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Mon Dec 16, 2013 10:26 am

Would using Locktite throw off torque settings or specs? I’m thinking of using it on my connecting rod studs/nuts. If I do so do I still use the same torque specs? Also the connecting rod nuts have a groove on one end. Does it matter if the groove is up or down when I'm installing the nuts?
Thanx.
-Karl

Mon Dec 16, 2013 10:29 am

Loctite does not affect your torque settings. It's anaerobic, which means, once there's no oxygen, it hardens.

Can't help with your other question.

Mon Dec 16, 2013 10:40 am

I think it will throw off your torque settings or applied torque,it's not a lubricant like what is needed.even oil has a diferent value than the molly lube for torquing.there are many others that are diferent too.if you torque it properly and it's a good fastner it dosent need it on most app's.

Mon Dec 16, 2013 11:41 am

If you're going to use something other than the recommended lube from the rod bolt manufacturer, then you'll need to get a rod bolt stretch gauge to make sure they are torqued properly.

Mon Dec 16, 2013 1:51 pm

Loctite is designed to be used as a lubricant during assemble so you attain the correct torque. It is not intended as a replacement for correct torque/stretch.

Dry/damaged or dirty threads are the main cause of incorrect torque.

Mon Dec 16, 2013 2:09 pm

Agreed........it will affect torque. Look up the difference between dry torque and wet torque.

Mon Dec 16, 2013 2:43 pm

Ok, loktite question seems covered. The nuts should go with the round (not hexagonal) side down, and if you look at the nuts, they should show signs of having been torqued down thusly...

Mon Dec 16, 2013 4:06 pm

Ok - I got the idea of locktite on the rod bolts here.

http://www.thesamba.com/vw/forum/viewtopic.php?t=451260

Are the nuts and studs a one time use application? I guess I need to buy Mr Wilson's rebuild book...

-K

Mon Dec 16, 2013 4:26 pm

Found this:
The following was about the best found at http://pweb.jps.net/~snowbum/torquevalues.htm, which appears to be a BMW motorcycle site:
When threads are clean and dry, and then Loctite is used on them, as a rough guide, Loctite causes about a 15% increase in actual torque (acts as a very mild lubricant). Because of the safety factor of parts strengths and typical usages, the effect of Loctite is usually ignored, as far as torque wrench settings are concerned. This is NOT SO when using antiseize compound...you should, and in many cases (spark plug threads) MUST allow for the change (30% approximately with antiseize compound).

Clearly the Loctite adds some lubricity. How much is dependant on the type of Loctite. IMHO, when using it on small bolting (1/4" and less) you would need to be very careful about your torque values. On larger fasteners, especially with quality high strength bolting, the effect may be negligible. But the safest method when using Loctite may be to make the corrections required for a lighly lubricated fastener.

My Comment: add in the % torque wrenches can be off, I'd ignore the loctite effect.

Mon Dec 16, 2013 4:42 pm

Here's something I find useful: a bolt, or any threaded fastener for that matter, reaches it's maximum torque about 20 degrees before it yields (breaks). So, to achieve maximum torque, simply turn tighten slowly until breakage occurs, then back it up twenty degrees! Simple , yet effective! (':lol:')

Mon Dec 16, 2013 4:52 pm

FreeBug wrote: Ok, loktite question seems covered. The nuts should go with the round (not hexagonal) side down, and if you look at the nuts, they should show signs of having been torqued down thusly...

You seem to be talking about Nyloc nuts, and actually they go on the other way around. If you put them on upside down as you describe they will not torque up correctly and will loosen. The Nyloc works better to stop nuts actually coming loose than to hold torque even when used correctly, but they are good on VW crankcases as they combat oil seepage.

Mon Dec 16, 2013 5:04 pm

You should not need loctite but you could go to the highest torque range for that fastener to offset some added friction. When I torque important stuff down , I always; retorque it after a few hours and once in a while something gets hung up or compresses/stretches and needs to be tighted more. Castle ;for instance, makes a specific product for torquing fasteners. Also, some people claim that oil breaks down loctite which allows the fastener to loosen or maybe they did not get the threads clean enough.

Mon Dec 16, 2013 7:01 pm

burnt clutch wrote: Would using Locktite throw off torque settings or specs? I’m thinking of using it on my connecting rod studs/nuts. If I do so do I still use the same torque specs? Also the connecting rod nuts have a groove on one end. Does it matter if the groove is up or down when I'm installing the nuts?
Thanx.
-Karl

The groove goes toward rod. The groove is for staking the nut in place. Those are old nuts, since that groove was eliminated in newer nuts.
Connecting rod bolts do not tend to loosen, so there is no need to stake or use locking compounds or safety wire or locknuts. Just lube and tighten to spec.

Mon Dec 16, 2013 7:13 pm

Yeah. He's got original nuts. Torque and peen the collar into the tang with a chisel. Also, didn't VW recommend motor oil for their bolts?

Mon Dec 16, 2013 8:18 pm

theKbStockpiler wrote: You should not need loctite but you could go to the highest torque range for that fastener to offset some added friction. When I torque important stuff down , I always; retorque it after a few hours and once in a while something gets hung up or compresses/stretches and needs to be tighted more. Castle ;for instance, makes a specific product for torquing fasteners. Also, some people claim that oil breaks down loctite which allows the fastener to loosen or maybe they did not get the threads clean enough.

Loctite doesn't break down in oil - if you use the right type for the application. Henkel have a bunch of data sheets on their European site that show the reduction in strength for different temperatures and the presence of oil, fuel, etc.

You don't usually use it on rod bolts, as pointed out - the original nuts were tightened then peened. Oil is usually used, but I don't think an appropriate Loctite, such as 457, will do any harm.

Sun May 24, 2015 8:35 pm

What happens if you only used locktite and didn't chisel the nut, is that ok? Some rods don't have a grove to chisel the nut to.

Sun May 24, 2015 11:45 pm

burnt clutch wrote: Would using Locktite throw off torque settings or specs? I’m thinking of using it on my connecting rod studs/nuts. If I do so do I still use the same torque specs?

Loctite 271 (red high strength) was designed to be a good assembly lubricant for fasteners. When using 271, I do not torque any differently than I would otherwise torque with oil for fasteners requiring critical torque values.

The blue medium strength...not nearly as good of a thread lube, but I don't use it on anything that requires an absolutely critical torque to really mater enough to make an adjustment to compensate for its lack of lubricity anyways. Blue is useful as a sealant if threads are in contact with oil...just let it set up for a day before exposing the threads to any oil, and you shouldn't have any leaks.

More than one way to skin a cat. For example, I use 271 for rod nuts, flywheel bolts, and imstalling perimeter studs into cases. Rod nuts and flywheel bolts are critical torque items and can be torqued to factory specifications due to the lubricating properties of 271. Blue medium strength on oil pressure reliefs valve bolts, case perimeter nuts/bolts, etc...stuff that really doesn't need to be glued on and torque values are not so critical. Case perimeter nuts and bolts are a good example of where it really doesn't mater enough to adjust any torque values. Factory specified 14 ft*lbs, but 12 will still hold and 16 probably won't rip anything out, know what I mean? Anyways, hope some of this helps. 8)