be fine. Any thoughts on this are much appreciated
What wheel nuts are you using, standard chrome one’s?
Someone taking a shine to your wheel nuts (nicking them) although the locking one loose seems odd.
I always use 110 like my other cars and have never had a wheel nut come loose.
Are you on correct MX5 wheels or are they aftermarket wheels ?
Are they genuine Mazda wheel nuts ?
Just asking because some aftermarket wheels need round rather than taper nuts.
Are you sure that the brake disc is seated correctly on the hub? No rust between it and the hub. This is a classic scenario of wheel nuts loosening, you’re torquing the disc up against rust build up and over time the rust works it’s way out and the wheel becomes loose.
Sounds like somebody is playing silly buggers. Have you upset any of your neighbours or are there any miscreants that frequent the area? Maybe a friend with a twisted sense of humour? I’ve driven cars for hours that I forgot to torque up after work, and the worse I ever got was a bit of wheel wobble appear to remind me. Not saying it’s impossible but I doubt that a single wheel nut could undo itself all the way and go missing while the others stay there quite happily.
Lastly: Are you 100% certain you’re not going completely mad?
Some tyre shops over-tighten wheel nuts when refitting wheels- my son in law lost a wheel after having a puncture repaired, wheel nuts over- tightened and threads stripped.
Have a look at the threads on the one that keeps loosening.
Yes some tyrefitters use their impact wrench at max torque on the first nut, then when they tighten the others it stresses the wheel across the face of the hub.
If I have to let anyone else take the wheels off my car I always loosen and then torque the wheel nuts correctly afterwards.
Thanks a lot for your thoughts. I park my car in my apartments secured carpark and I really don’t suspect that someone is playing silly games (hoping not be wrong on this one). My wheels are all stock. When I removed the wheel for changing the pads, definitely the torque levels were high. But then I set it about 120Nm. Then I found the lock nut to be missing with few days. Hence, I was certain it was my mistake.
Looks like rust is the culprit. There was a lot of rust build on the hub, i just removed them on both rear wheels and will now replace the nut, I think that should do it.
Make sure that the spigot is clean too. For belt and braces, if you want the work, remove the disc and check that it’s all clear between that and the hub too.
Just an update, even after a bit of grinding I did myself with a wire brush on the hub (for removing rust buildup), my wheel nuts still have a tendency to come loose by themselves. As pointed out, my discs are quite worn too. I am considering changing the wheel hub and discs, is it worth to do them to sort this issue out. I am more or less convinced that it is mostly the rust build up on the hub that is causing this. Please let me know your thoughts
There shouldn’t be a need to replace the hub or disc. If everything is clean and the wheel is being fitted and torqued correctly the nuts should not be coming loose.
When you did your brakes, did you take the disc off at all, or move it compared to the hub? Rust between the hub and the back of the disc is one thing that people have suggested here? If it’s not that, have the wheels been refurbished at all? If so, and there’s paint/powder coating on the conical seat where the nut goes, then that can also cause them to work loose - that should be bare metal against the nut.
From memory my ND calls for 130Nm on the wheel nuts (I’d have to check to be sure, but I think it’s that), so your torque doesn’t sound wrong to me. (Other cars I’ve got/had are 120Nm and 140Nm).
Final thought; do you trust your torque wrench? Could it be that it’s miles out?
Okay, I do agree if the rust build up is not cleaned properly the wheels might not sit flush against the hub. I am not pretty satisfied with the rust removal job i did either. So will put a another weekend into this and hopefully will be able to fix this.
