read with interest the discussion on bushings, and found that I don't
agree with some of the comments:
first, I've used the hard poly bushings on my race mini for 7 years with
NO inner metal sleeve to form a bearing surface, with absolutely no
problems. The bushes are supposed to work on the specail hardened
surface of the existing trunnion bolts, or whatever. I used the hard
bushings on the inner A-pan of my racing Midget as well, with no inner
metal sleeve, exactly as described by Roger, and have had no problems
at all. So I don't think that a metal sleeve is required, or will serve as an
upgrade. The metal sleeve is primarily used in applications requireing a
distance piece to set the preload on the joint, which is not the case in
the Sprite.
Second, when I installed the hard bushings in the A-pans, I just pushed
them through with a vise and lots of anti-sieze to lubricate. I used
water-pump pliers, gently, on the top-hat section to rotate the bushing
into alignment. I also found that when they were installed in the car, I
needed a hammer to urge the bolts through, BUT a "small" hammer, used
with subtety, did the trick. Important to note that the correct shouldered
bolts must be used along with the correct "washers" (I don't know what
those thick locator-washers are actually called). I also found that the
pans were hard to move initally, particularly at the bottom of their travel
as when installing the springs. I just stood on them after first making
sure that things were in line and I hadn't installed things backwards or
something. Keep in mind this important point - the bushing material is
PLASTIC - in that it deforms under load. It has to be tight when first
installed, and will work itself (not wear itself) into a tight and proper fit.
Keep in mind that the suspension load forces are far higher than even
me standing on the A-pan to force it down, and that tightness denotes
good fit. Loosening things up when new and cold will probably end up
with a too-loose fit when six races old.
Finally, Spitfire upper A-arms use a NYLON bushing with an inner
hardened sleeve as a distance piece. The material (nylon) is different
than the Poly material that we typically used, and the basic design
requires the distance piece. I used these bushings when building my
panhard rod for that reason, and they worked great.
Last comment. These are old cars, that didn't get built with perfect
alignment when new and probably haven't gotten better with age.
When you put these tough poly-urethane bushings in the suspension,
These small and mostly insignificant mis-alignments get magnified. The
suspension, and bushings, are meant to work under the load of a car,
not the load of a hand pushing the arms about, and they will naturally
feel tight, especially when new. The spherical bearing was invented to
deal with the problem of slight mis-alingment, and is better for these jobs
that the poly bushings ever will be, but we don't use them for originallity
reasons, etc. Just make sure that things are in the right way, and relax!
Cheers Brian Evans
67 Cooper S, 61 Midget, both for sale
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