New lock-nut system

[Lyle O]

Check out this new (well, at least it is new to me) way to secure nuts on bolts (from Kato Fastening). Seems really clever, easy, and effective. Can think of lots of applications (for example, high temp areas where conventional nylon locknuts will melt).

I am not affiliated in any way, but it seemed too cool not to mention...

https://www.katofastening.com/lockone.html

FWIW

[jac1976]

Perhaps on non-castellated tie rods?

[HarryD]

Looks expensive. I would think these Nord Lock washers would be less expensive. https://www.mcmaster.com/nord-lock-washers

[Harpo]

I can't speak to the price but it is a very effective lock mechanism. I tested it at work and I'm impressed. Obviously not necessarily for all joints. I installed this at the same time as the nut. I need to test this on a Yonkers machine so I have quantitative data

[1QuickS]

It requires a thread extension past the nut that would typically require longer bolt to incorporate its use. Normal thread extension past the nut is one thread and this device requires three threads. Vibration test looks impressive!

I had the opportunity to see NORD lock washers in use on the driveshafts of a M113 armored personnel carrier years ago, they failed at the notch in the ramp due to the stress riser there under compressive load due to clamping force and vibration during use.

[Harpo]

Agreed a longer bolt my be necessary

[911pcars]

Might be a good application for rod bolts as extra insurance. Instead of stainless steel, Ti would be a lightweight preference in this application.

[HarryD]

Originally Posted by 1QuickS

It requires a thread extension past the nut that would typically require longer bolt to incorporate its use. Normal thread extension past the nut is one thread and this device requires three threads. Vibration test looks impressive!

I had the opportunity to see NORD lock washers in use on the driveshafts of a M113 armored personnel carrier years ago, they failed at the notch in the ramp due to the stress riser there under compressive load due to clamping force and vibration during use.

Good to know.

[winders]

Originally Posted by 911pcars

Might be a good application for rod bolts as extra insurance. Instead of stainless steel, Ti would be a lightweight preference in this application.

I don’t see how these would help. It’s clamping pressure that keeps rods working right. Lose the clamping pressure and failure is coming rather quickly. This new locking system won’t keep nuts from backing out enough to lose clamping pressure.

[911pcars]

Originally Posted by winders

I don’t see how these would help. It’s clamping pressure that keeps rods working right. Lose the clamping pressure and failure is coming rather quickly. This new locking system won’t keep nuts from backing out enough to lose clamping pressure.

Understood, but perhaps a rod knock might provide some warning sign instead of a loud bang if the con rod fails altogether.

[Marc Bixen]

???? That ain't gonna help s--t on a rod bolt/nut. You need to understand the stress a rod is going through plus at say 6,000 rpm, that's one hundred revolutions PER SECOND. If the nut loosens at all, it's almost instantaneous, catastrophic destruction. Ain't gonna help.

[911pcars]

Originally Posted by Marc Bixen

???? That ain't gonna help s--t on a rod bolt/nut. You need to understand the stress a rod is going through plus at say 6,000 rpm, that's one hundred revolutions PER SECOND. If the nut loosens at all, it's almost instantaneous, catastrophic destruction. Ain't gonna help.

Marc,
Your math is right on. However, at 3000 rpm, it's only 50 revs/second Still plenty fast.

Catastrophic damage like a broken rod bolt doesn't always occur. Instead of the rod bolt breaking, what if the nut just loosens a bit or the rod bearing spins creating more clearance? I guess I'm just an eternal optimist.

Sherwood

[Marc Bixen]

You've got seconds to live. Again, it all happens quite fast. Rod knock usually occurs when bearing wear becomes excessive, maybe a few thousandths, but everything is still tight. I remember a machine shop many years ago tell me," if you get anything wrong in an engine build, you'll find out immediately". "They usually don't even get off the lift." Words of experience, but an experience I've never had. Rebuilds are expensive, mistakes are VERY expensive.

[911pcars]

Stop Marc, You're scaring the xxxxx out of me.

Appreciate your words of wisdom though.

S

[Walt Fricke]

The only way a properly torqued rod nut could back off is if the bolt is stretched beyond its yield point into the plastic zone. With the clamping pressure of the nut against the rod body gone, the nut is basically loose, and so could spin off. I'm dubious that things would get that far without the bearing first spinning, followed by a lot of heat, and probably a big bang.

The way to build some insurance into a stock motor is to use ARP or Raceware extra strong rod bolts, properly fastened.

If the nut is properly tightened, it isn't going to come off absent some other disastrous event.

I suppose you could use something like this on the valve covers, because you don't want too much pressure on the gasket. But I routinely reuse the Nylocs, and they don't come off as it is. My guess is that the nylon insert is more there to stop oil from wicking out the threads than as an anti-rotation device. Just a guess.

Some swear by Nordlocs for CV bolts - but lots of guys have never had one come loose, at least not if retorqued after the car had been driven some after the CVs were put back on, just as a precaution.

So what nuts (or bolts) do you guys find coming loose all by themselves?

[911pcars]

"So what nuts (or bolts) do you guys find coming loose all by themselves? "

Mostly the ones that weren't properly tightened in the first place. How's that? Some of us could probably use a few boxes of those failsafe nuts.

[bkreigsr]

What - nobody uses PAL nuts on rod bolts anymore?
Bill K

[Geneman]

i have been using the nord-locks on my axel bolts to trans flanges for years now... along with never re-using a bolt after its torqued.

based on the failure noted by iquicks above, should something else be used?


)the damage i have seen in pics from 911 axel/flange bolts failing is catastrophioc..)

[Marc Bixen]

Sorry 911P... Sometimes I can be a little too "honest".

[jjeffries]

Originally Posted by Marc Bixen

Sorry 911P... Sometimes I can be a little too "honest".

That's a good way of separating the men from the boys among us mechanical types and probably the thing which enabled me to be a service manager for quite a few years. Not that I was like the cigar-chomping crew chief on Bah Bah Blacksheep, but I knew we had to maintain a BS-Free workshop!