Torque wrench for lug nuts - necessary?

[TQ60]

If they repeat 10 times and stop at the click properly the torque is correct.

If they continue to turn any bit after the click on the first or any other time it is over done.

However at 475 it will require a bit of work to make it off...working battery terminals at inch pounds with small fasteners in lead alloy is a whole nutter thing.

[Ray,IN]

According to information in this Accuride wheel pdf, one torque does not apply to all heavy duty truck rims. Even the same size rims with a different use has a different torque requirement: http://www.accuridewheelendsolutions.com/files/2012/09/Accuride-Wheels-Product-Catalog-Summer-2011.pdf
Page 36.

[wa8yxm]

I have seen mechanics claim "I can torque it by feel" but.. I've then taken the vehicle to another location and applied a torque wrench (I have two of them on board) and found out how far off they were.

I know some impact wrenches (Electric ones) have settings, I've seen them twist off a bolt.

So I vote for the LOVES method of doing it right, and yes you should re-check shortly after.. The dealer failed to tell my daughter that.. Cost them big time. (on a car, yes this applies to cars as well).

[alank]

It's been quite some time since I was into some very specific torqueing, but I remember reading about torque spec's are normally given for dry fasteners.
I may be corrected on the ratio, but if you oil the studs or nuts, then the torque would need to be reduced to 80% of the specfied amount equal the same amount of pull on the fastener.

[twinboat]

It's not just the pull on the fastener, it's the stretch.

Back when I was rebuilding Cat engines the main and rod bearing caps used a very low torque and then instruct you to turn the nut a specified amount of degrees, beyond that point. This action put the proper stretch on the fastener.

If you stretch to far or to often they go soft. I had a 855 cummins head bolt stretch on me at 380 ft lbs. Not a good feeling when you think you pulled the threads out of the block.

A new bolt took the torque.

[TeJay]

I've been in this industry for 40 years. Most of what I've read says to torque with clean dry threads. Yes adding any lube changes things. Some times they say lube with a light machine oil. If it does not say to lube then the threads should be clean and dry.

I have never read any percentage to change a torque if a lube is used. Not saying there's not one.

There are many, many variables which will effect the final torque setting on all but the newest bolts which are called "Torque to yield" (TTY)bolts. They can only be used once but they are very accurate. It is for that very reason there are way to many variables that the TTY bolts were used.

You can't keep these aluminum engines together if you try to use standard bolts. And there are to many incompetent technicians who won't follow proper procedures. So the industry adopted the TTY bolts and eliminated problems from techs who wouldn't follow procedures.

TeJay

[Ted Lambert]

Originally Posted by Luv2go

IMHO torquing is necessary. I use a 3/4" socket set from HF and a 4' pipe as an extension. My son and I torqued the wheels about 6 months ago, he weighed 100 lb at the time so just stood on the end of the pipe for 400 ft lb. He's grown some more so we'll have to do some math the next time!

Your not serious are you?

[Ray,IN]

Originally Posted by TeJay

I've been in this industry for 40 years. Most of what I've read says to torque with clean dry threads. Yes adding any lube changes things. Some times they say lube with a light machine oil. If it does not say to lube then the threads should be clean and dry.

I have never read any percentage to change a torque if a lube is used. Not saying there's not one.

There are many, many variables which will effect the final torque setting on all but the newest bolts which are called "Torque to yield" (TTY)bolts. They can only be used once but they are very accurate. It is for that very reason there are way to many variables that the TTY bolts were used.

You can't keep these aluminum engines together if you try to use standard bolts. And there are to many incompetent technicians who won't follow proper procedures. So the industry adopted the TTY bolts and eliminated problems from techs who wouldn't follow procedures.

TeJay

The Accuride pdf about nut torque I linked to says the same thing about when to use light oil, and where.
Spring shackle bolts is another TTY use, even an otherwise competent shop often ignores that.
I will not re-use head bolts/studs, even in a cast iron block. The saying "penny wise, pound foolish" comes to mind.

[CVO]

First, it makes a big difference if the wheel is stud mounted or hub piloted. Stud mounted are to have clean dry threads for proper torque. Hub piloted which are centered by the hub and use 2 piece flange nuts are to be lightly oiled for proper torque.

I worked for a company that did testing for Michelin and Accuride with it's semi fleet. The latest standard was to put a few drops of 10W30 motor oil on the stud and the flange of the nut. Not WD-40, antiseize, or whatever else is on the toolbox. Torque sticks were tested with good results if the air gun, hose, and air system stayed consistent and was tested often. There was a high failure rate of the torque sticks. The final determination was to hand torque all wheels with a torque wrench that was calibrated regularly.

Here is a good article that addresses the issue.


Tips to Prevent Wheel-off Incidents on Heavy Trucks

[TeJay]

Ray,IN,

More interesting points. The torque to yield (TTY) bolts are torqued into their elastic limit and therefore will not return so must be replaced. They did that so that every bolt would achieve the same clamping forces regardless of all the variables associated with torquing bolts, especially ones like head,intake and manifold. One does have to worry about: lubrication on threads, dirt, thread condition,technicians incompetence, torque wrench and it's accuracy.

As far as reusing cast iron head bolts I guess one can be supper careful but as long as you never get into the elastic limit of the bolt it never seemed to matter. We did hundreds of engines and only broke head or block bolts when a student didn't know/remember left from right.

I guess the IN in your handle means you have some ties to IN. We lived in Chesterton, Valpariso area. I attended St Mary's HS in Michigan City, Ball State University in Muncie. Still have a Sister in Valpo.

TeJay

[FIRE UP]

Originally Posted by TeJay

Ray,IN,

More interesting points. The torque to yield (TTY) bolts are torqued into their elastic limit and therefore will not return so must be replaced. They did that so that every bolt would achieve the same clamping forces regardless of all the variables associated with torquing bolts, especially ones like head,intake and manifold. One does have to worry about: lubrication on threads, dirt, thread condition,technicians incompetence, torque wrench and it's accuracy.

As far as reusing cast iron head bolts I guess one can be supper careful but as long as you never get into the elastic limit of the bolt it never seemed to matter. We did hundreds of engines and only broke head or block bolts when a student didn't know/remember left from right.

I guess the IN in your handle means you have some ties to IN. We lived in Chesterton, Valpariso area. I attended St Mary's HS in Michigan City, Ball State University in Muncie. Still have a Sister in Valpo.

TeJay

Hey Tim,
You know, while this is somewhat close to the original topic, I appologise for veering away a bit. One of the MANY side jobs I did while in the career of a fireman was being sort of shade-tree mechanic. I never kept track but, I figure Iv'e got oh, around 100 - 150 engines under my belt for rebuilding. And those include mostly stock car and truck engines, some hi-performance but, no diesels.

In all the time I was doing this "rebuilding" thing, not one of the machine shops that I did my machining with, EVER suggested I replace ANY head, main bearing, rod, or any other BOLTS due to age, over stressed, (may have already been torques several times in that engines particular life) etc.

In all that time, I never had ANY engine come back or, blew apart due to failure of any of those bolts. Now, as stated, I never got into any diesel work.

My wheels are Accuride and, are hub piloted. They use the two-piece flanged lug nuts. They are required to be torqued to 450 ft. lbs. of torque. I have used copper based anti-sieze on them since we purchased this coach, almost five years ago and, those wheels and tires have been off and back on, a few times for various brake inspections, maintenance etc. So far, none of them has passed me up on the freeway.

I use a Proto, 3/4" drive, 4' torque wrench.
Scott

[Scatterbrain]

Originally Posted by FIRE UP

Hey Tim,
You know, while this is somewhat close to the original topic, I appologise for veering away a bit. One of the MANY side jobs I did while in the career of a fireman was being sort of shade-tree mechanic. I never kept track but, I figure Iv'e got oh, around 100 - 150 engines under my belt for rebuilding. And those include mostly stock car and truck engines, some hi-performance but, no diesels.

In all the time I was doing this "rebuilding" thing, not one of the machine shops that I did my machining with, EVER suggested I replace ANY head, main bearing, rod, or any other BOLTS due to age, over stressed, (may have already been torques several times in that engines particular life) etc.

In all that time, I never had ANY engine come back or, blew apart due to failure of any of those bolts. Now, as stated, I never got into any diesel work.
.......
Scott

Were you using TTY bolts? Not everyone uses them. Depending on the era of the machinery you were working on and the manufacturer it's possible that you never encountered one. TTY bolts will have a torque spec that reads like : 114lb-ft + 90*. As you rotate through you can feel the bolt stretching. Their adoption in the industry isn't universal; either via time frame or application.

Beyond that I would point out that just because one didn't come right back to you with a fault didn't mean a fault didn't develop later. The problems may only manifest themselves under certain load conditions or after a certain period of time. Improper wheel torque is the same way. The problems caused by uneven wheel torque aren't going to show up on the first test drive. It may take quite a while for them to develop, depending on the driving conditions.

[TeJay]

Good info FIRE UP. As far as I know there were no TTY bolts being used unless it was on aluminum blocks, heads. And I don't believe they were used when they first went the aluminum route. And no they are not universal but they are used on about all aluminum blocks and heads. To many things can go wrong if they are not used.

They are an extra expense but were employed because of the variables that were not under the control of the manufacturer. So to prevent comebacks and warranty that were not properly fixed the went to the TTY.

We never bought new head bolts for cast iron blocks or heads.

TeJay

[barmcd]

I wasn't aware that TTY bolts were used in engines, mostly I've seen them holding on brake calipers or holding rotors on motorcycle wheels.