lug nuts - torque to what?

[Guest scubabike420]

I have a '95 legacy wagon w/ four wheel disc brakes. What should the lug nuts be torqued to?

[Legacy777]

65-75 ft/lbs

 

I do mine to 75

[Subie Gal]

72 is what i torque mine to

 

check your owners manual maybe?

 

Jamie

[Guest scubabike420]

Thanks guys. Unfortunately I don't have an owners manual. I tried changing my rear brake pads today and broke my lug wrench. I got a new lug wrench and still can't budge them. And yes, I know which way losens them. I had a set of new tires put on last week and they obviously didn't torque them correctly.

[tcspeer]

Was it Wal Mart tire shop? They done mine that way one time and I went to Manager, and showed him how tight they were and he told me to buy new lug nut's and bring him the ticket and he would pay for them. Which I didn't do but maybe he got on to the one who done it. I carry a pipe to put over my lug wrench to break them loose, because they nearly always overtighten them at tire shops.

[Nug]

Overtightening on alloy wheels can damage them, so keep this in mind also.

[Setright]

For sure you should replace the nuts, the threads will have been stressed by the excess torque. The actual bolts should be okay, as long as the threads look normal.

 

I do mine to 98Nm like the handbook says. How many pounds is that again??

[frag]

That's 72.28 lbf-ft.

Overtightening can also damage steel wheels and specially when the guy apply full torque to the first nut and then to the others.

Wheel nut tigntening is a lost art in about every tire shop I know. I've even seen a guy removing the tire from the rim without depressurizing first.

[Setright]

Too true, Frag!

 

Let it be known that I torque my lug nuts progressively. Criss-cross off course. 20Nm, 40, 60, 80, 98.

 

Up to 40 the tyre is off the ground, I lower enough it to keep it still, before it supports the car fully. This method is garaunteed to get the wheels centered right, and believe you me, it can make a difference over 100mph...

[SevenSisters]

To get your lug nuts off, try a 1/2" drive breaker bar with the appropriate 6 point socket. If you don't have one, you'll need one anyway later.

A little penetrating oil may help if they are rusty, but remove all traces of it later.

You may also need a little heat on the nuts and a pipe to put over the breaker bar.

 

When you get them off, you have to make a judgement call on how tight they were.

In addition to new lug nuts, consider this:

When you torque the lug nut, you stretch the stud relative to the torque you apply and it wants to pull back. This is what applies the clamping force to hold the wheel on.

If significantly over torqued the first time, it will not be able to pull back as much the next time you torque it and may provide too little clamping force. Also, even at a lower torque, it may snap because it was over extended.

For example, manufacutrers often recommend using new head bolts for just these reasons.

When you do torque your lug nuts with a torque wrench, clean the studs with a wire brush and don't be tempted to lube them. Oil will give a higher stud elongation for a given torque because to nut is easier to turn.

You should be OK, but consider the above.

[gbhrps]

I have a cheap torque wrench that I just use for tightening the lug nuts on my 5 vehicles, and that's it. It cost about $20 CDN at on of those discount tool places and is certainly good enough for the applicaion that I use it for. Would I use it on head bolts on the motor? NO. Its not engineered well enough for that purpose. As well, years ago I had a Vette that the tire jerk over tightened and it warped the rotor. I recall that it was big bucks to repair that misadventure, and since then I either do the wheel nut torquing myself, or stand next to the technician insisting on the proper hand torqued values.

[bratman2]

I had always heard that you are not suppose to use a impact on alloy wheels. Last time I took my truck in to get the wheels rotated the older gentleman that worked at the Cooper tire place I go to stopped the man working on my truck and handed him a ratchet. I had just opened the service door to stop him from using an impact on my alloy wheels.

[SevenSisters]

Well, there go a sales opportunity to sell you a new set of wheels next time you come in. They probably would have told you that the wheels cracked because you hit a chuck hole.

It's good you were watching them. And these are the same guys that want to sell brake jobs and strut replacements.

[Guest scubabike420]

So I finally got a chance to go back to the tire dealer and confront them about over torquing the lug nuts.

 

There's actually more to the story and since I'm one of the few who is actually at work today, I'll give you all the details.

 

I had my car inspected at this particular tire dealer about a month ago. They pulled all four wheels during the inspection. Two weeks go by and I'm on the PA turnpike headed to work. It was a lovely, raining drive. I admit I was following a little too close and had no time to react to a rather large chunk of loose concrete on the road. I turned down the radio and it wasn't long until I heard and felt a thump thump thump in the left rear tire. Lucky for me I had plenty of room to pull of the road. I get out in the pouring ran, open up the hatch, and stand underneath while gathering everything I would need. I step out into the rain and try to loosen the lug nuts before I jack up the car only to realize that I couldn't budge any of them. I was using the standard Subaru lug wrench and didn't have anything to stick on the end for added leverage. So I grabbed the pair of gloves I had in the car for some added padding and proceded to really crank on them. I broke four lose and on the 5th nut I broke the lug wrench. The socket end just split. A truck driver stopped and with his help and tools I was on my way to work with a donut tire in the pouring rain.

 

At work I had a chance to look at the tire which had a hole in the sidewall of course. Wasn't too bad since all four tires barely passed inspection and I was about ready for a new set anyway. So I call around for a good deal and find out that the tire dealer who inspected the car had the best price. I figured that the over torquing issue might get me an additional discount.

 

Once at the tire dealer I ask the counter person what they torque the lug nuts to? He tells me it depends on the car and told me probably in the neighborhood of 85-95 ft-lbs. I show him the broken lug wrench and suggest that they tightened them much more than that during the state inspection. I also pointed out that even at 85-95 ft-lbs, that was way beyond what Subaru recommends. He ends up not charging me for old tire disposal and I end up with a set of tires for a pretty good price.

 

I figured that this was the end of it all, but I got to change the rear brake pads and I can't break loose the lug nuts again. This is when I posted the original message. I decided to cool down a bit before going back to the tire dealer.

 

So New Year's Eve I get a chance to run over to the tire dealer. By this time they know me by name and can tell I'm not very happy. The counter person tells me to wait because the owner/mechanic will be back soon. When he comes back I see him talking to the counter person and then walks outside with a torque wrench and a socket. I walk out and he tells me he'll take care of it. He attaches a 3/4" to 1/2" drive adaptor and a thin walled socket (I have after market wheels) to the torque wrench and procedes to losen the lug nuts. Well wouldn't you know it he snaps his drive adaptor on the first lug nut he tries to losen. I had to hold back the laughter. He didn't move for almost a minute as he starred at the drive adaptor and when he finally turned to me I said "well at least its a Snap On and you can get it replaced". He then decides to take inside where he used an air gun and we check out all the threads.