Wheel nut torque

[David 84 911]

Can someone tell me the right torque for wheel nuts on a 996 4s tracked once per summer ?

[hcoles]

It's not in the owners manual?

[jrbennett]

Correct torque spec for the wheel bolts is 130Nm (96 ft.lbs)

[hcoles]

Originally Posted by jrbennett

Correct torque spec for the wheel bolts is 130Nm (96 ft.lbs)

I think the 911 series has used that for a long time. I have 94 written on my garage wall, adjusted because I lubricate the threads.

[porterdog]

[QUOTE=hcoles;6808603...adjusted...[/QUOTE]

To?

TIA!

[Canada Kev]

Originally Posted by hcoles

I think the 911 series has used that for a long time. I have 94 written on my garage wall, adjusted because I lubricate the threads.

Torque specs automatically assume threads are lubed/not dry. Except for two things (or was it one?) that I can't remember, but they aren't lug nuts.

[FrenchToast]

It's typically not a good idea to lubricate the threads that often, if at all. When you do you can't just use regular WD-40, anti-seeze, etc.

And if you do lubricate the threads, shouldn't you be adjusting your torque spec to a higher setting?

996 uses lug bolts. I would guess they're steel. For track days, sometimes different clubs want 100 ft/lbs on lugnuts, I would say the same for lug bolts but can't say for sure.

Also a good idea to check the calibration of your torque wrench every few years with a known accurate one.

Take care!

[winders]

Originally Posted by FrenchToast

And if you do lubricate the threads, shouldn't you be adjusting your torque spec to a higher setting?

Not higher. The idea behind tightening fasteners is get them to apply x amount of clamping force. That is done by stretching the bolts y amount. It takes more torque to turn a dry fastener than a lubricated fastener. So, you use lower torque with a lubricated fastener to get the same clamping force as with a dry fastener.

Scott

[Canada Kev]

Originally Posted by FrenchToast

It's typically not a good idea to lubricate the threads that often, if at all. When you do you can't just use regular WD-40, anti-seeze, etc.

Actually I lubricate my lug nuts WITH anti-seize. Don't need a lot, just so they have a bit on when threaded. If there's some already there, you don't need more.

[FrenchToast]

Originally Posted by winders

Not higher. The idea behind tightening fasteners is get them to apply x amount of clamping force. That is done by stretching the bolts y amount. It takes more torque to turn a dry fastener than a lubricated fastener. So, you use lower torque with a lubricated fastener to get the same clamping force as with a dry fastener.

Scott

Originally Posted by Canada Kev

Actually I lubricate my lug nuts WITH anti-seize. Don't need a lot, just so they have a bit on when threaded. If there's some already there, you don't need more.

Bringing up an old thread here, but just wanted to acknowledge that I was wrong. Putting anti seize on threads for studs or lug bolts is common practice. And yes, if you torque them to a higher setting with lubrication (higher than what they are torqued to without lubrication) there is definitely the risk of snapping or breaking the bolt.

However, checking torque wrench accuracy is something I recommend.

Take care,

[86 911 Targa]

Originally Posted by Canada Kev

Actually I lubricate my lug nuts WITH anti-seize. Don't need a lot, just so they have a bit on when threaded. If there's some already there, you don't need more.

Anti seize is what I use @96ft/lbs.

Also, use Saran Wrap between the socket & the lug nuts to prevent scratching.

Merry X-Mas to all.......

Gerry

[Peter Zimmermann]

To avoid possible confusion, not all anti-seize is created equal! My shop never used silver/gray anti-seize. We only used Lubro Moly LM 508 Anti Seize Compound. We simply referred to it as Copper Paste, and applied it to every clean lug nut stud (male threads only). It does not affect torque, rather, it insures accurate torquing. Put a thin smear on about the end 10mms of thread and assemble. Torque to 96 lb/ft, or to 94 for earlier models; you will be surprised at how easy the nuts/bolts will be to remove next time the wheels come off!

[HarryD]

Originally Posted by Peter Zimmermann

To avoid possible confusion, not all anti-seize is created equal! My shop never used silver/gray anti-seize. We only used Lubro Moly LM 508 Anti Seize Compound. We simply referred to it as Copper Paste, and applied it to every clean lug nut stud (male threads only). It does not affect torque, rather, it insures accurate torquing. Put a thin smear on about the end 10mms of thread and assemble. Torque to 96 lb/ft, or to 94 for earlier models; you will be surprised at how easy the nuts/bolts will be to remove next time the wheels come off!

Peter:

I am confused. Mr. Weiner has always advised me to use anti-seize (copper based only) only on the shoulders of the lug nuts to prevent them from bonding to the wheels and to leave the threads dry.

I find this troubling as you are both highly rated in my book and with this conflicting advise, I am confused.

[winders]

Originally Posted by Peter Zimmermann

It does not affect torque...

Of course LM 508 affects torque.....it's a lubricant.

[chris_seven]

Originally Posted by winders

Of course LM 508 affects torque.....it's a lubricant.

+ 1

I never use Copper based pastes on Aluminium Wheel Nuts.

Porsche recommend OPTIMOLY TA but I have found this difficult to find so I use a Loctite Silver Anti Seize.


Buy 235092 Loctite Silver Anti-Seize Lubricants from UseEnco

[RichardNew]

Keep in mind that technically a bolt is a spring. Most wheel bolts get stretched from people who install the nuts with an air gun. Once the bolt is stretched it's junk. It's like a spring that's been stretched too far. It will never return to it's original shape.

Here's an article I wrote for Vintage Motorsport magazine. It's in 2 parts.

Richard Newton

[winders]

Originally Posted by RichardNew

Once the bolt is stretched it's junk.

This is not accurate. Once a bolt is stretched beyond its elastic limit it is junk. Bolts that are stretched within the elastic limit are not junk and can be used again.

Scott

[Canada Kev]

Originally Posted by winders

This is not accurate. Once a bolt is stretched beyond its elastic limit it is junk. Bolts that are stretched within the elastic limit are not junk and can be used again.

Scott

Absolutely. Torque specs are designed with that in mind to allow stretch within the elastic limit, but not beyond it. It's that stretch that applies pressure to the threads that keeps the nut/bolt tight.

[dshepp806]

I use exactly what Pete Z shows (very, very minimally) and make application of the spec'd torque within the books,..at 96 ft-lbs. on the 89 Carrera.

Always, this way. Never a problem.

BEST!

Doyle

[Flieger]

You can stretch something beyond yield and still use it. The urban legend (not sure if true or not) is that the Porsche rod bolts and flywheel bolts would preload beyond yield during installation. Though reusing those is not recommended.

When you have a lower grade steel and stress it beyond yield but below ultimate it will work harden and become more brittle, but you can still load it up to the same point again (generally) and it will be ok, and it won't stretch any more because work hardening increases yield strength and decreases ultimate (brittle).

Springs are often "preset" which means they are stretched/crushed beyond yield in order to increase yield strength so that they can endure higher loads during service. This is done by the manufacturer and you need to account for it when winding the wire so you get the correct dimensions afterwards. Torsion bars are also "scragged", hence the left and right markings since you don't want to reverse the strain direction when you have yielded it in one direction.