steelymatt

iTrader: (1)

How does over-torqueing the wheels result in warped rotors? Don't the wheels spin independently of the rotors?

spirilis

iTrader: (2)

Wheels spin with the rotors, with the caliper/brake pads stationary (so they apply force on the rotor to slow the wheels). I'm not 100% sure why overtorquing the wheels will cause rotor warpage, however I do know if some of the lugnuts are not tightened evenly, it will promote uneven rotor wear/potential "warpage"

raidwolf

iTrader: (4)

just make sure you torque up to 85 lb/ft all around and you shouldn't have any problems.

weltonw

Here's one link that gives a reasonable explanation:

http://www.shotimes.com/brakes/part1.html

I recommend getting yourself a torque wrench so you can verify all lug nuts are evenly tightened to the recommended setting. You can get a basic 1/2" drive wrench for $25 or less.

spirilis

iTrader: (2)

http://www.stoptech.com/whitepapers/...otors_myth.htm

That's a much better explanation as to WHY rotors warp... neither of these sites explain why overtorquing the lugnuts cause the "warpage". If you're worried about it, don't overtorque it--use a torque wrench. I always tighten my lugs to 85 ft/lbs with a cheap Great Neck 1/2"-drive click-type torque wrench from Autozone.

Zero Deuce SE

Torque them in at least 3 steps in a criss-cross pattern. Don't torque each one to 85 from the start. I usually go 30 60 90 ft lbs.

steelymatt

iTrader: (1)

I have a 3/8" drive with a good torque wrench. Do you think that will work. Also, what is the size of our lugs?

Zero Deuce SE

You mean 3/8" drive sockets? I would prefer to use a 1/2" drive socket and torque wrench. Our lug nuts are 21mm. Use a 6 point socket for best results.

spirilis

iTrader: (2)

No, you will need a 1/2" drive torque wrench. Most 3/8" drive torque wrenches I've seen are for smaller torque specifications.

Our lugnuts are 21mm . Go ahead and get a short (~3-6inch) 1/2"-drive extension too (makes it easier, or get a deep-socket 21mm... it's best to have a little bit of clearance to operate the torque wrench)

I usually tighten mine down as tight as I can get it with the wheel still lifted up (maybe ~50-60 ft/lbs to estimate) and then tighten them down to 85 ft/lbs with the tires back on the ground.

steelymatt

iTrader: (1)

Chanks for your help guys!

aussie983

iTrader: (16)

so the correct final torque for 5th gens is 85 ft/lbs, correct?

Zero Deuce SE

The range is from 72-87 ft lbs.

SkoorbMax

Does it REALLY matter that much to use a torque wrench? I have a long handle and have always just rotated my wheels by criss crossing back and forth and going as hard as I can reasonably tighten them by hand...

FWIW I had a hell of a time undoing the lugs on my car after the people at the tire shop put tires on last time. I had to use a breaker bar to unscrew them, and even then it was difficult. If I'd have waited until I had a flat I'd have been like the guy I saw on the side of the road jumping on his tire changing gear

I didn't know you had to burn in pads/rotors really. Those two links both support the idea. Good links

irish44j

iTrader: (38)

[QUOTE=spirilis]No, you will need a 1/2" drive torque wrench. Most 3/8" drive torque wrenches I've seen are for smaller torque specifications.[QUOTE]

indeed...I have a craftsman heavy-duty 3/8" drive torque wrench and it only goes up to 80. But that's close enough. I go to 80 and then give one more push after it pops.....

Zero Deuce SE

It's not critical if you are hand tightening your lug nuts. It's more critical if you let somebody use impact wrenches to tighten them. People have been tightening lugs without torque wrenches since forever. I just happen to be nit picky when it comes to my lugs. I've owned a used car that had impact wrench tightened lugs when I bought it. The front rotors were warped bigtime. I had to stand on the breaker bar to remove them. Even broke one stud on each wheel when I rotated the tires.

spirilis

iTrader: (2)

Yeah, torque wrench isn't necessary however you should get a feel for what "85 ft/lbs" feels like...

I know the strut tower nuts are supposed to be torqued to ~35 ft/lbs. I used a torque wrench on the front strut tower nuts since I could, however the rears were very tricky, therefore I tightened them with my smaller ratchet, sorta approximating what "35 ft/lbs" feels like... I'm pretty sure I got it close enough.

Like charliekilo3 said, the range is 72-87, so it's not that strict...

SkoorbMax

I also broke a stud undoing my wheels last time. It was not from it being too tight, but the guys who had done my tires cross threaded or something

I was thinking in regards to a torque wrench, how can it get a good reading since it doesn't know the socket size? The torque to the point of the ratchet will be the same but since it applies to the inner edge of the socket, that will always change based on the width of the socket--sometimes by a lot...

spirilis

iTrader: (2)

Never heard this argument before, so it sounds like something worth investigating, however I doubt it matters much with respect to tightening lugnuts--85 ft/lbs is a decent amount of force, so no matter if the actual torque on the lugnut is less, it should still fall within the 72-87 range. Besides, Nissan provides this specification, and I'm pretty sure they came to this conclusion under the assumption that you'd use a 21mm socket with a torque wrench. Otherwise, the specification is useless!

Bear in mind that "torque" is not the true measure of tightening, but the clamping force of the bolt/nut threads is the actual measure... "torque" is just an approximate measure under the assumption that if you give the nut XX ft/lbs of torque, you'll get a clamping force of YY <not sure of units>

Zero Deuce SE

The reading is based on using a socket without an extension. Extensions reduce the applied torque to some degree. It happens with impact wrenches also. The longer the extension, the greater the effect. The extension has a twist/flex to it that absorbs some of the applied torque.

spirilis

iTrader: (2)

Interesting... I always use a short extension with mine, maybe I should just buy a 21mm deep-socket and be done with it

Zero Deuce SE

I use a 5 inch extension with mine to give me enough clearance from the body of the car. That's why I torque mine to 90 ft lbs instead of 87 ft lbs. If you try to use a 21mm deep socket, you will most likely hit your knuckles on the car.

hotrod37

The problem is not the amount of torque that is warping the rotors the problem is in the way the nuts are torqued. in order to properly torque the nuts you must go in steps ie 30 60 85 and use a criss cross pattern if you tighten the nuts in a circular pattern and in just one step you are bound to warp the rotors.

Zero Deuce SE

The problem is using an impact wrench to tighten lugs. They cannot control it enough to get 30-XX ft lbs. Even if they use a criss-cross pattern. A ½' drive impact should never be used to install lug nuts IMHO.

hotrod37

I never suggested using a impact wrench! I thought that everyone understood by the fact that i gave three different touque increments that a torque wrench was required.

Zero Deuce SE

I was referring to one of the most common reasons behind warped rotors. That is being tightened with impact wrenches. I don't know of anyone that has ever warped their rotors by hand torquing.

spirilis

iTrader: (2)

I don't think overtorqued lugnuts is the primary reason for rotor warpage anyway. I'm pretty damn sure it's overheating of the rotors and pads and pad material transfer causing Thickness Variation around the rotor:
http://www.stoptech.com/whitepapers/...otors_myth.htm

Hence all the recent jabber about the new BlehmCo Big Brake Kit, which is the cheapest BBK solution for the 5th gen, since it lets you use stock calipers & pads but with 6th gen Maxima rotors.

Zero Deuce SE

I said that it was one of the most common reasons, not the primary reason.

nick778

Are you sure the lugnuts are 21mm? On my 2k3, a 13/16" socket seems to fit better than the 21mm and is a standard size for most all lugnuts.

spirilis

iTrader: (2)

20mm doesn't fit, 21mm fits, 22mm is too big--so yeah, 21mm is the size, albeit I've seen a little "free play" as well. Plus I think at least one of my lugnuts say "METRIC" somewhere on them, so 13/16" wouldn't be the official size, even if it does fit better.