Torque Values with Loc-tite

[Porsche_monkey]

Yes, Quicksilver is correct. On assembly machines we program the torque tools to initial torque then angle, to stretch the bolt.

But electronic torque tools have about 100x better control than a human. Ideally you would assemble your motor with an electronic torque tool.

[Gunter]

Friends:
Common sense has to be a part of tightening fasteners.
Example: Porsche calls 96 ft-lbs with lube on the lug nuts meaning: threads AND the convex contact area.
Head studs ~25 ft-lbs with lube.
Rod bolts: Torque with lube.

General practise is: Torque with lube unless specified dry.

Of course, the M6 bolts holding the sheet metal to the engine case are not as important as some of the larger fasteners, so, use common sense.
You can lube them all if you like, or not.

I use anti-seize on just about everything including the bolts on the spring plates or the Allen bolts on the CV's and definately the large nut on the rear bearing!
I am sure that some folks wish that the bolts for the engine mounts had been lubed years ago to prevent the bar from being damaged during engine-removal.

[Peter Zimmermann]

Just a few points. Porsche torque specs are for dry fasteners. When an exception to that exists, that exception is footnoted. For example:

1. Cylinder head nut torque (3.2 liter Carrera): Special instruction #1 - Use only yellow-colored nuts, Special instruction #2 - Lubricate threads of head studs and cylinder head nut bearing surfaces lightly with Optimoly HT (DO NOT use oil!). Basic instruction: Step #1 - Tighten to 15 Nm, Step #2 - Tighten at 1 Nm x 90 degrees +/- 2 degrees.

2. Camshaft bolt torque ('83 SC): Special instruction #1 - Lubricate threads lightly with Optimoly HT (oil may NOT be used). Basic instruction #1 - Torque to 120 Nm.

3. G 50 Differential ring gear bolt torque: Just to be sure that it's done right, Porsche includes this Special instruction for the bolts - "Threads must be dry and free of grease," and the same instruction is given for the threaded holes in the ring gear. Basic instruction #1 - Torque to 165 Nm.

A large number of special instructions are given for the almost endless fasteners used in these beautifully engineered cars, I could go on for pages with examples. The point is that to "put a drop or two of oil on it" is foolish, to not have your click-type torque wrench calibrated at the manufacturers recommendation is equally foolish, and to use anti-seize (silver) "just because" is foolish. Correctly assembled and torqued 911 fasteners, with few exceptions, do not come loose. Sure, Porsche goofed with the 2.7 liter head stud/mag case issue, and pretty much everyone knows that. It's probably common knowledge that a light dab of grease (moly or lithium-based with a satisfactory drip temperature) on the threads of a spark plug works better than any other medium to insure easy removal. It's also probably commonly known that a light dab of copper paste anti-seize in lug nut studs is not a bad thing. In the end, quality tools and quality manuals are the keys to satisfactory long-life repairs. Experience can only be gained by doing; reading and using the manual must be a large part of that process. To do it any other way is...foolish.

[RWebb]

Pete - does it say "dry unless otherwise noted" somewhere in the service manual set?

If so, can you post what page?

[Porsche_monkey]

If nothing else the 'dry' vs 'wet' issue is worth clearing up.

What does Wayne's Engine Rebuilding book say?

[Peter Zimmermann]

Originally Posted by RWebb

Pete - does it say "dry unless otherwise noted" somewhere in the service manual set?

Now that is a good question! I'm not actually sure, but I'll do some reading when time is available (have to have teeth worked on this afternoon - yuck!). I go by what I was taught (father was a mechanical engineer and my P-car apprenticeship was served under two guys who trained at the P-car factory - yeah, the one in Germany!) to always check the manual for special instructions, if not - dry. Basic torque procedure may be a given, but there are many, many exceptions; the best rule is to never throw a blanket over everything, and always look for those special instructions (like the flywheel on a 2.0 911 - all mating surfaces have to be free of grease and oil, as should be the bolt head faces, but the bolt threads should get a drop of oil to facilitate installation).

[rusnak]

I'm not sure that "common knowledge" is all that common.

I did not know for example, that torque wrenches are most accurate in the middle of their range. So these tips and pointers are being soaked up like a sponge on my end. Extremely helpful you guys, so thanks!

Pete, good luck at the dentist. A few questions when you come to....where do you get this copper anti seize paste? And the special instructions...are they included in the factory manuals, or are you referring to factory bulletins that were sent out to the factory supported repair facilities? Can I get these by purchasing the factory manual for my 3.2? Do you guys get your torque wrenches calibrated frequently, and if so, which is the best one to buy? Are torque values more accurate with impact sockets? 1/2 inch sockets? Or can I get accurate readings with my 3/8" garden variety Craftsman sockets? I currently use impact sockets on my 1/2" click wrench to check torque values. But the lower torque numbers are clearly not in the middle of the range, and I may need to buy a smaller torque wrench for things like spark plugs (22 ft lbs), right? And is Moly grease the equivalent of Optimoly HT? I mean where am I going to find that stuff?

Ok, more than 2 questions. I still believe in loctite on some stuff, like the clutch cable adjusting nut which seems so shaky out there on such a wobbly fixture like the mounting hook thing.

[Porsche_monkey]

As a general rule I would always use six point sockets rather than 12 point when torquing, and I would use the torque wrench that was closest to mid-scale. So don't use the top end of the 1/4" torque wrench if that value is mid scale on the 3/8" torque wrench.

[RWebb]

- Let me take a bit of a load off Pete, esp. if he is recovering from a severe case of dentista...

Originally Posted by rusnak

- copper anti seize paste is carried by the dealers and by Pelican. The dealers have the Optimoly HT and others also.
Which is the best torque wrench to buy?
- Long thread on this. DO a search. In fact, you can help others by liking URLs to this one and then hitting the make a wiki button...

Are torque values more accurate with impact sockets?
- no
1/2 inch sockets?
- no; unless you have a really long 3/8 Allen or 3/8 extension and are really stressing the H out of it.

- You DO need to buy a smaller torque wrench for things like spark plugs (22 ft lbs).

Is Moly grease the equivalent of Optimoly HT?
- No!

I still believe in loctite on some stuff, like the clutch cable adjusting nut which seems so shaky out there on such a wobbly fixture like the mounting hook thing.
- at a guess, the flexible cable will absorb most vibration! so it will be less likely to need a locking agent; it uses 2 nuts, one to lock. But will a little Purple Loctite hurt? Nah.

[Peter Zimmermann]

Originally Posted by rusnak

I did not know for example, that torque wrenches are most accurate in the middle of their range.

My 1/2" and 3/8" click-type wrenches are SnapOn (my inch lb wrench is Stahwille). I used to have my 1/2" calibrated by SnapOn from time-to-time because of the large number of transmissions that I did. I also bought SnapOn because, if I remember right, they had the most accurate upper scale (range) units on the market at the time. When my wrench was calibrated it came with a detailed spec sheet, which, of course, I can't find!

Originally Posted by rusnak

....(1) where do you get this copper anti seize paste? (2) And the special instructions...are they included in the factory manuals, or are you referring to factory bulletins that were sent out to the factory supported repair facilities? Can I get these by purchasing the factory manual for my 3.2? (3) Do you guys get your torque wrenches calibrated frequently, and if so, which is the best one to buy? Are torque values more accurate with impact sockets? 1/2 inch sockets? Or can I get accurate readings with my 3/8" garden variety Craftsman sockets? I currently use impact sockets on my 1/2" click wrench to check torque values. But the lower torque numbers are clearly not in the middle of the range, and I may need to buy a smaller torque wrench for things like spark plugs (22 ft lbs), right? And is Moly grease the equivalent of Optimoly HT? I mean where am I going to find that stuff?

1. I bought my last tube from Performance Products. Brand name/number = LubroMoly/LM 508. You might try Pep Boys/AutoZone also.
2. Yes, most special instructions are in the original, or supplement, pages of the manual. Our shop references didn't have much of the basics, Porsche assumed that those pages would only be used by professionals who are "supposed" to know better.
3. During tightening even a cheap socket will stretch to a max point, probably before the torque spec for the fastener is reached. For high-torque fasteners I use thick wall/impact type sockets, and all of my transmission tools are built to specs that probably exceed impact socket design (I've never had a factory transmission tool fail). You should probably have a 3/8" wrench, but I don't see a need for an inch-pound one - the only thing that I use mine for is differential bearing pre-load. I'm not sure about the Optimoly, you might want to try Wurth, or maybe Pep Boys (I use lithium-based Kendall Blue Grease instead).

OK, off to the dentist...

[911pcars]

Besides using sturdy sockets, avoid using extensions as these too will give slightly when torqued.

Sherwood

[dentist90]

Uggh... I live at the dentist's office. Must have done something wrong in a previous life.

[RWebb]

if you are good, you can re-incarnate as a colon surgeon

[RWebb]

I put the how does it _not_ cure in the bottle question to the Loctite tech. staff:

Good question!

The[re] is air in bottle and the plastic is permeable.

Note: Our Anaerobic Products cure in the presence of metal (cast iron, carbon steel, copper, brass, bronze) or the absence of air.
An active metal ( ) is best!

[Peter Zimmermann]

Originally Posted by dentist90

Uggh... I live at the dentist's office. Must have done something wrong in a previous life.

Ugh! is right. I'm scheduled for the 17th - 50/50 chance either a crown or (double-ugh) a root canal... they found a cavity under an old filling.

[Gunter]

If it's a Molar with an old filling, your chances are better than 50/50 for a root canal because they have to drill deeper.
My experience with 2 of those was that, after drilling, a temporary filling was applied and we waited for a few weeks to make sure that it would settle down.
If it still was pressure-sensitive, a root canal was done and a subsequent crown or onlay?
One of mine didn't quiet down, but the other one did.
My understanding is that a lot depends on how deep they have to drill out the cavity.
A bad scenario would be to not do a root canal, get the final onlay and a few weeks later find out that it cannot take the pressure and start all over. Outch!

Root canal was not a bad experience; it's better than a spinal tap!
I cannot imagine how things went before Lanacain.

[rusnak]

did you hear about the proctocologist who used two fingers? He could give you a second opinion.

[Peter Zimmermann]

Originally Posted by rusnak

did you hear about the proctocologist who used two fingers? He could give you a second opinion.

You know, I could have made it through the day without that one !

My dentist is planning exactly what Gunter posted above; remove all of the decay, judge remaining o.e. material to the nerve, then (1) fill it and make a crown, or (2) temp fill it and refer me to a RC specialist. I really do not like my teeth , but at least they're still mine.

[rusnak]

if you end up needing dental implants, you can probably let your dentist know about bolt stretch and torque values. I wonder if they put loctite on the dental post?

[dentist90]

Originally Posted by RWebb

if you are good, you can re-incarnate as a colon surgeon

People often comment that my job is gross. At least I get to work at the input end!