Wheel nut torque 19 November 2022 at 10:11PM edited 19 November 2022 at 10:12PM in Motoring 24 replies 854 views

DanDare999

venomx said:

Good point about the impact or air wrench as you call it.

However I don't see overtightening a huge problem as lots of cars these days don't come with a spare wheel and therefore very unlikely car owners will need to take the bolts off unless you plan on working on the car yourself 

As said above if you really wanted to tighten to a spec, every car is different and it's unlikely that any tyre fitter will go to the effort of finding out what its supposed to be.

As advised after 25 miles then after 100 miles after new tyres I ensure the bolts are tight.

Are you another who sees no issue in them being over tightened?

Iceweasel

Pretty near everyone who doesn't use a torque wrench grossly overtightens the wheel bolts / nuts.

That's especially dangerous on alloy wheels.

venomx

DanDare999 said:

venomx said:

Good point about the impact or air wrench as you call it.

However I don't see overtightening a huge problem as lots of cars these days don't come with a spare wheel and therefore very unlikely car owners will need to take the bolts off unless you plan on working on the car yourself 

As said above if you really wanted to tighten to a spec, every car is different and it's unlikely that any tyre fitter will go to the effort of finding out what its supposed to be.

As advised after 25 miles then after 100 miles after new tyres I ensure the bolts are tight.

Are you another who sees no issue in them being over tightened?

Of course given the choice you'd have them tightened according to the manual but if my bolts were overtightened by a mechanic I wouldn't be loosening and then tightening them back up again for the sake of it. For my car anyway there isn't a specific spec, it recommends between 100nm and 150nm there or thereabouts.

I was unaware that over tightening is  bad practice but maybe I'm wrong. Why is it bad to overtighten ? 
Thanks

Iceweasel

Over-tightening can cause stripped threads on wheel nuts and wheel studs plus stretching of the studs, which makes them weaker and prone to fracturing and eventual failure. This stretching can also cause the wheel nuts to work loose.

GDB2222

My car is 16 years old, so I expect it's been subjected to all sorts of abuse. 

Richard53

Iceweasel said:

Over-tightening can cause stripped threads on wheel nuts and wheel studs plus stretching of the studs, which makes them weaker and prone to fracturing and eventual failure. This stretching can also cause the wheel nuts to work loose.

This. Have to say failure is very rare, because hubs and studs are built with massive tolerances to allow for lazy mechanics and inept owners. But nevertheless, if there’s a right way to do something, I’d rather do that than do it wrong. Manufacturers give you torque settings for a reason. 

The best one I had was a French mechanic who repaired a tyre on the MX-5 for me when I got a nail in one in the Alps. He fitted the nuts finger tight and then asked me what torque I wanted them to. I told him, and he got out his torque wrench, set it carefully, and tightened them precisely. He got a drink out of me for that. 

victor2

I've seen wheelnuts fail. Many, many years ago at my grandad's funeral on a bitterly cold day, we were in the car following the hearse when it lurched sideways, the wreath slid off the coffin and a wheel went rolling down the road because its bolts had sheared. His brother just said to me, in a broad Yorkshire accent, "eee lad, they need some new tackle"!

Grandad was late for his own funeral. Was the most memorable one I've ever been to!

B0bbyEwing

GDB2222 said:

I took my car in for a new tyre. They seemed to fit and balance it okay. Tightened the wheel nuts using an air wrench, and refused to check with a torque wrench. They said the Snap On air wrench was pre-calibrated to the right torque.

 It’s a palaver to borrow my son's torque wrench, so I just wanted to check whether they were lying to me about the air wrench?

What I tend to do when I know a garage has had my wheel off (unless I've been there & seen them torque to spec) is loose off the wheel nuts & re-do to spec with a torque wrench by hand, no power tools.

sevenhills

venomx said:

DanDare999 said:

venomx said:

Good point about the impact or air wrench as you call it.

However I don't see overtightening a huge problem as lots of cars these days don't come with a spare wheel and therefore very unlikely car owners will need to take the bolts off unless you plan on working on the car yourself 

As said above if you really wanted to tighten to a spec, every car is different and it's unlikely that any tyre fitter will go to the effort of finding out what its supposed to be.

As advised after 25 miles then after 100 miles after new tyres I ensure the bolts are tight.

Are you another who sees no issue in them being over tightened?

Of course given the choice you'd have them tightened according to the manual but if my bolts were overtightened by a mechanic I wouldn't be loosening and then tightening them back up again for the sake of it. For my car anyway there isn't a specific spec, it recommends between 100nm and 150nm there or thereabouts.

I was unaware that over tightening is  bad practice but maybe I'm wrong. Why is it bad to overtighten ? 
Thanks

My work Crafter van had a wheel stud snap four times. Same wheel.

flashg67

I used to work for one of the nationals and we had to torque to the correct setting from our manual & sign the job sheet to confirm. Not heard of a car that needs  a torque check after x miles - this usually only applies to HGVs but can't hurt.
Any garage that told me their gun was set to the correct torque would get called out by me - there is such a variance in torque settings on different models.
Overtightening can stretch the threads, eventually leading to stripping of the threads