...V-8 Engine Cradle Installation...
...Check to be sure everything fits properly, then finish torque the cradle to chassis bolts.
Pre-Installation Cleaning / Detailing...
Rigging Engine/Trans For Installation...
Dropping the Engine / Transmission into Position...
...Transmission Crossmember Installation...
AOD/C4/T-5 Crossmember Install...(RX-7s originally equipped w/ manual trans)
Truss Style Transmission Crossmember Installation...(RX-7s originally equipped w/ automatic trans)
...Re-locating the Front Sway Bar...
...Checking Drivetrain Alignment / Clearances...
Driveshaft...
Although we sell new driveshafts for this application, an existing Ford driveline can be modified by a
driveline shop to fit your converted RX-7. The proper way to get the correct length measurement is to
insert the output yoke all the way into the transmission, then pull it out about 3/4 to 1”. This will insure
that during normal in and out travel, the yoke will not bottom out during normal use. Measure from the
center of the front of the u-joint to the flat face of the pinion flange on the rearend.
The ‘86-’91 model RX-7s use a driveline with very small non-replaceable u-joints. The NA and T-II driveshaft's rear pinion flange use the same pilot diameter, but Mazda used two different bolt patterns...
All the driveshafts we sell include this special flange and large replaceable u-joints on both ends. No
stock Mazda parts are used.
Shifter...
Clutch Linkage...
...Connecting The Back-up Lite Switch...
2....Considerations & Requirements....
4....Engine / Transmission Installation....
5....Exhaust / Throttle Cable / Accessory Drive / Pulleys....
6....Cooling / Fuel Systems....
7....RX-7 Wiring Harness Connector ID and Circuit Locations....
8....Electrical System Modifications By Circuit....
...9/16" wrench
...5/8" wrench
...3/4" wrench
...The Aluminum Engine Spuds go in from the top through the 2 through holes (appx. 1.180” dia., and
about 18” apart) in the front crossmember behind the steering rack. They function to spread the stress
evenly between the two halves of the hollow front crossmember and prevent collapsing.
NOTE: on models w/ Power steering, the steel lines from the control valve to the slave cyl. must be routed
through the lower hole in the left upright of the cradle.
On these applications, the steering rack mounting bolts will need to be temporarily removed to allow installation of the aluminum spud.
...The two 1/4” thick spud washers install from the bottom with the 1/2” x 3” bolts. The bolts go through the
spud washers, spuds, and through the lower legs of the engine cradle. The lockwashers and nuts are
assembled loosely. Install the 7/16” dia. bolt through the center hole in the engine cradle and the existing
center hole in the crossmember and loosely assemble with the lockwasher and nut. Loosely assemble
the 1/2” x 1-1/2” bolts and nuts through the rear strut tabs and the stock engine mount holes in the
chassis.
...Loosely bolt the rubber engine side mounts into place on the side of the engine.
...Remove the sway bar attaching brackets from the chassis and let the bar hang free.
7/16” bolts.....................40 ft/lbs
1/2” bolts.......................50 ft/lbs
(an exception is the front center bolt in the engine cradle. 15 ft/lbs will prevent crushing)
...This is probably your last chance to easily detail those places remote and
inaccessible, so take a quick look around before it’s too late.
...For installation, the engine/trans should be rigged so that they naturally hang
level, or slightly tail down.
...Carefully lower the engine and transmission assembly into place. Line up and install the (2) 7/16x5" bolts that "pin" ihe mounts to the cradle.
Install the flat washers and de-formed thread loc-nuts. Torque these bolts/nuts to 10ft/lbs.
...After the engine/trans are in their approximate position, support the transmission,
with a floor jack or jackstand, with the output shaft centerline about 6-1/4” below the top
of the transmission tunnel.
...Remove the engine hoist and chains.
...14mm wrench
...14mm socket, rachet, and 6" extension
...3/8" allen socket
...9/16" wrench
...9/16" socket and torque wrench
...this crossmember bolts directly to the existing RX-7 transmission crossmember holes,
using the original bolts.
...Remove the shield that covers the fuel lines on the left side/bottom of the
floor pan, where they pass by the rear of the transmission.
...Install and loosely bolt the rubber transmission mount pad onto the transmission.
...Loosely bolt the crossmember onto the rubber trans mount pad.
...Tighten all the installed trans mount and crossmember bolts. Properly positioned, the
crossmember spans the distance between the frame rails, leaving enough room for the fuel and
brake lines. Re-locating the fuel and brake lines is not required.
...Using a 3/8” drill bit, drill holes in the floor pan thru the (6) holes in the ends of
the trans crossmember (2 holes on each end).
...Install the supplied bolt plates from the top side of the floor pan, thru the new
drilled holes.
...From the bottom side of the floor pan, bolt the trans crossmember onto the bolt
plate studs, using the washers and nuts supplied. Tighten the bolts.
...Remove the floor jack (or jack stand) from under the transmission. The
engine/trans should now be resting on it’s own mounts, and supported by the chassis.
...If you plan to keep the front sway bar (drag racers will want to remove it), at minimum it will need to be re-located. The easiest way is to just move it forward on the chassis, using the existing forward holes as the new rear holes, and drilling new front holes in the chassis. This will effectively move the sway bar forward appx 2-1/2", enough for the center part of the sway bar to clear the double sump oil pan.
For moving the end links forward on the control arms...
......install a spacer between the ears of the bracket on the control arm
......using a longer bolt, re-install the link on the front side of the control arm bracket
There is also the option of simply buying a sway bar that is specially made for the FC/5.0 conversion. There is one available from Quickor Engineering, a 1" solid bar made of spring steel material. If you are interested, you can contact Quickor at 503-819-7847.
We have also heard of customers using the stock swaybar from an '92-'99 BMW E36, which has a 5" drop in the middle.
...The properly installed Ford engine is centered in the car. The RX-7’s rear
differential’s pinion flange is offset 3/4” to the right of center. This is normal. The
engine/trans and the rear diff’s pinion centerline should be parallel, but NOT concentric.
If the centerlines were concentric (exactly lined up with each other), the u-joints would
fail prematurely as they need at least slight internal movement to lube properly.
While you are under the car, be sure to double check clearances at the...
....Steering rack / oil pan
....Harmonic balancer / oil pan / sway bar
....Hood / carburetor top etc.
...The assembled driveline & slip yoke can be installed. The (4) pinion flange bolts should be
torqued to 27 ft/lb (Turbo II 43ft/lb). At least 3/8” of clearance should exist between all parts of the
driveline / transmission tunnel.
...NA rears (4) .393 dia holes on a 3.786” bolt circle
...Turbo II (4) .410 dia holes on a 4.120 bolt circle
When building a driveline for your RX-7, it is wise to use replaceable u-joints to keep future
replacement costs down. We have available a special rear driveshaft flange that uses a much
larger/stronger/replaceable u-joint, which bolts directly to your existing pinion flange .
Automatic trans...It is possible to use the stock RX-7 automatic shifter to actuate the Ford C-4/AOD transmissions. Due to
the fact that the RX-7 shift lever is on the passenger side of the transmission and the Ford lever is on the
driver’s side, it is necessary to bend the part of the shifter that connects to the shift rod over to the
driver’s side. Fortunately, this is quite easy to do. It will then be necessary to fabricate a shift rod to
connect the shifter to the trans, also quite easy using hardware store rod stock.
...It is also quite easy to install a Ford floor mounted shifter from most any RWD passenger car.
T-5 Trans...Due to the location of the Ford engine, the T-5 shifter stub comes up about 3” ahead of the stock RX-7.
This dictates either a dog-leg shifter modification or a shifter relocation adapter to move the shift knob to
the origional RX-7 location. These methods are commonly used in Miata/Ford 5.0 conversions as well,
and are not nearly as drastic as the 6” rearward shifter offset used on the Cobra. Because these
modifications are under the shift boot, the origional look of the RX-7 interior is retained.
(manual trans only)It is possible to install a Ford style cable quadrant under the dash of your RX-7 and
retail the Ford cable linkage, but it is much easier to convert your cable actuated clutch to hydraulic
using a “pull” style clutch slave. It requires fabrication of a simple anchor bracket, and the removal of the
cable anchor tab on the bellhousing. It is also necessary to increase the size of the RX-7 clutch master
cylinder to a 1” bore to get sufficient travel to release your Ford clutch.
...to operate the RX-7's back-up lites, Mazda used a transmission mounted SPST switch to complete the circuit.
When the RX-7's engine harness is removed with the rotary engine, part of this circuit is removed as well.
To restore this circuit, a harness extension will need to be added at connector X-04,
a rectangular 6 pole connector (2 rows of 3) located under the hood on the driver's side of the brake master cylinder.
2 of the wires in this connector are for the back-up lite switch. These wires wires are...
...black wire w/ yellow stripe- comes from 7.5a fuse in underdash fusebox.
...red wire w/ green stripe- goes to back-up lites.
Connecting these two wires together w/ a jumper wire will turn on the RX-7's back-up lites when the ignition switch is in the "ignition" and "start" positions.
Routing and connecting these two wires to your new transmission's back-up lite switch will enable the RX-7 back-up lites when "reverse" position of the shifter is selected.