My rear axle broke like that a year ago while doing 65!. After a sharp right bicycle turn I hit a tree saving me from multi rollover disaster. I always use window nets or arm restraints now.

 

I hear ya... the first time this happened to me, I was going over 80mph during a XC race on a long straight and luckily I didn't hit anything or anyone. This last Sunday, I suddenly noticed the backend got all squirrely as I zig-zagged between the trees while running about 20mph or so. Again, got lucky and didn't hit anything. I use window nets too (along with 4 point harnesses and other safety equipment).

 

@Mikeyboy_esq
Out of curiosity what brand of axle and how much are you torqueing them to?

 

What axle manufacturer and what are you torquing them to?

 

OEM axles and I torque them to factory spec. (only use an impact to remove bolts)

 

I torque them to factory spec.

So what are you torquing them to?

 

RZR_Joe,
I'm torquing the castle nut to 180 ft. pounds (which is what my RZR turbo service manual says to do).

 

And that would be your problem most likely. Anything over 120lb/ft is excessive IMO. I know what the manual says and that's why I asked you.

 

Okay. Thanks!

 

No. Mine have been set to spec with torque wrench every time. I did not break it with a wrench.

 

I don't think Joe was implying the axle was broken by the wrench. I think he was referring to the extra stress over time caused by the amount of torque the manual calls for.

 

Every time this issue pops up, the owner claims the castle nuts were torqued to factory spec.(180lbs.) I torque mine to 110lbs. 180 is ridiculous.

 

That’s because the engineers at Polaris probably have a reason for the specifications.

 

Quick question. If they were torqued to 180 from the factory and I had them off for maintenance, and re torqued them to 180 again, are the castle nuts shot if I were to take them off yet again and reinstall at 120lbs?

 

The nuts are not hurt. This is ol' never torque. Use good quality impact, bump the nut till it stops, then bump to align hole, install cotter key, NEW. Done.

There is more than one wrong torque in the manual. Drain plugs is a really big one. Set them at manual spec and never get them loose again.

 

Axle Failure Safety Issue

Axle Failure Brake Failure Safety Issue BRAKE FAILURE CAUSED BY AXLE FAILURE SAFETY FIRST!!! I urge you to check your rig often for this failure point. It is life threatening if you are riding steep terrain, side hills or high speeds. I have never had my rear hubs off until this happen...

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TRE Excessive Axle Nut Torque Causes Failure / Safety Issue!

For those of you who have had your axle break at the threads you already know how dangerous this is. The wheel, hub and brake rotor immediately start working their way off your rig leaving you with no brakes in the process!! My first thread on this scary ride was 1 Oct 2019. Then it happened...

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Axle Nuts Backing Off TRE and RS1

THIS IS THE REASON AXLE NUTS BACK OFF The right rear is backing off first because if you have absolutely any slack in the splines to axle fitment that forward drive torque eventually turns hub slightly which turns the washer and nut slightly in the direction to loosen it. The factory fit is...

www.rzrforums.net

 

The nuts are not shot. The question is if you have damaged the threaded axle causing failure.

 

Mikeyboy_esq, how many miles on axles? Mine had 6200.

 

Currently, I have a little over 1,000 miles on my RZR (almost all of which were racked up in XC races).

 

I guess my nuts are not hurt or shot 🤣🤣 Time will tell if the axel has been damaged, only 1500 miles. I will take them off, grease the bearings a bit and put it back on at around 120. Last time i just followed the book.

 

@Mikeyboy_esq You asked the same question on the Turbo group on Facebook, some interesting answers you received

 

I am not sure there is enough incidence of axles breaking at the threads to determine causality. If all the cars come from factory at 180ft/lbs and that torque is causing stress there should be lots of failures there. Only a few of us on this forum are reporting this.

 

I am not sure there is enough incidence of axles breaking at the threads to determine causality

I think you are correct sir. What I find interesting is it has happened to the person twice. That leads me to believe it's something to do with the torquing process.

 

RZR Joe, you don’t just count the ugga duggas on your Milwaukee?

 

Nah, I use a DeWalt

Since they are electric the correct unit of measure is rat-a-tats

 

I think though that the most likely cause is the nut backing off a little, flattening or breaking the cotter pin. A little play is introduced wheel to hub stressing the axle until it breaks. I don’t think less torque is the solution.

(I meant play hub to axle and carrier)

 

 

When I removed my OEM axles, I was able to break the nuts loose with my Snap On 3/8" electric impact. It is not capable of breaking anything loose at 180 ft/lbs... Maybe 120 ft/lbs on a fresh battery.

 

I think you may have had this happen because the axle has already stretched and starting to weaken/break. Just a matter of time. Lot of people having the issue. Most are abusing the rig and it happens after warranty so they just replace and repeat and never report anything. Doesn't seem to matter who makes the axle, but I'm sure some are better than others. Be nice to see SATV make one with slightly larger threads and additional threads on the nuts for more grip at less torque spec. I don't expect to have any more issues after all the research and testing we did on TRE and RS1. It should never happen.

 

The torque amount is oft discussed. Poo has not backed off on 180, and it's been something like 5 years now, so... I don't know the alloy, so we're not going to be able to tell what the "correct" stretch for that nut is. I can say I'm going to use 155-160 NET moving forward instead if 180 and apply some locktite.

As I'm sure you know, the 180 is a dry thread spec. Locktite recommends a 20% reduction in torque when using their thread locker to correct. Since I want an NET 160 max with a threadlocker, I'm going to set my wrench to 125 and tighten to the next hole. I expect to get an equivalent of 160 or so, and I hope to stop nut creep dead.

FYI, the right side is alleged to be the most common, for we tend to turn more sharply to the right, and the load unload of that turn tends to loosen the nut more (as I recall. Read the many threads on this).

I can't help but note the break is at the thread beginning. Right where the most torque from the nut is being applied. Granted its also where a lot of stress from any other g force presents, but this is the place that takes all that load plus the nut torque.

Finally, If I was experiencing axle breaks at all while I was running at speed I'd insta pull that shit off and put on stronger axles. I don't know enough about it, but I'd lean towards a set of 300M axles from somebody that was carefully heat treating them and then I'd have them cryo'd.

Unless of coorse somebody is making a larger splined hub that accepts Poo wheels and brakes, for that's the best of all possible answers.

 

Pro4driver. I just read your threads. Good stuff. I couldn’t find much posting about this Jan 2020 when I broke mine. And as you see was the right rear.

 

Same thing happened to me on my old wildcat. Held on by caliper. Then installed a rhino axle. Sold machine. Then it happened to the guy who bought it. I also agree 180 seems ridiculous. The cotter should prevent back out. I’d agree with Joe. 120 seems far more reasonable.

 

Axle fatigue causes a lot of problems such as this. The end of the threads is a stress riser that after some time breaks because the stress from use starts a crack and it eventually breaks from riding. Axles with less of an abrupt termination last longer (smoother transitions). Axle material is also a factor. Tight is better than loose. Any amount of torque that keeps the axle tight in the hub is OK. I have never torqued an axle to 180. Run the nut up snug with an impact gun (snug not impacted). Tighten until the cotter pin goes in. This should work fine.

Anything that causes wheel spin and then contact with traction increases stress. Jumping and whoops are a couple things that come to mind. Run the best axles you can afford. Not all axles are stress relieved and have the ductility and strength to hold up. I hope that helps.