loctite on rod bolts

[bbh03]

Assembled the rods on the crank today. We forgot to apply loctite (red) on the first rod nearest the flywheel. Should I order two new nuts and bolts and redo this one?

[88-diamondblue]

More details on the engine and if the rod bolts are factory or ARP. Wouldn't cost much for peace of mind.

[bbh03]

Factory bolts - I agree with the piece of mind part.

[sand_man]

FWIW, I've heard it's a "NO NO" to do the Loctite trick on the rod bolts. Not trying to open a can of worms here...just what others have told me. I'm using ARP rod bolts in mine, maybe that has something to do with it.

[Eagledriver]

I'm of the camp that you don't use locktite on rod bolts. That being said I don't think it does any harm. I'd just leave it as is.

-Andy

[Wayne 962]

It's a matter of opinion. If it were a 3.2/3.3/3.6, I would say definitely put it on, but you're fine without it. I recommend it for all rod bolts, but there are plenty of people out there who disagree for reasons I don't agree with...

-Wayne

[ChrisBennet]

The factory manual states that the rod nuts should be lubricated
I'm not in the Loctite-on-rod-bolts camp but if you were using Loctite as your "lubricant" and you installed those last two "dry" (without Loctite or oil) the torque or torque angle menthod will not produce the same rod bolt stretch. Time for a do-over for those two IMO.
-Chris

[sand_man]

I agree...I don't think you'll have any issues, but I think you should re-do the ones missing the Loctite. And I wasn't trying to cause you any undue stress - I'm going through that myself...it's just something I thought I should throw out there. As for me, the ARP bolts come with a special lubricant that is to be used on the bolt threads before the nut is torqued - so I'm not really sure how I'd be able to use the Loctite anyway. Good luck!

[Rot 911]

I used ARP's and they specifially say not to use locktite.

[bbh03]

Despite Wayne's comforting words, I think it is worth just doing that rod over. I have to order some other small parts anyway. Thanks all for your opinions!

Brian

[philippeF]

hello Chris
any further informations about the "stretching method" for rod bolts, datas ? i'm going to do it for my 2.7 RS rebuilt...
thanks !
Philippe

[ChrisBennet]

Originally posted by philippeF
hello Chris
any further informations about the "stretching method" for rod bolts, datas ? i'm going to do it for my 2.7 RS rebuilt...
thanks !
Philippe

Hi Philippe,
There isn't a bolt stretch "spec" for the factory rod bolts as far as I know.
(Aftermarket rod bolts like ARP and Raceware can be installed with the torque angle method or the stretch method.)
-Chris

[bbh03]

My local mechanic suggested (although he normally doesn't use threadlocker at all) using a wicking grade of threadlocker that can seep into the already torqued bolt. I saw Loctite Green at AUtozone which is their wicking grade. It stands up to 300 F. According to their product chart, they don't have a red wicking grade - this is what the green stands for. Comments on this?

Brian

[ChrisBennet]

Originally posted by bbh03
My local mechanic suggested (although he normally doesn't use threadlocker at all) using a wicking grade of threadlocker that can seep into the already torqued bolt. I saw Loctite Green at AUtozone which is their wicking grade. It stands up to 300 F. According to their product chart, they don't have a red wicking grade - this is what the green stands for. Comments on this?

Brian

Yes, the St Patrick's Day Edition Loctite is designed for wicking into already assembled fasteners that won't be disassembled.
It probably won't hurt anything.
It is not a "fix" for an improperly torqued fastener though.
-Chris

[bbh03]

I went back over your post and thought you might say that!

[Wayne 962]

Originally posted by bbh03
Despite Wayne's comforting words, I think it is worth just doing that rod over. I have to order some other small parts anyway. Thanks all for your opinions!

Brian

Actually, I didn't read your post completely - I apologize. If the rod bolt didn't have Loctite, and wasn't oiled, then you didn't achieve the proper torque - need to redo...

The Red Loctite is specifically formulated to emulate the oil that is used during the torque process (there's a previous thread where I quoted this information from Loctite's website). So, using Loctite or using oil should give similar stretch on the rod bolts...

-Wayne

[snowman]

Not the first time I have said this. If you understand how a bolt holds things togather, you will understand that locktite is a waste of time and money. The ONLY way to tighten a performance rod bolt is to measure stretch, PERIOD. Any other way, except the factorys torque to yield, ie troque to angle, is a sub optimal way and not worthy of a performance engine. Only problem with the factorys way is you get ONE chance and then have to replace the bolt. ARP is better, but only if you use the stretch method, and SPS with Carillo Rods is the ONLY ultimate way. Ask any racer with a couple of years on him.

If you overdo( over rev the engine) the rod bolt you only have a few hundred cycles before it breaks, with locktite, maybe a few hundred and one, nothing that will save your bacon. Why? because if your have overdone it everythings also very overheated. When locktite is overheated it isn't there anymore. But bottom line is that nothing has unscrewed. The rod bolt is stretched so it is no longer clamping, resulting in a cyclic load on the bolt, causing he bolt to break, not fall out. If the stretched out bolt is strong enough then the rod will hammer until something else breaks. You end up with a broken mess either way.

[bbh03]

I think Wayne and Chris are saying that here threadlocker is a substitute for lubricant on the threads to make the angular torque method more accurate, but I don't want to start an argument here!