TAS003 TORQUE ARM CONVERSION INSTALLATION INSTRUCTIONS
1967-1969 Camaro and Firebird
Please take note before proceeding with this installation:
• This product may interfere with certain exhaust kits. Exhaust crossovers are not
compatible with this torque arm suspension. In some circumstances, it may be necessary
to fabricate a custom exhaust to insure adequate clearance.
• While not necessary, a heavy duty cast aluminum differential cover is recommended with
this kit. Cast covers are more structural in nature than the stamped steel OE unit and
will distribute the load across the differential, further strengthening the assembly.
• A service lift, while not necessary, is recommended for this installation.
TOOLS REQUIRED:
3/8” and ½” drive ratchets 9/16”, ¾” wrenches
3/8”, 9/16”, ¾” and 1-1/8” sockets Rubber mallet
Pry-bar Drill
3/8” Allen wrench Step bit or ½” and ¾” drill bits
Jack stands Hydraulic Jack
Grease gun with synthetic lube Torque wrench
Welder (optional) Plumb bob and tape measure
INSTALLATION:
This installation is the second part of the torque arm conversion process. It is assumed at this
point that the installer has already installed the BMR Torque Arm and Torque Arm crossmember using the appropriate instruction sheets. If you do not have these instruction sheets,
please contact BMR or download them from the BMR website before proceeding with the
following installation instructions.
1. Lift vehicle and support with stands under
the frame, allowing the rear end to hang.
2. Remove the rear wheels/tires.
3. If the vehicle has exhaust installed, remove
it at this time.
4. Remove the rear shocks. Using the OE
shock bolts, bolt the supplied BMR shock
plates over the factory shock holes.
5. In order to remove the rear leaf spring bolts,
it is necessary to remove the fuel tank.
Drain the tank using a drill pump or siphon.
6. Support the tank and then remove the two
mounting nuts using a 9/16” deep socket.
Pull the tank support straps down, allowing the tank to be lowered. (Image 1)
7. Lower the tank far enough to access the fuel lines and electrical connectors. Disconnect
and cap the fuel lines. Lower and remove the fuel tank.
8. Support the rear end with jack stands.
1
(CONTINUED)
9. Using a 3/4” socket, remove the leaf spring U-bolts on the rear end. (Image 2)
NOTE: the image shown has aftermarket traction bars installed. Leaf spring mounts
may appear slightly different in nature.
10. Using a 5/8” socket, loosen and remove the rear leaf spring shackle bolts. Loosen the
upper shackle bolt at the frame and remove the shackles. (Image 3)
11. Using a 9/16” socket, remove the (3) bolts on the front spring mount of each leaf spring.
(Image 4) NOTE: the image shown had aftermarket traction bars installed. Front leaf
spring eye may appear slightly different in nature.
12. Once all bolts are removed, remove the leaf springs, leaving the rear end in its original
position.
13. Once the leaf springs have been removed, loosen the bolts and remove the front spring
pockets. (Image 5)
14. Install the BMR trailing arms into the leaf spring pockets as shown using the provided ½”
x 5” bolts. Thread a stainless washer under the nut then tighten to 80 ft/lbs. (Image 6)
15. Re-install the spring pockets into the body as shown in Image 7. Tighten the 3 spring
pocket bolts to 30 ft/lbs.
2
(CONTINUED)
16. Install the BMR control arm mounts onto the axle using the supplied U-bolts. The open
portion of the mount should face forward as shown in Image 8. Tighten nuts to 90 ft/lbs.
17. Lift and insert the other end of the control arm into the axle brackets on the highest
mounting hole and insert the supplied ½” x
3.25” bolts. This connection should be left
loose until a later step. NOTE: it may be
necessary to adjust the length of the control
arms to match the holes in the control arm
mounts. It may also be necessary to move
the rear end forward or back to line the
mounting holes up. If one trailing arm is
adjusted, duplicate this procedure on the
other arm and verify that they are equal in
length before proceeding to the next step.
18. The next step involves installation of the
shock cross-member. This step can be
performed by one person but is much
simpler with a helper. Have a helper hold
the shock cross-member up into place as
shown in Image 9.
19. Use the fuel tank strap mounting positions
as a reference point to locate the crossmember properly forward to back and to
insure that the cross-member is mounted
square in the body. As shown in Image 10,
measure the distance from the relief in the
trunk pan to the main cross tube of the
cross-member. Vehicle production variance
prevents a “one measurement fits all” figure
3
(CONTINUED)
but the measurements should fall somewhere between 4-3/8” to 4-9/16”. Re position the cross-member until the reading from each strap mount relief is equal and
falls within the range listed above.
20. Once properly
positioned, locate the
provided sheet metal
screws in the
hardware pack. As
shown in Image 11,
screw the crossmember into each
frame rail to hold it
into position for the
upcoming steps.
NOTE: the crossmember should draw
up tight against the
frame rail. Any floor
pan deformations that
prevent the crossmember from fitting
flush against the
frame rail should be
adjusted using a pry-bar or rubber mallet.
21. At this step the cross-member may be welded to the subframe or bolted. If bolting is
preferred, proceed to step 22. If welding is
preferred, remove the cross-member and prep
it for welding by grinding the powdercoat off
at the weld points. Remove all paint,
undercoating and scale from the weld area on
the subframe then re-install the cross-member.
Weld a full 2” bead vertically on each end of
the plate and at least 4 inches of weld
horizontally on each side. Wire brush and
paint the weld area with rust preventive paint.
Proceed to step 28.
22. If bolting the cross-member into place,
position the provided frame reinforcement
plate as shown in Image 12. Mark the frame
at the center of the slot using a grease pencil or paint marker.
23. Center punch the marks on the frame to provide a drill centerline.
4
(CONTINUED)
24. The recommended (and easiest) way to drill through the frame rails is with a step type
drill bit. Using a ½” bit (or step bit) drill through the outer portion of the frame rail as
shown in Image 13. Take extra care to angle the drill correctly before drilling through
the other side of the frame rail. Continue drilling through the frame rail until the bit starts
to appear through the inner bolt holes of the BMR cross-member. In most cases, the
holes in the cross-member will “self-align” the drill bit, forcing the bit to center itself in
the hole.
25. Once both ½” holes are drilled through the sub frame, it is necessary to enlarge the outer
frame holes to ¾” to allow insertion of the provided frame reinforcement inserts. Using
either a ¾” drill bit or a step bit (much easier), enlarge ONLY
rail. (Image 14)
26. Assemble the outer reinforcement plate, frame inserts, and ½” x 3” bolts with stainless
washers as shown in Image 15. Slide the assembly through the subframe until the bolts
protrude through the BMR cross-member on the inside of the frame rail. Thread a nut
and stainless washer onto the exposed portion of the bolts and then tighten to 80 ft/lbs.
27. Duplicate steps 21-26 for the other side of the vehicle.
5
the outer holes in the frame
(CONTINUED)
28. At this point it is necessary to assemble the coil-over shocks. Using Image 16 as a guide,
thread the lower adjusters
onto the shock body and
continue threading until
they are all the way to the
bottom. Place a spring
over the shock and then
insert the upper spring
mount on top of the
spring and over the shock
shaft. Thread the lower
shock adjuster up until
the spring has no more slack and seats squarely on the upper and lower mounts.
Continue tightening by hand until the shock has approximately 1.5” of thread exposed on
the bottom of the shock.
29. Slide the upper mount of the shock into the BMR cross-member making sure the shock
adjustment knobs are facing inward. Insert the supplied ½” x 2.5” bolt. Repeat for the
other side. Thread a stainless washer and nut onto the bolt and tighten to 80 ft/lbs.
30. Assemble the bottom shock mount using the provided 5/8” x 4” bolt and aluminum
mounting spacer. Place a 5/8” small diameter washer on either side of the poly bushings.
Insert the bolt into one of the middle shock mounts located on the control arm mount.
NOTE: it may be necessary to raise or lower the rear end in order to insert the bolt.
(Image 17)
31. Place a large diameter washer over the 5/8” bolt inside the control arm mount and then
thread a nut onto the bolt. Tighten to 80 ft/lbs.
32. Repeat steps 29-31 for the other side.
33. Support the front of the rear end and loosen the large bolts that attach the torque arm to
the rear differential mounting plate using a 1-1/8” socket. (Image 18)
6
(CONTINUED)
34. Once the torque arm bolts have been removed,
install the BMR Watts Link mount as shown
in Image 19. Re-tighten the mounting bolts to
150 ft/lbs.
35. The next few steps involve mounting the
Watts Link. Locate the billet aluminum Watts
pivot, the (2) spacers, reinforcement plate, (2)
3/8” x 3.75” bolts, and a ½” x 4” bolt. Refer
to Image 19 and 20 for a visual representation
of these components. NOTE: If your vehicle
will be setup for a low ride height, choose one
of the lower sets of mounting holes to install
the Watts pivot. For most applications, this is
a good starting point. This mounting point,
along with the outer Watts linkage mounting
points, determines the vehicles rear roll center
(RC) height. Variances in vehicle center-ofgravity (CG) height make multiple mounting
locations necessary for fine tuning RC height.
36. Tighten the center bolt to 80 ft/lbs. and the
smaller outer bolts to 35 ft/lbs.
37. Before mounting the Watts link bars, it is
necessary to load the vehicles suspension.
Allow the weight of the vehicle to sit on the
rear end and bounce the car a few times to
settle the suspension. If the car sits too high
or too low, use the provided spanner wrench at this time to adjust the spring height on the
shocks. If it is not possible to a
the springs enough to achieve the
desired ride height, move the lower
shock mounting hole to a different
location. Once the desired spring
height is established, tighten the jam
collar on the shock
the following step.
38. Using Image 21 as a guide, thread
one of the two Watts link bars onto
the Watts link pivot and mount
other end into the drivers side
mount. The bar should be installed
into whichever mounting hole places the Watts link bar at the most level position while
the suspension is loaded. Insert one of the provided ½” x 3.25” bolts. Thread a stainless
washer and nut over the e
and proceed to
djust
the
xposed thread and tighten to 80 ft/lbs.
7
(CONTINUED)
NOTE: the Watts link pivot should be vertical (straight up and down) with the suspension
loaded. It may be necessary to adjust the rod end in
order to achieve this.
39. Duplicate the previous step for the passenger
side Watts link bar.
40. As shown in Image 22, use a plumb bob to
determine proper axle location. NOTE: it is
not necessary to remove the wheels and tires
to accomplish this, the measurement can also
be taken from the wheel itself. Hold the
plumb bob against each wheel well in the
same position and measure the axle location in
relation to the fender. Adjust the rod ends
until each side is equal while the Watts link
pivot remains vertical (not angled). Once all
adjustments have been made, tighten all mounting bolts and then tighten the rod end jamnuts on the Watts link bars.
41. Except for final setup, the installation is complete. Double-check all mounting bolts for
tightness and inject a few pumps of grease into all of the grease fittings using the supplied
silicone based lube. Re-grease the fittings initially after a few miles and then every other
oil change thereafter.
42. Re-install the fuel tank and plumb the fuel lines.
SETTING UP YOUR NEW TORQUE ARM SUSPENSION
1. Ride Height. The very first thing that should be done is to establish the desired ride
height. Previously the height was determined when the Watts link was setup during the
installation process. Most of the time, this setting will be fine however driving the car
will settle the suspension slightly and best determine if the height will need to be altered.
Drive the car 10-20 miles to insure a consistent ride height and verify suspension travel.
NOTE: the suspension should not bottom out except in extreme road irregularities or
very heavy dips. It is important to make sure the shocks
shaft seal life. If you are out of spring adjustment and the suspension is still bottoming
out, try changing the lower shock mounting locations and re-adjusting the springs. This
will give more shock travel and increase the spring tension. In some circumstances with
heavier vehicles, it may be necessary to increase the spring rate. In this case, please
contact BMR for technical help in selecting proper rates.
2. Trailing Arm Angles. With the final vehicle height determined, check the trailing arm
angles. For proper anti-squat, the trailing arms, when viewed from the side of the car,
should angle upward slightly from rear to front (front mount higher than rear mount). If
they are level or angled oppositely, lower the rear mounting point. This angle helps
determine weight transfer upon acceleration. Each vehicle, depending on front-to-rear
weight distribution will vary slightly and favor a “sweet” spot but a slightly upward angle
of 1-2 degrees generally is optimal.
do not bottom out to insure long
8
(CONTINUED)
3. Driveline angle. Driveline angle should not have changed however, for long u-joint life
and a quieter driveline it is important to make sure. If the angle is more than 2-3 degrees,
refer to the BMR torque arm instructions for the proper adjustment procedure.
4. Shock settings. An entire book could be written on this subject but we will just touch on
the basics. Your QA1 shocks have adjustments for both compression and rebound. It is
important to understand that a shocks job is to control the motions of the spring. For
optimal control, you never want the spring to collapse or extend too fast. Determining
those settings will be different for everybody since vehicle corner weights, desired ride
quality, driving behavior, etc. play a role in finding what is optimal for that individual. It
is generally best to start with softer settings and work your way up. The idea is to keep
the tire firmly planted to the asphalt. Too much of either adjustment will not only create
a harsh ride but will force the tires to bounce and lose traction during aggressive driving.
The following recommendations are very basic and intended for street driving. Begin
with the compression settings at full soft and the rebound settings two clicks from zero.
Drive the car over varying road conditions and work your way up to a setting that feels
firm yet still comfortable without excessive bounce over road irregularities. Once the
rebound is set, begin adjusting the compression until ride quality begins to suffer then
back a click. These settings should provide good all-around handling and ride quality,
further adjustment may be necessary for very aggressive driving habits such as road
course and autocross racing.
5. Roll Center (Watts Link Height). Roll center (RC) works in conjunction with the
vehicles center-of-gravity (CG) height. Front RC also plays a role in determining an
optimal rear RC since too much variance between the two can result in unpredictable and
sudden body roll. Since both of these factors vary from car-to-car, finding the ideal
setting will be different for everyone. The difference between the RC and the CG height
determines the amount of weight shift (body roll) when cornering. The center hole on the
Watts Link mount is a good place to start since it relates to the exact center of the axle. If
the vehicle has been lowered excessively, it may be beneficial to begin in one of the
lower mounting holes. Find a place for testing where you can aggressively drive around
a corner consistently. Try a few settings up and down and choose the one that produces
the least amount of body roll. NOTE: remember to relocate the outer Watts link bars
whenever you change the Watts Link pivot location. These bars should always be as
parallel as possible to minimize the chance for binding in the mount.
6. Alignment. Once all the above settings have been decided, the vehicle should have a 4-
wheel alignment. This will insure that the rear end is square in the chassis.
If additional help is necessary with the installation or setup of this kit, please call BMR
Fabrication at 813-986-9302 or email Tech-help@bmrfabrication.com.
WWW.BMRFABRICATION.COM
This product is an aftermarket accessory and not designed by the vehicles manufacturer for use on this vehicle. As such, buyer
assumes all risk of any damage caused to vehicle/person during installation or use of this product.
9
Loading...