Rear Axle Nuts

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SR Racing
Posts: 1205
Joined: June 24th, 2006, 1:58 pm

Rear Axle Nuts

Post by SR Racing »

For 20 plus years, I have had only one axle nut come loose and ruin the splines on the drum. However, it seems I am hearing about a lot of these failures recently.

What I have always done (since my first failure):

Tighten to 325+lbs. Check for the alignment of the cotter pin. If needed, I tightend more till I had alignment. After the first session, I re-checked. (Same process with drums or discs.) (I have a 500lb torque wrench, so I can get pretty close. I suspect part of the problem is people estimating with a breaker bar etc and missing the mark.)

I have used the current seal packs with either the softer shim and the stronger shim, with no problems.

Some people have done this with no shim at all (especially on discs), but I have an opinon on why it should be used, so I typically do.)

This is what I advise my customers. Anyone have another opinion on how the above should be done?

I know most will swear by the Italian or German drums, but I have used TRW's with no problems (as have many others). If axle nut play develops no drum's splines will last for long., so I don't think that is the issue. I have not even seen any breakage on the TRW drums for the last several years (other than in an incident.)
jpetillo
Posts: 759
Joined: August 26th, 2006, 2:54 pm

Re: Rear Axle Nuts

Post by jpetillo »

Jim, Thanks for the insight. Do you know how accurate the torquemeister is? I know it's just ratios, but have you compared using it and then checking the torque with your torque wrench to see if there is any binding or friction that we might need to take into account? John
fvracer27
Posts: 247
Joined: October 25th, 2009, 8:40 pm

Re: Rear Axle Nuts

Post by fvracer27 »

jpetillo wrote:Jim, Thanks for the insight. Do you know how accurate the torquemeister is? I know it's just ratios, but have you compared using it and then checking the torque with your torque wrench to see if there is any binding or friction that we might need to take into account? John

John I had 1 come loose when I was just using a air and they a huge breaker bar to adjust for pin. Now I use the Torquemeister tool and I can do it anywhere with just about any 1/2" driver torque wrench and I have not checked how accurate it is but I can tell you it will get the nut tighter that I can with a air gun and a huge breaker bar. The tool makes life much easier and give me piece of mind. As Jim said it's a good idea to recheck after a session.
Mark Filip
NER #27
Womer EV-3
BLS
Posts: 441
Joined: May 11th, 2011, 7:52 pm

Re: Rear Axle Nuts

Post by BLS »

What I used to do, and planned to do again, is use a long tube and apply a specific weight value at a specific distance. For example, for 325 ft/lbs, apply 110 pounds of force at a distance of 3 feet, or apply 55 pounds at 6 feet (330 ft/lbs). The torque application has to be near horizontal to work correctly (or you would need to calculate each time for the angle). What I have done is calculate the distance for my body weight. So, for 210 pound body weight, I would apply my body weight at 1.5 ft. or 18 inches (slightly more actually). That works, but not as well as hanging two 25 pound weights 6 ft away and adding a slight bit more. I used an old walker jack handle for the extension, which fits over my 3/4" breaker bar. The weights just slide on the breaker bar extension.

Is doing it this way a problem? Not the easiest way... But it doesn't require any special tools.
Barry
Old Zink FV,
'87 Citation
smsazzy
Posts: 703
Joined: June 24th, 2006, 5:56 pm

Re: Rear Axle Nuts

Post by smsazzy »

BLS wrote:What I used to do, and planned to do again, is use a long tube and apply a specific weight value at a specific distance. For example, for 325 ft/lbs, apply 110 pounds of force at a distance of 3 feet, or apply 55 pounds at 6 feet (330 ft/lbs). The torque application has to be near horizontal to work correctly (or you would need to calculate each time for the angle). What I have done is calculate the distance for my body weight. So, for 210 pound body weight, I would apply my body weight at 1.5 ft. or 18 inches (slightly more actually). That works, but not as well as hanging two 25 pound weights 6 ft away and adding a slight bit more. I used an old walker jack handle for the extension, which fits over my 3/4" breaker bar. The weights just slide on the breaker bar extension.

Is doing it this way a problem? Not the easiest way... But it doesn't require any special tools.
Except for a 6 foot bar that is heavy enouogh to hold 50+ pounds without breaking, plus the 50 pounds of weight and a way to safely attach said weight to the bar, but other than that, absolutely no special tools.

8)
Stephen Saslow
FV 09 NWR
brian
Posts: 1348
Joined: June 26th, 2006, 12:31 pm

Re: Rear Axle Nuts

Post by brian »

That's funny Stephen. I use a big cheater bar and bolt a helping hand on the drum. A helping hand is a long bar with a plate that bolts on the drum with wheel studs or bolts and rests on the ground to keep the drum from turning without relying on a second person. Any of the tightening methods mentioned work and just go for it. I have never seen a axle component fail from over tightening. The spacer is used to control the crush on the small o-ring but isn't really needed for our use. It's critical to re-tighten after the first session, especially on new drums. I prefer to use the axle nuts with a flange and run the LRE drums.
The above post is for reference only and your results may vary. This post is not intended to reflect the views or opinions of SCCA and should not be considered an analysis or opinion of the rules written in the GCR.
BLS
Posts: 441
Joined: May 11th, 2011, 7:52 pm

Re: Rear Axle Nuts

Post by BLS »

Except for a 6 foot bar that is heavy enouogh to hold 50+ pounds without breaking, plus the 50 pounds of weight and a way to safely attach said weight to the bar, but other than that, absolutely no special tools.
Doesn't everybody have those already? :lol:

The 6 foot bar is an old walker jack handle, the weights are from an old weight lifting set and just slide over the jackhandle. Improvise, I usually try to use what I have rather than spend dollars. 8)

Of course, more often than not, I just used body weight. Seemed simple enough. I have one of those cheaters I made to keep the drum from turning that I made a Long time ago...
Barry
Old Zink FV,
'87 Citation
tiagosantos
Posts: 389
Joined: June 20th, 2010, 12:10 am

Re: Rear Axle Nuts

Post by tiagosantos »

I had to splurge for the torquemeister. I'd need a 20 foot cheater bar if I had to rely on my body weight ;)

I think we should revert the minimum weight back to 975lbs, by the way!
FV80
Site Admin
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Joined: June 27th, 2006, 9:07 am

Re: Rear Axle Nuts

Post by FV80 »

brian wrote:... I have never seen a axle component fail from over tightening...
Thought I would chime in on this one... I *HAVE* seen issues from overtightening - it will roll the threads in the nut and on the axle. That means the nut will not thread on the axle easily and screws up further torque guesstimates. I had that going for several years before I finally realized what was going on. The axle and nut were still useable, but a real PITA to take off and put on. Now that I've backed off a bit on the amount of torque I apply (again .. a guesstimate), I've had no further problems.

I think I'll go back and update that other hub/axle thread with my "solution".

Steve, FV80
The Racer's Wedge and now a Vortech, FV80
billinstuart
Posts: 201
Joined: July 17th, 2006, 8:53 pm

Re: Rear Axle Nuts

Post by billinstuart »

Mixed emotions on this. Tightening the nut simply squeezes the brake drum tighter, yet it's the splines which prevent the drum from turning on the axle. We've all seen axles happily spinning in a stripped drum..tightening the nut won't help. I've also seen drums squeezed so hard the ends mushroom. OTOH, it's common knowledge if you don't tighten the flywheel gland way over factory specs you have problems.

I suspect it's a combination of lousy broaching of the splines in the drums and crappy cast iron which creates the problems.

Has anyone ever tried pinning the drums? Drill a hole through the drum and the axle and installing a shear pin?
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