Help... BS versus reality?

#11

"Jim Warman" <mechanic (AT) telusplanet (DOT) net> wrote

Quote:

The engineers demand that some select hardware is changed at the time of
repair...

The reasons can be varied... Obviously cotter pins, snap rings, spring
pins would be amongst those items changed... snap rings on a selective
basis as described by these same engineers or if there is any apparent
damage...

Torque to yield bolts....' Nuff said.

Locking nuts... both nylon insert and stover variety... once they have
done their job and then been removed, they are now suspect...

Many bolts are called as replacement items simply because they have sealer
or thread lock applied to them... If you do re-use hardware, follow a rule
of thumb - it should go back in with fresh whatever it had on to begin
with....

Often, we will see fasteners that have torque recommendations much higher
than the bolt size would indicate.... and no advise to indicate that these
are a one time use only... One glaring example are diesel engine fuel
injector hold downs... On the 6.0, this would be an 8mm bolt that gets
torqued to 26 ft/lb where one would expect to see something in the range
of 15 - 20 ft/lb.

Any of these engineers has no control over how bolts will be used or
re-used... signing off on any re-use clauses could well be a career ending
move for an engineer unlucky enough to have the wrong audience...

Common sense should be the order of the day (you will find that some
fasteners are available locally at most any dealer while others have just
never seen any demand to stock) when deciding on whethe to re-use hardware
or not.

FWIW, if the WSM says "remove and discard", Ford pays for the new
fasteners when the repair involved is performed under warranty.

joe (AT) 4hpc (DOT) com> wrote in message
news:48dea602-b57b-43de-9b7e-95fe847420f5 (AT) q2g2000vbr (DOT) googlegroups.com...
How much of the following is BS and how much is real?

From Chilton... Be sure new wheel hub retainer nuts, tie rod end
castellated nuts, hub-to-knuckle retaining bolts, knuckle-to-strut
pinch bolt/nut and inboard halfshaft circlips are available. These
parts lose their torque holding/retention capabilities during removal
and must not be reused.

Years ago, my girlfriend had her back brakes of her Mazda done at a Midas
shop. About 200 miles later, as she was driving, her back driver's side
tire came off (tire, drum, etc). The reason was Midas re-used the the
spindle nut when reinstalling the drum. This nut was what Mazda called in
thier parts list a "crush nut" which is basically a nut with a slightly
different major diameter (the bottom of the inside threads) than the
spindle. The action of installation cut the spindle threads into the crush
nut, thereby locking it when installed. If you loosened or removed the nut,
it had to be thrown away. Very stupid design (or smart if you look at the
fact that they charged $5 a nut at the time and they were a dealer only
item)

The moral of the story is that if the nut is a castle nut and cotter pin
design or anything that has a secondary retension device (hardware), replace
the cotter pin, retaining ring, etc. but the nut is fine. But if the nut is
a self locking type (either nylon or something similar to the above crush
nut) with no other mechanical retension, it is suspect - It's you're ass
riding in the car and for the couple bucks for the new hardware it's
probably worth it.

IYM

#12

On Tue, 14 Apr 2009 08:14:08 -0400, "IYM" <s u N risr (AT) optonline (DOT) net>
wrote:

Quote:

The moral of the story is that if the nut is a castle nut and cotter pin
design or anything that has a secondary retension device (hardware), replace
the cotter pin, retaining ring, etc. but the nut is fine. But if the nut is
a self locking type (either nylon or something similar to the above crush
nut) with no other mechanical retension, it is suspect - It's you're ass
riding in the car and for the couple bucks for the new hardware it's
probably worth it.

IYM

With the "crush nut" if it could be tightened PAST it's initial

location so solid material was over the "keyway" it could be safely
re-used by punching down "virgin" metal into the slot. Otherwise
replacement WAS mandatory.

An apprentice left the cotter key out of an MG one time - the wheel
fell off on ME. That was a ride!!

#13

I will admit that I reuse many of the fasteners. Then again, I have
had to repair many failed fasteners. Used halfshaft clips bent and
jambed inside the tranny. Had to use a sledge hammer to get the shaft
to come out (so much for a core deposit). Ball joint nut, threads
worn from repeated over tightening. During hard bounce, threads let
go and the carter pin sheared, car laying on the ground. I have
removed pinch nuts where the flated metal had already started to tear
from reuse. And your question doesn't cover some of the new "carbon
bolts" that stretch during every tightening. They say to replace
because the part either gets damaged during install or removal. To
reverse your question, if you don't have the experiance to remove the
part without damage and to inspect it for reuse, you need to replace
the part.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Help... BS versus reality?

Ford Vehicles Discussions About Ford Cars (alt.autos.ford)

Re: Help... BS versus reality? - 04-14-2009 , 07:14 AM

Re: Help... BS versus reality? - 04-14-2009 , 12:17 PM

Re: Help... BS versus reality? - 04-15-2009 , 10:48 PM