Allen Nugent wrote:
>
> Jack,
>
> When I went to refit my rebuilt TR7 (Sprint) engine, we found that the
> lockwashers (specified in the manual) on the clutch-to-flywheel screws would
> visibly spread when the specified torque was applied to the screws. So we
> pissed the lockwashers off.
> Allen Nugent
> Graduate School of Biomedical Engineering
> University of New South Wales
> Sydney 2052 Australia
Further to lockwashers, et al: Think about it -- most critical bolts
are grade 8. Surely flywheel bolts are. The princple of lockwashers was
that they were supposed to apply a little spring pressure and to "dig
into" the bottom of the bolt head -- now, that takes some doing on a
bolt as hard as grade 8. Further support for what you say came from a
recent experience I had installing a Tilton aluminum flywheel --
instructions from Tilton caution against using lockwashers, and say to
use red Loctite.
Worse situations are with the so-called lock tabs, especially those
found on British car connecting rods. Ever watch how those suckers twist
when you torque down a rod bolt? Research shows that these locking
devices can actually contribute to fasteners loosening up.
In a separate message, Justin Wagner cautions against throwing away all
lockwashers. He's certainly right. Safety wiring the steering column
universal joint bolts is still a good thing to do. Same with fan bolts.
-- but remember, safety wire does not usually prevent the bolt from
loosening -- it just prevents it from turning far enough to back out. I
use safety wire where that is a consideration.
I must confess that I still use lockwashers in some locations. Old
habits die slowly.
--
uncle jack the carfrek
TR4 Rallye Replica vintage racer
|