At 10:29 AM 4/17/97 -0400, you wrote:
>I'm in the middle of rebuilding the front suspension(along with the rest
>of the tiger) and have some questions cocerning the front suspension
>workings. I am replacing the upper and lower a-arm bushings and was
>wondering how tight is the fit between the bushing inner sleeve and the
>fulcrum pin. Is it supposed to be a loose fit, snug fit, press fit or
>what? Mine seems to be pretty loose.Also what was the design intent for
>this assembly? Does the inner bushing sleeve rotate on the fulcrum pin?
>or does the rotation occur between the rubber bushing and the inner or
>outer bushing sleeves?
>--
>joe brackin
>War Eagle '80
>joetiger@mindspring.com
The suspension rubber bushings vary in both quality and size
according to manufacture. Typically the best have been made by a company
named Metalistic. They are supposed to be a press fit into the A-Arms on
the OD. This press installation requires some fixturing to avoid crushing
the outer bushing shells or distorting the A-Arm alignment. The inner
tubes should be a slip fit on the fulcrum pins. Typically the rubber has
flowed during the vulcanization process, and you will find some inside the
tubes. This excess should be removed, so that they slip on the pins without
binding. Remember that the lower fulcrum pins are directional for offset
or you will have alignment problems. I prefer to use blue water-resistant
grease on the pins to reduce rusting although they will likely sieze in a
few years anyway.
The factory design requires that the nuts be tightened to bind and lock the
inner tubes to the fulcrum pin. This puts the rubber in "shear". The
A-Arms move with no motion of the metal shells. This is why it is critical
to leave the nuts loose until you have lowered the car and have the weight
on the wheels. If you tighten the A-Arm nut in the full droop position,
You will exceed the "design intent" for the amount of shear in the
bushings. They are supposed to be in neutral shear at rest. I you observe
the assembly you will see that the inner shell is compressed between the
inner beveled washer and the outer washer using the self locking nut.
The A-Arms should be "skip" welded between the tubular bushing shells and
the A-Arm stampings. The "spin" welds originally used are frequent failure
points. The sway bar slots should also be "bridged" and reinforced with a
1/4" steel rod or similar material. The upper A-Arm should also have the
ball joint receiver rings tack welded to the stamping. Again, these are
frequent historical failure points.
Special attention should be paid to the lower fulcrum pins. Many of the
high service Tigers have had problems with these pieces and sudden failures
can occur. There are no guarantees, but a close physical examination and
possibly a magna flux test are in order. If you have damage from previous
replacements, torch gouges, grinding grooves, etc. consider replacing the
pins. Breakage and initial cracking typically occur at the radius between
the 5/8" dia and the flattened 3/4" dia. or at the milled bolt reliefs. If
you happen to have a set of replacement pins with circumfrial radius
reliefs (the attachment reliefs were turned with a lathe) for the bolts, do
not use them, find replacements.
Good luck with your project.
Tom Hall
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