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Vehicle Electrics / Re: Auto lock
« Last post by zoomzoomer on Yesterday at 11:23:23 AM »
Just to clarify mine does it when the driver's door is last to be closed. it may be the time between turning ignition off and  closing the  door if it's too quick  it doesn't always auto lock, will have to take notice  next time.
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Hi should my trim level Mazda 3 have visual parking sensor
On my MZD it only has rear parking sensors
Am I right in saying it only has it when you have front sensors as well

Thanks
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Vehicle Electrics / Re: Auto lock
« Last post by yarb on Yesterday at 10:54:42 AM »
Seems with mine if I walk away as the wife is getting out of the passengers side the car (and she’s slow getting out most times) it will not lock automatically, if I wait by the car until she’s got out and all the doors are close the car will lock ok
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Mazda 3 / MOVED: Airbag warning light
« Last post by Willpower on January 16, 2018, 11:13:24 PM »
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Wheels/Tyres / Re: 80 to 108 !!!
« Last post by misar on January 16, 2018, 10:15:38 PM »
An interesting question, which I also asked some 12 years ago with my Gen 1 when we didn't have the tyre gunk option and had no choice but to change the wheel at the side of the road.
 
At the time, the dealer informed me that they were instructed to torque the wheel nuts to between 100 ft/lbs - 135 ft/lbs (a margin of 35ft/lbs). But this is in a considerably higher range than you have been quoted. 
As it is, your margin is only (28ft/lbs)

The problem as I see it is, the torque applied, has got to be subject to the inherent tensile strength of the bolt. But perhaps with modern casting methods, the specification of the wheel bolts has been reduced over the years.   

If I were in your position I would consider using the middle value, i.e  somewhere around 90ft/lbs.

The thing is, 28ft/lbs is quite a lot, it's 35% of the lower end of the recommended scale, that seems a lot to me. I'll probably go with 90ft/lbs but I'm surprised that Mazda {and probably other Manufacturers} can't/don't nail it down closer than they do.

As for the tensile strength of the steel, well Mazda would know that within <1% my concern is the nut runners over torquing and damaging or stripping the studs.

I am not an engineer but surely the range is set by two different factors. The low end would be the smallest torque required to ensure the nuts don't come loose. The high end would be the maximum torque before you exceed the tensile strength of the bolts or strip the thread - or in the case of alloys distort the rim or the stud hole surfaces.

Hence any value within the range is fine but the key issue is to be above the minimum recommended. This might depend on whether the wheel is steel or alloy and also the shape of the nut/wheel mating surfaces.

Feel free to discuss further!
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Wheels/Tyres / Re: 80 to 108 !!!
« Last post by misar on January 16, 2018, 09:03:36 PM »
I looked in two owners manuals:

2010 (Gen 2)
Nut tightening torque
N·m (kgf·m, ft·lbf) 88 ― 118 (9 ― 12, 65 ― 87)

2013 (?Gen 3)
Nut tightening torque
N·m (kgf·m, ft·lbf)
108—147 (12—14, 80—108)

So my Gen 2 is the same as Willpower's Gen 1 but later models went much higher as in the thread subject.

No mention in either manual about alloy versus steel wheels but if any models came with steel I would have thought the torque should be different. Mine has alloys but no idea what torque has been used.

PS I just noticed the OP's name and flag! I wonder if the wheel type varies between N America and Europe. However, the 2010 manual I quoted was a USA download but the 2013 one was a UK download.

PS2 Google found some tyre supplier recommendations:

Continental Tyres chart (2015, USA)            Torque in Nm
                                                         Steel rim     Alloy rim **
Mazda all current types – except *        103             103
* CX-5, 3 2013>, 6 2013>                    128                –
* MX-5                                                    98               98
** Please observe different specifications of rim manufacturer where required.

Pure Tyre (2018, UK)
Wheel Nut Torque setting for: 09 - 14 Mazda Mazda 3
(All tyre options)
Torque:  103 NM,  76.0 ft-lb

So 103 N.m falls nicely into the 2010 set of Mazda values whereas the Continental 128 N.m for steel is in the middle of the 2013 range. I would be inclined to go for 103 N.m unless I found specific advice to go higher for my alloy rims.

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Maintenance / Re: Mazda 3 2.2 awful mpg
« Last post by misar on January 16, 2018, 08:39:38 PM »
Unless there is something you havn't mentioned, like many very short trips, it must be doing very frequent regens to get the overall mpg down to 35-37. If so I suspect you have worse problems than poor mpg.
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Wheels/Tyres / Re: 80 to 108 !!!
« Last post by moozmooz on January 16, 2018, 08:25:40 PM »
"Forming round bar into bolts, has no effect on the inherent strength of the steel" Absolute rubbish. The various heating processes, including drawing, forming and threading, along with quenches during the processing are what determines the final molecular and physical properties of the steel.

"It's also unlikely that stud size and offset or wheel size would have any relevance" Wrong again. Think of basic mechanics/principle of the lever. Different wheel size and tyre size will exert different loads at the studs, as will different ride height. Think back to the days of wide boys fitting spacers and subsequently having their wheels fall off due to overloaded/failed studs as one example.

"As for the tensile strength of the steel, well Mazda would know that within <1%" I wouldn't bet on it. They'll most likely specify a minimum tensile strength. Anything over that is an increased safety margin they're not particularly interested in and don't pay for.

"I hear what you say, but, if that was the case why don't they say that in the Manual ?" The manual isn't specific to any one spec. What I find pretty disgraceful is that the manual doesn't even attempt to make clear which parts apply to which spec, something that in the computer age would be very simple to do.

On torquing in general. In more years of motoring than I care to remember, I've never used a torque wrench on wheel nuts or studs, and nor did garages/tyre fitters until fairly recently. How often do they check the calibration of their torque wrenches? Many are probably no more accurate than you would achieve using a known wheel wrench/known force.
Everybody will have experienced the rock solid nut/stud due to moronic use of air spanners, and some will have been unfortunate enough to experience the consequential failed studs.

I'd tend to let the garage get on with it, but if you're really bothered, check the nuts for tightness after the service, and, if necessary, back them off slightly and retighten them. If they're rock solid and won't move, go back and ask them to refit them so that you don't need a length of scaffold pole to loosen them.




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Wheels/Tyres / Re: 80 to 108 !!!
« Last post by Willpower on January 16, 2018, 08:09:20 PM »
Doing a bit more searching amongst data referring to my Gen 1  I found this .


Wheel and Tire Installation
1.   When installing the wheels and tires, tighten the wheel nuts in a criss-cross pattern to the following tightening torque.

Tightening torque
88.2-117.6 N·m {9.00-11.99 kgf·m, 65.06-86.73 ft·lbf}


Of course the first and very obvious item is the discrepancy between what I was told verbally and what is written here.  Quite bizarre...   

However what strikes me is the value shown in N-m  i.e.   88.2 - 117.6 N-m     Are you sure it said ft/lbs in your manual ?   because the values shown here are not too far away from those you quoted in your initial post, but in different units.

I shall see if I can find anything further relating to the Gen 3
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Wheels/Tyres / Re: 80 to 108 !!!
« Last post by Canada_Bob on January 16, 2018, 07:09:57 PM »
Can't say without looking, but the stud size and offset may be different from Gen 1 to Gen 3. The range might also be to allow for different wheel sizes.
I hear what you say, but, if that was the case why don't they say that in the Manual ?
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