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Trailing arm studs


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I fitted one of my Quaife hubs today but looking at the nylocs they appear only just to have bitten and don't have any thread poking through which I've always been told is a must--has anyone else experience of this- should I replace these nylocs with the thinner ones to get the threads poking through or?? 

 

Michael 

IMG_20200611_165457.jpg

Edited by michaeldavis39
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As you say I'm not sure the nylock has a purchase on the thread there.

Yes, use thinner ones giving say another 2 mm of protrusion, or if not available thin the nuts yourself with a flap wheel (keep the compression face parallel). There isn't any major pulling forces there mostly just shear so the nut locking doesn't need to be over the top, but definitely needs to be engaged.

Mick Richards

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It looks like the thread is 1 or 2 turns in the Nylon? You can feel that and count when you tighten them.

For me that would be OK - if you tight them up with the correct torque.

Possibly posting this causes a discussion but it is my opinion:

the rule "+ some turns through the nut" is for checklist workers and only a " hope" for correctly done work, it is not a guarantee for a correctly tighted nut.

More than nylon nuts I like Loctite 242

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11 hours ago, michaeldavis39 said:

I fitted one of my Quaife hubs today but looking at the nylocs they appear only just to have bitten and don't have any thread poking through which I've always been told is a must--has anyone else experience of this- should I replace these nylocs with the thinner ones to get the threads poking through or?? 

 

Michael 

IMG_20200611_165457.jpg

Longer studs s/b used along with aerolite nuts. Aerolites have a metal insert instead of nylon as used in the aerospace industry. How good are the threads in the trailing arms as this may be an issue with Aerolites as they have a much heavier grip than nylocs.

Bruce.

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25 minutes ago, astontr6 said:

Longer studs s/b used along with aerolite nuts. Aerolites have a metal insert instead of nylon as used in the aerospace industry. How good are the threads in the trailing arms as this may be an issue with Aerolites as they have a much heavier grip than nylocs.

Bruce.

That's why I DON'T use Aerolites on these studs. The alloy material is feeble and has a small amount of "throat" material (the distance across the thread near the base diameter), we all know it is possible to strip these threads out of the trailing arms when applying the standard low torques. I've never fancied having to overcome the increased torque requirement of a Aerolite nut which may impart a greater turning force onto the stud and overtighten it into the threaded hole and encourage thread stripping. If you've got helicoiled or 3/8" UNC holes this is less likely but as Marco says I'd prefer a normal nut Loctited with 242 onto the stud to avoid that possibility.

Mick Richards 

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Hi Folks,

these are typical light weight aerospace nuts.  K-Nuts

Typically known as K-Nuts  but go by other names also.  Available in 6 point and 12 point.

Very good for holding components in shear and low level tension. Ideal on propshafts.

I would not use on the hubs due to the low torque needed.

 

Roger

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2 hours ago, Motorsport Mickey said:

That's why I DON'T use Aerolites on these studs. The alloy material is feeble and has a small amount of "throat" material (the distance across the thread near the base diameter), we all know it is possible to strip these threads out of the trailing arms when applying the standard low torques. I've never fancied having to overcome the increased torque requirement of a Aerolite nut which may impart a greater turning force onto the stud and overtighten it into the threaded hole and encourage thread stripping. If you've got helicoiled or 3/8" UNC holes this is less likely but as Marco says I'd prefer a normal nut Loctited with 242 onto the stud to avoid that possibility.

Mick Richards 

That's why I mentioned that there may be an issue with Aerolites! Years ago when I had to remove my driveshaft  I was not impressed with the threads and used a go/ no go gauge on them, the no go went straight in? These were all drilled out  and Perma. threaded in 3/8" UNC. Never had a problem since. 

Bruce.

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IMO they look ok to me.

The nylon sits above the top of the nut and is held by the flange around the top which is a mm or two and the studs are visibly through and pulled the nylon up as the nut has registered. So overall you have your 2mm.

These only need 8-10 ft/lbs which not much.

Andy

 

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Well thank you everyone for your input. I removed the hub and cleaned off the copperslip which I had put on the face of backing plate. Then I fitted hub back on with new normal size nylocs and torqued them to 16ftlbs as factory. Then  a classic car mechanic friend checked them and he was  happy that all was well--yes the nyloc does tighten onto the last 2 threads - so I feel much happier now to go onto fitting the other hub. 

 

Michael

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1 hour ago, barkerwilliams said:

Not suggesting just asking

Why not a Stover nut? I am never sure when a Stover is a better, or worse bet than a nylock.

Alan

Names to conjure with...must be years since I've considered a Stover nut...also known as a prevailing torque fastening. From memory the top 3 or 4 threads are "malformed" ie slightly off pitch which means there is a required torque necessary to just wind them on the thread, in this instance with such a low torqueing figure I think they would be worse than an Aerolite for abusing the poor thread form in the alloy trailing arms. 

Mick Richards

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15 hours ago, PodOne said:

These only need 8-10 ft/lbs which not much.

Andy

 

16 ftlbs is the correct torque.

Stuart.

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