Automatic
transmission to TREMEC TKO big block
conversions
When it comes to big blocks a T5 will not
hold up very well unless you use a T5z, and are not
making more than 450hp. In most cases however, it is
cheaper to run a TREMEC TKO
transmission.
When converting from an automatic to a five speed
there are a couple of ways to execute the swap.
- Use the stock big block 3 or 4 speed
bellhousing with a shortened input shaft
TKO, that will bolt direct to the
bellhousing. Or use a standard length
input shaft TKO and use a spacer/adapter
plate. There is a added
benefit to shortening the input shaft, the
driveshaft will remain the same length saving
you time and money by not having to shorten the
driveshaft. However, in early Mustangs the
shifter will be moved further forward, requiring
additional material to be removed from the tunnel
opening.
When using a stock bellhousing, all the stock
clutch linkage can be used. This is
perhaps the least expensive option as fewer
components are changed.
When the stock
linkage is not available, another option is a hydraulic kit. We offer
hydraulic kits that use
either a internal slave throw
out bearing setup or an external style. The kit comes with a
master and all the hardware to connect the
master to the slave. If header clearance is an
issue, and you wish for a smoother movement, a
hydraulic kit is the way to go.
Use a aftermarket scattershield for added
safety or when a stock bellhousing is not
available. All the same linkage options apply as
the stock bellhousing. The aftermarket
scattershields do offer different motor and
transmission bolt pattern combinations that were
never available before. They are heavier however,
as they are made of solid steel and require more
clearance for the larger flange.
Another linkage option is the new Quicktime clutch cable operated big block
scatter shields. We recommend these
scatter shields for those of you wishing to use
our clutch cable kit in your early Mustangs with
big blocks, as
well as, any late model Mustang using a cable
kit. This bellhousing works very well in Factory
Five Cobra kit cars when installing a big block.
It will work with the stock pedal and cable. Call
us for details or to place an order.
Since the TREMEC transmission mounting point
is further back than stock 3-4 speeds, a TREMEC
cross member is needed for early Mustangs. The cross member is
designed for use with the stock early
transmission mount, so don't make the mistake
and purchase a late model T-5 transmission mount
as it will not work.
For 2x4 trucks, moving the stock cross member back
will solve the mounting difference.
In late
model Mustangs, the stock cross member needs to
be moved back on the outer mounts. This can be
done by cutting the weld, sliding the cross
member and re-weld or swap it out with an
auto cross member which has this done
already.
The shifter on a TKO lines up with
the shifter hole in the floor in early Mustang
and Camaro. Just a little of the floor has to be
removed on the front and right side of the
opening. The stock TKO shifter has two
threaded holes to mount almost any kind of shift
lever desired. We offer both stock like
appearance shifter lever, boot and ball. For
those who like the Hurst look of the 60's, there
are several chrome levers to choose from. Hurst
also offers five speed pattern shift balls in
white and black or T-handles found in 69-73
Mustangs.
Be sure to save the automatic
transmission speedometer cable, as it will be
reused. You will, however, need to install a
T5/TKO speedometer driven gear, which are
available in a variety of tooth counts to match
your differential gear and tire combinations.
Installing the new speedometer driven gear is
simple, it requires removing the c-clip and
pulling the old gear off and sliding the new one
on.
Automatics have a neutral safety switch, so
that the car can only be started in park or
neutral. Manual transmissions don't need, the
switch, which must be by-passed or the motor
will not start. On early Mustangs the four-plug
harness sticks out of the firewall above the
master cylinder. Two of the wires control the
reverse lights; the other two control the
neutral safety switch. Splice two of these wires
together and you've bypassed the neutral switch.
The starters from early Fords with automatic
transmissions work just fine in most cases. The
issue is usually the starter snout length. If
you find yours is too long, replace it with a
manual application starter.