Castle nuts and torque

This seems so common there should be a rule of thumb about it that I just
don't know yet. You're torquing a castle nut that will, when you're done,
have a pin inserted through it to hold the nut in position, such as on a
rear axle. In general you're going to hit your torque value prior to
arriving at a perfect alignment for the pin. What's the rule? Next tighter
hole or previous/looser hole? Thanks.

Mike

 

If you're talking about the stub axle of a car which uses tapered
rollers, you would back the nut off to avoid overtightening the bearing
and destroying it in a few thousand miles.

But you're probably talking about a motorcycle axle that uses roller
bearings. Properly installed roller bearing sets have spacers in
between the pair of bearings and on either end, and the spacers take
the axial loads, so you can tighten the axle to the max torque without
worrying about hurting the bearings.

But, be sure to spin the wheel after torquing the nut to be sure it
spins free. Motorcycles with overtightening front wheel bearings don't
steer well.

Also, is the head of the axle free to turn, or is it held by a retainer
at the head end?

In the former case, you should be able to *rotate* the axle into a
position where the hole and the nut align at the same time with perfect
torque.

In the latter case, you might need to use a very thin washer under the
nut to get the holes and slots to align at the same time.

 

<boggle> Name one motorcycle that uses roller-bearings in the wheels. I've
never met one. It'd be total overkill.

So, of course, do the more common ball bearings.

But you just said you can't overtighten the bearings?

Absolute bullshit. The required torque will be reached at a
particular position of the nut w.r.t. the threads; any rotation of the
axle as a whole will not affect this relationship.

If you're that anal, yes. My response would be to adjust the nut to
the closest alignment position[1], but I don't recall ever using a torque
wrench on axle nuts...

[1] With the caveat that if that was at the looser position, I'd loosen back
further than that and then snug back up, in case of hysteresis effects due
to friction.

--
Ivan Reid, Electronic & Computer Engineering, ___ CMS Collaboration,
Brunel University. Ivan.Reid@[brunel.ac.uk|cern.ch] Room 40-1-B12, CERN
GSX600F, RG250WD "You Porsche. Me pass!" DoD #484 JKLO#003, 005
WP7# 3000 LC Unit #2368 (tinlc) UKMC#00009 BOTAFOT#16 UKRMMA#7 (Hon)
KotPT -- "for stupidity above and beyond the call of duty".

 

Or maybe they figure we like the "racer" style that the cotter pin gives?

--
Later,
John



'indiana' is a 'nolnn' and 'hoosier' is a 'solkk'. Indiana doesn't solkk.

 

If its an axle nut you are talking about, doing the nut up a little
more so as to get the split pin to line up will be fine! Ive been a
bike qualified motorcycle mechanic for twenty years and never had a
problem yet doing it this way... good luck! Tommo. PS if you want to
get really picky find the correct torque setting for the size of the
axle, do the axle up to that setting and then go to the next split pin
hole.

 

Years ago, ISTR reading that some Harleys used needle roller bearings
and that a tiny amount of sideways play in the wheels was actually
normal.

Can anyone confirm? It seems too bizarre (on both counts) to be true.

 

Thanks all. It's a rear axle on a KZ1000P. The caveat about bearing type
was great and I've been going in the direction of tighter, so I'm doing the
right thing. Thank.s

Mike

 

If the cotter pin *falls* into the hole, it's too small, use the next
larger cotter pin.

I've installed cotter pins by tapping them into the hole lightly with a
small ball peen hammer for decades.

The muffler will sometimes get in the way of the hammer swing, so I
rotate the axle so the cotter pin hole will be horizontal.

Part of the head of the cotter pin will seat down into the castellation
so the cotter pin cannot rotate.

If cotter pins are too long, they should never be cut to length with a
pair of diagonal cutters. This leaves sharp ends and any mechanic who
cuts himself on a shap cotter pin will curse the asshole who installed
it.

Long cotter pins can be trimmed with a screw cutter like you see in the
side of a pair of insulated lug crimpers.

The ends of the cotter pin are properly bent with the hammer, by gentle
tapping. The long side will cross over the end of the axle, the short
side will go down the side of the nut.

A cotter pin installed in this manner will not rotate back and forth,
so it won't fret against the nut.

 

<snip>

Or just use an R clip.

 

They look very racer-ish, but can easily be pushed out of the hole that
they are not designed to fit in. Lynch pins work best if they can be
pushed in so far that the
big end is occupying the hole.

Racer wannabe's will install a Lynch pin to achieve the pukka look of a
"real" racer, and they also believe that the pin will speed up their
wheel changing in the paddock.

Lo, and behold, when they go to quickly change the wheel, the Lynch pin
is *gone*...

So, they look around to see what the raceresque solution to *that*
problem is, and find that the experienced guys have safety-wired the
open end of the Lynch pin, defeating the quick removal feature...

 

*Shrug*

They work for me, although they certainly don't fit everything.

 

BMW

 

Really?

<Examines sig>

Which?

 

/2 through 1984 rear wheel, /6 through R80 front wheel, and all
swingarms up to 1/81
Part # 07 11 9 985 005 17x40x12 tapered roller SKF 30203

 

Well I'm damned. Didn't stop my old RS rear wheel bearings collapsing at
70mph, mind.