Retrofitting the ERA rear suspension into a pre-575 Chassis
Printable PDF file of this page

Pieces supplied by ERA:

(2) Trailing arm bracket
(2) Nut plate for inside crossmember
(2) Upper pivot tube
(1) Chassis plug for 1 ¼? hole
(1) Brake line bracket

t

Procedure:
  • If installed, remove the old rear suspension and trailing arms completely.
  • Remove the brake line that goes from the master cylinder to the chassis rail.  It will be reused.
  • Remove the old trailing arm mounts on both sides.  Grind the main chassis rails smooth.
  • Remove the old brake line bracket.

Drill the crossmember in front of the rear suspension as indicated.

  • Once the ½" holes are drilled, use a nut plate manually held in place to locate the two 9/64? holes.  Drill through both the nut plate and the crossmember.
  • One side at a time, fish a piece of light welding wire in through the top ½" hole and out the 1 ¼" hole.  Hook the wire through the nut plate from the flat (not the nut) side.
  • Carefully feed the nut plate through the large hole, keeping slight tension on the wire.  When the plate gets into position, screw a ½-13 bolt through the chassis hole into the nut plate.  ?Tweek? the nut plate so that the top hole lines up and snug the bottom bolt.
  • Put a bolt into the top hole.  Tighten both the top and bottom bolts.
  • Secure the plates with two ½? blind rivets.
Weld on the new trailing arm mounts as indicated.

Rear lower trailing arm bracket location

Weld on the new brake line bracket as indicated.

Upper trailing arm tube
  • Locate the upper trailing arm tube on the frame kickup.

  • Trim the fiberglass around the area.

  • Drill a ¾" hole through both sides of the frame, perpendicular to the face of the rail.

  • Remove the paint around the new holes.

  • Insert the tube through the chassis rail so that the outside edge sits 1/8" above the chassis surface.  The smooth end (internally) of the tube goes away from the car?s centerline, the threads are toward the centerline.

  • Carefully MIG weld around the outer edge of the tube on both ends.  If there is any weld bead above the tube end on the outside of the chassis rail, grind it flush with the tube end.

Upper trailing arm mount