Rebuilding
UCA Even though Ford made
quality parts it
is still a good idea to rebuild the UCA bushing for better
grease-ability and improved
caster. The first thing you will need to do is remove the UCA from the
spindle. The easiest way to do this without damaging the ball
joint is to make a ball joint removal tool out of a couple
3⁄4”
bolts and a 3⁄4” all-thread connector. I
personally made
mine with two pieces of all-thread, two 3⁄4” nuts
and one
all-thread connector. I did this to make a recessed area for
the
ball joint bolt ends to fit into. Once the UCA has been
removed,
it can be disassembled and inspected. As with any auto part
rebuild, inspect all parts being reused and replace any that are
questionable. When rebuilding a UCA it really makes sense to
replace the shafts and ball joints with new parts. The best
source for new "take off" UCA rebuild parts at about half the price of
normal is www.opentrackerracingproducts.com
The next step is to modify the UCA bushing. I
recommend starting with a bushing shaft assembly. Take a cut
off
wheel and cut a grease groove perpendicular to the thread on the
underside of the shaft. I cut the groove into the shaft from
the
end all the way past where the O-ring seats and to a depth just past
the depths of the threads. This is done for two reasons.
First,
it allows grease to get to all the threads and, second, it provides a
grease escape so that when you grease the bushings you don't push the
O-ring out.
The information regarding
cutting grease groves
into
the bushings came from MustangSteve
of
www.mustangsteve.com. Once the improved
grease-ability has
been achieved, our attention can be turned to improving
caster.
Install the pivot shaft, including the cap nuts, in the UCA so that the
shaft is perfectly centered as it was designed to be. Many
measurements and adjustments will need to be made to perfectly center
the bushing shaft. Completely remove the forward cap and,
once it
is free of the UCA, loosen the rear cap just to the point where it
comes loose from the UCA body. At that point, loosen the rear
cap
another 1/3 of a turn further. NOTE: The amount loosened may vary,
1/3 of a
turn is a good starting point.
Reinstall
the cap
and shaft into the UCA body, including the forward cap. This
process should move the shaft forward about .1”, however,
individual
results may vary and you will need to take careful measurements and
make sure the shaft is moved no more than .1”.
NOTE: Moving the shaft more than
.1” can affect
the way the shaft and retaining nuts work together, which could cause
an unsafe condition.
Moving the shaft forward moves the UCA assembly backwards and gives you
more positive caster. Before you make an improved caster
modification, make sure you have enough clearance between the rear zirk
and the shock tower wall. Once the UCA bushing is lined up
where
it needs to be, tighten the cap nuts down to the point where the UCA
travels without binding up, and then tack weld the caps on three side
so they don't back out.
NOTE:
as with any other
welding, the safety of this modification relies on the strength of
these welds, so if you are not confident in your welding skills, have a
certified professional do it.
The
reason for
welding the bushing caps in place rather than tightening them to the
point where they will stay put themselves is because, often times when
the caps are that tight enough to not come loose, it puts the bushings
in a bind and will cause the assembly to squeak and/or cause premature
failure of the assembly. Also, I have found that it
works
best to rebuild both UCA assemblies at the same time so that they can
be positioned bushing shaft end to bushing shaft end to ensure that
they are mirror images of each other and have the same amount of
improved caster adjustment. At this point the UCAs can be
installed making sure the arm goes to the rear of the shock
tower. As with any front end work an an alignment will need to be
done once the car is back on the road.
UCA rebuild
parts
Cutting a
grease groove in the shaft
Prepped for
welding
Prepped for
welding
Rethreading the UCA with new caps
Measuring side to compare shaft offset
UCAs with offset shafts mirrored
Having
the car aligned:
There
are several
things to keep in mind
when having your car aligned. First, factory Ford settings WILL NOT make for a
good handling
car. The original Ford settings were created with tires made
in
the 1960’s in mind and are not the ideal settings to maximize
performance. Second, make sure you trust the alignment
shop. Aligning an early Ford can be very challenging,
especially
with a “shim” type alignment because as you change
either camber or
caster, the other setting is affected. This makes the process
very time consuming and some alignment shops will align the car to
settings easy for them, rather than the setting you
requested. NOTE: for
best
results, have the alignment shop print out a before and after
specification sheet. Third, aligning a classic
Ford,
especially a pre-1967 car, is not an exact process and, due to the
effects that changing either camber or caster have on each other, the
alignment shop will need a set of tolerance specifications to align the
car within. The following is a print out that I take to my
alignment shop every time I have my car aligned.
Please align to these specs
“1960-1966
Mustang and Falcon Performance Alignment with or without UCA drop”.
These specifications are in order of
importance.
1.
NO more
than .25 degrees difference between driver’s side and
passenger’s side.
2. +2.0 to +3.5 degrees caster.
NOTE: for cars with Adjustable strut rods. Please attain as
much
caster as possible using the shims (at least 1.5 to 2.0 degrees), and
then use the adjustable strut rods to increase the caster and
make the
sides the same. Also, please note that the caster difference
between the driver’s side and passenger’s side
needs to have no more
.25 degrees difference prior to the adjustment of the strut rods.
3. -.5 to 0 degrees camber. No positive camber,
please. There is no problem having a slight variation from
driver’s side to passenger’s side to account for
the crown in the road.
4. 1/16" to 1/8” toe in
If you run into any problems attaining these specs, please call me
(your phone number here).
Please align to these specs
“1967-1970
Mustang, Falcon & Cougar Performance Alignment with or without UCA
drop”.
These specifications are in order of
importance.
1.
NO more
than .25 degrees difference between driver’s side and
passenger’s side.
2. +2.0 to +3.5 degrees caster.
3. -.5 to 0 degrees camber. No positive camber,
please. There is no problem having a slight variation from
driver’s side to passenger’s side to account for
the crown in the road.
4. 1/16" to 1/8” toe in
If you run into any problems attaining these specs, please call me
(your phone number here).
Disclaimer on Daze Tech Tips
I am not an expert
in this field. I have performed these modifications myself with very
good results. I am passing along restoration and
performance tips for the purpose of education. If you are
concerned about reliability or safety issues, I do not recommend that
you or any other individual perform these changes or attempt to modify
your cars from stock configuration except under your own
volition. I do not assume nor accept any liability for the
use of
this
information or how it is applied.