Safety wire vs loctite

[blue924.9]

Good morning everyone,

Working on a 630 but this question would apply to almost any fastener really. Main bearing caps are secured with safety wire. I’m wondering if a good loctite would be sufficient or if I should go back together with safety wire. I’ve done some reading on safety wire and it was used when loctite was not around, and it won’t keep a fastener tight per say but prevented the fastener from falling out if it became loose.

Modern truck engines that I have overhauled don’t use safety wire or loctite on main bearings or rod bearings but they also don’t produce the vibrations a 2 cylinder does either.

What are everyone’s thoughts? Want to do it right, I would even loctite and safety wire the bolts if that is the best way to do it

 

[GChief]

Should be OK. That said we still wire Marine Gas Turbines that we work on, but they get a little bit hotter.

 

[rustred]

Good morning everyone,

Working on a 630 but this question would apply to almost any fastener really. Main bearing caps are secured with safety wire. I’m wondering if a good loctite would be sufficient or if I should go back together with safety wire. I’ve done some reading on safety wire and it was used when loctite was not around, and it won’t keep a fastener tight per say but prevented the fastener from falling out if it became loose.

Modern truck engines that I have overhauled don’t use safety wire or loctite on main bearings or rod bearings but they also don’t produce the vibrations a 2 cylinder does either.

What are everyone’s thoughts? Want to do it right, I would even loctite and safety wire the bolts if that is the best way to do it

Safety wire or cotter pins also is used on overhead equipment and at times both is. used on the same bolt. Oil
Drilling rigs for example where there is a lot of vibration. As for an engine I have never actually seen a rod or main bolt come loose after torquing them. The older engines used wire and cotter pins. I would not be scared to leave them out. As for which locktite to use ,.. use the blue stuff not the red. Blue is the removable stuff meaning u can still get the nut off. Red one is far more stronger and at times needs heat to break it loose. My personal facts from experience in this field.

 

[ss55]

Good morning everyone,

Working on a 630 but this question would apply to almost any fastener really. Main bearing caps are secured with safety wire. I’m wondering if a good loctite would be sufficient or if I should go back together with safety wire. I’ve done some reading on safety wire and it was used when loctite was not around, and it won’t keep a fastener tight per say but prevented the fastener from falling out if it became loose.

Modern truck engines that I have overhauled don’t use safety wire or loctite on main bearings or rod bearings but they also don’t produce the vibrations a 2 cylinder does either.

What are everyone’s thoughts? Want to do it right, I would even loctite and safety wire the bolts if that is the best way to do it

Fasteners and assembly technology have evolved a lot in the 65 to 100 years since your two cylinder Deere tractor was designed. Torque to yield plus 90 degrees assembly was not used back then as farmers wanted to reuse bolts rather than pay for new replacement bolts.

If you want to do it right use safety wire. Otherwise the next guy who works on the engine will be wondering what other shortcuts were taken. Loctite should not hurt or help if the bolts are torqued correctly and safety wire is used.

 

[wp6529]

Blue Locktite, like the Frank's Red Hot, I use that sh*t on everything...

 

[Duner Wi]

Here is 2 minute video on safety wire. Done correctly it should work fine.

 

[Duner Wi]

 

[DanielW]

I'd advocate for safety wire (just make sure it's routed properly). But loc-tite for added security wouldn't be a bad thing. Just make sure you get one that's oil-tolerant: I recommend 243 for mid-strength (probably ok for what you're doing) and 263 for permanent. Note that 'oil tolerant' doesn't mean they'll cure in an oily environment, but rather that oil won't degrade them over time. You always have to make sure the threads are clean and free of oil for the initial setting/cure.

I don't have much patience for the off-brands of loc-tite. When I worked at a machine shop rebuilding studio equipment, it was spec'd in most repair contracts that all fasteners had to have appropriate loc-tite, and we did all kinds of testing with various products. Nothing performed as well or as consistently as genuine loc-tite. Usually they would give some adhesion/locking, but the degree of adhesion, prevail torque, and sealing ability (for pneumatic pedestals where many of the fasteners were tapped into the tank) was totally inconsistent except with real loc-tite. And almost none of the generic knock-offs are oil tolerant.

 

[Brian G. NY]

Here is 2 minute video on safety wire. Done correctly it should work fine.

Key Words: "Done correctly". Be sure to study how to do it.

 

[John Deere D]

Should be OK. That said we still wire Marine Gas Turbines that we work on, but they get a little bit hotter.

Good day GChief...
When I read "Marine Gas Turbines" my interest perks up.
May I ask the class of Gas Turbines you are familer with?
My back ground was with the "GE LM Class"...Land & Marine Gas Turbines.
LM2500...LM1500...... LM1600 class Gas Turbines as well as the Rolls Royce "Spey" Gas Turbines.
Also the Allison 501 K
Thanks......

 

[Russ from MN]

That's a good video! I did a little safety wiring when I was working, but most of our equipment didn't fly, or wasn't supposed to, it wasn't very common. We had the twisting pliers available, they sure make it easy to do a good job.

 

[rustred]

Key Words: "Done correctly". Be sure to study how to do it.

yes, the wire must be pulling the bolt in the tightening postion. plus i used to drill all the bolt heads also. and wondered why you would drill a hole in the head of the bolt as that would weaken the bolt ?

 

[GChief]

Good day GChief...
When I read "Marine Gas Turbines" my interest perks up.
May I ask the class of Gas Turbines you are familer with?
My back ground was with the "GE LM Class"...Land & Marine Gas Turbines.
LM2500...LM1500...... LM1600 class Gas Turbines as well as the Rolls Royce "Spey" Gas Turbines.
Also the Allison 501 K
Thanks......

Same as yours, most of my work is on the 501-K34 GTGs. I have only done DFCs on the mains.

 

[Fixingfarmer]

Good morning everyone,

Working on a 630 but this question would apply to almost any fastener really. Main bearing caps are secured with safety wire. I’m wondering if a good loctite would be sufficient or if I should go back together with safety wire. I’ve done some reading on safety wire and it was used when loctite was not around, and it won’t keep a fastener tight per say but prevented the fastener from falling out if it became loose.

Modern truck engines that I have overhauled don’t use safety wire or loctite on main bearings or rod bearings but they also don’t produce the vibrations a 2 cylinder does either.

What are everyone’s thoughts? Want to do it right, I would even loctite and safety wire the bolts if that is the best way to do it

Torque. Cotter pin loctite blue. Loctite is the only optional thing.

To the op it’s true most truck engines use the torque turn method of reaching the torque to yield. What ever you do don’t do that she doesn’t need the 250 plus 2 flats she’s from the early 60s. Grade 8 torque is good enough. Then a bit more till you find the cotter pin hole. Think of it more like the opposite of doing a wheel bearing don’t loosen.

 

[stevieb49829]

One of the things that has not been mentioned is the quality of the fastener steel alloy is better than when your 70 year old engine was manufactured. If you are not replacing the fastener, then adhere to the proceedure that kept it tight when OEM. Today's high performance engines rely on a specified bolt stretch to do the job now. steve

 

[showcrop]

What Steve posted. If you want to do it right. I got this from the most expensive performance engine builder in my area twenty years ago. You still have to do your homework on the fasteners.

 

[37chief]

In the Navy working on aircraft engines, About everything was safety wired, or had a lock nut. Never used Loctite. Stan

 

[Watthour]

Bear in mind that anaerobic adhesives (LocTite, or whatever brand name you prefer) have limitations. I often disassemble "permanent" glued fasteners, or as Permatex/LocTite call them, "non-service removable" fasteners with an application of heat. You'll never see those in a truly critical application, which is why pinning, safety wire, and things like Ringfeder nuts exist.

A crankcase would probably never get hot enough to soften LocTite, until a bearing seizes and that cap is already turning blue. At that point, the whole thing might as well just let go anyway.

 

[John Deere D]

In the Navy working on aircraft engines, About everything was safety wired, or had a lock nut. Never used Loctite. Stan

The GE J-79 (LM1500 Models GB101 & GB 102) were developed when only lock wire was allowed. Engine is in TEST Stand after fresh overhaul.. Liquid propane is used for test runs...
A young lady asking an old guy for some pointers.....J-79 on vertical work platform..

 

[GChief]

^^^ looks very familiar