# Over tightening axle nut



## DIYguy2000

I just replaced both front wheel bearings last week on my 2006 Impala and tightened both axle nuts with my impact.

I just clued in today that those nuts probably should have been hand torqued. What damage can be done if I leave them as is? Or has the damage already been done?

Do you recommend that I loosen off the nuts and torque them properly? If so, what torque should they be? I found online someone posted 159 ft.lbs. for the previous generation of Impalas, but I wasn't able to find it for the 2006 and up.

Thanks!


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## toolaholic

Depends on how big your impact is. My cordless V18 Milwaukee 0883 is rated at 2200 inch lbs or approx 180 lb ft. While my corded Milwaukee corded 9072 is 300lb ft. If you used cordless I think your fine but corded or air impacts could have it seriously over torqued.


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## DIYguy2000

Just checked into the specs of my impact. It's a Mastercraft 7.5A with a max torque of 240 ft-lbs. I don't know if it is actually capable of what they 'say' it can do, and I also didn't let it keep going for too long. Either way, I set my torque wrench to 159 ft-lbs tonight and tried to tighten the nuts and the wrench clicked right away without any tightening, so it's over the spec of 159 (if that's what it actually is for the 06 impala). I think tomorrow night I'll loosen off the nuts and torque them properly to 159, unless anyone has any objections to this?


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## cjm94

I would re torque them if they are way over tightened they can take out the new bearing in a short time.


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## ukrkoz

I used 1200 lb/f impact set to about 75% power on drive axles. not aware of any problems. I think, you over reacting. those nuts got to be pretty SNUG in there. of course, you used antisieze on them, right?


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## funfool

Going to disagree here. I do not get paid to work on cars. 
Any time I replaced front wheel bearings, I use a big ratchet to tighten the bearings down. Goal is to seat the bearings, then you back off and loosen them just a bit.
You want to be sure you did suck em up all the way so they are seated.
Then you back off just a bit, maybe a 1/4 turn, They will have a cap and a cotter key that is inserted to hold the adjustment you just made with the new bearings.

Once the new bearings are installed and tire back on, grab the tire and grab the top and bottom and try to move it. You want zero play from the bearings here.
If you use a jackhammer to tighten the nut, you will have zero play, but also will wear out the bearings and the race it rides on.

Snugging it up by hand, then back off to insert the cotter pin is all you need.


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## DIYguy2000

ukrkoz said:


> ...of course, you used antisieze on them, right?


I applied anti-seize to the nut before putting it on, so I'm sure some of it got 'lost' on the outer threads of the axle bolt. I wasn't overly liberal putting it on as I wasn't sure if there was such a thing as putting 'too much' on. If I'm going to re-torque them anyways, I can take the nut right off and apply more anti-seize if it should be loaded on.



funfool said:


> ...You want to be sure you did suck em up all the way so they are seated.
> Then you back off just a bit, maybe a 1/4 turn, They will have a cap and a cotter key that is inserted to hold the adjustment you just made with the new bearings.
> 
> Snugging it up by hand, then back off to insert the cotter pin is all you need.


My axle nut isn't 'crowned' and there's no hole for a cotter pin. Is this something that maybe certain manufacturers do?

Someone else also recommended torquing them to spec, loosening them a 1/4 turn, then re-torque them again to spec. Not sure of the reason, maybe just to be sure they're torqued properly?

I definitely don't want to have to replace these bearings again in the near future. I replaced the originals about a year and a half ago (cheap Canadian Tire 'Certified' brand) and they both failed at the same time. These ones are Moog brand, so I'm hoping they're slightly better.


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## SeniorSitizen

Would you get a warm fuzzy feeling about paying a GM dealer their rates if the mechanic said I always just tighten them until it feels right or I used my impact just a little or a buddy told me or I think yada, yada, yada*?* Probably not*.* So I recommend searching for the correct information from the manual for that vehicle until you find it and then DIY, you'll feel better*.*


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## Marty1Mc

funfool said:


> Going to disagree here. I do not get paid to work on cars.
> Any time I replaced front wheel bearings, I use a big ratchet to tighten the bearings down. Goal is to seat the bearings, then you back off and loosen them just a bit.
> You want to be sure you did suck em up all the way so they are seated.
> Then you back off just a bit, maybe a 1/4 turn, They will have a cap and a cotter key that is inserted to hold the adjustment you just made with the new bearings.
> 
> Once the new bearings are installed and tire back on, grab the tire and grab the top and bottom and try to move it. You want zero play from the bearings here.
> If you use a jackhammer to tighten the nut, you will have zero play, but also will wear out the bearings and the race it rides on.
> 
> Snugging it up by hand, then back off to insert the cotter pin is all you need.


There are two types of bearings. This procedure only addresses the removable type. 

Many cars today, and all FWD cars don't use this type of bearing, but use a much larger sealed bearing. The bearings are pressed into the hub and cannot be set by tightening the nut. For this type, the nut needs to be torqued, usually 180 ft/lbs, which is way above the torque used for the removable bearings.


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## Mort

I'd just loosen it and torque to spec, it'll put your mind at ease. It is harder on the bearings if they're hammered on way too hard.

I also wouldn't recommend anti-seize. It's been shown to reduce the clamping pressure when it is on the threads of a stud. In effect, your torque wrench will show that there is 159 lb/ft of torque on the nut (rotational force), but your clamping pressure (compressive force) will not be up to spec. According to the Tire Industry of America, the best way to get maximum clamping pressure is to have completely clean threads, preferably a new nut, and a drop or two of motor oil on the threads.


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## funfool

Code:


My axle nut isn't 'crowned' and there's no hole for a cotter pin.  Is this something that maybe certain manufacturers do?

No, my 1965 impalla had this :whistling2:
I should know better that things are always evolving, built differently. Sometimes better and sometimes not.
I still drive older vehicles so they are easier for me to work on.
So is obvious, I am not familiar with the changes on your 2006 model.

Someone mentioned this style of bearing, torque could be as high as 180 ft pounds.
I understand this style, on my cj5 was a rear end bearing was 250 ft pounds.
That was a challenge.

As others suggested, find the correct torque specs, A quick search shows me they are 118 to 160 ft pounds for 2001 - 2007 impala.
Seems like a big variation to me, suppose I would shoot for something in the middle.
So last night I was worried you over tighten them, now depending on your air gun, not tight enough.


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## polarzak

funfool said:


> Code:
> 
> 
> My axle nut isn't 'crowned' and there's no hole for a cotter pin.  Is this something that maybe certain manufacturers do?
> 
> No, my 1965 impalla had this :whistling2:
> I should know better that things are always evolving, built differently. Sometimes better and sometimes not.
> I still drive older vehicles so they are easier for me to work on.
> So is obvious, I am not familiar with the changes on your 2006 model.
> 
> Someone mentioned this style of bearing, torque could be as high as 180 ft pounds.
> I understand this style, on my cj5 was a rear end bearing was 250 ft pounds.
> That was a challenge.
> 
> As others suggested, find the correct torque specs, A quick search shows me they are 118 to 160 ft pounds for 2001 - 2007 impala.
> Seems like a big variation to me, suppose I would shoot for something in the middle.
> So last night I was worried you over tighten them, now depending on your air gun, not tight enough.


funfool, When I read your first reply, I knew you must be an old guy like me. I remember packing hub bearings, tightening them, and backing off 'tll there was just a hair of looseness. Replacing new hub bearings is so much more clinical today, buy the part, and bolt it in. Did one on my daughter's car, and it is just no fun not having to put that dry bearing in your hand and packing in grease, and placing with a castle nut. 
To the original poster... an air gun is only used to remove fasteners, in my opinion... a ratchet and THEN a torque wrench is used to put them back on. (Yes, they use them at the factory installation specifically for a particular purpose). No idea what my compressor puts out, but it is never used for tightening a fastener. This from a suit and tie guy, not a licensed mechanic.


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