1984-1991 C4 Motor Mount
Put an end to engine vibrations with this 1984-1991 C4 Motor Mount! Broken or deteriorated mounts should be replaced immediately to avoid added strain placed on other mounts and driveline components. This mount has been accurately reproduced using modern manufacturing techniques to provide an incredible durability! Each mount is constructed from the highest quality rubber and steel available.
Properly secure your Corvette's engine to the frame rail bracket on each side. Two mounts are required to fully repair your C4's L83 or L98 engine. This direct replacement mount has been faithfully reproduced for accurate fitment.
- Fits 1984-1991 Corvettes
- Fits L83 and L98 Engines
- Does NOT Fit LT5 Engines
- Fits LH (Driver's) & RH (Passenger's) Side
- Sold Individually
- Two Required
- Direct Replacement
- Rubber & Steel Construction
- Secures Engine to Frame Rail Bracket
- GM # 17984499
How to Check Motor Mounts according to GM:
Raise the engine to remove weight from the mounts and to place a slight tension in the rubber. Observe both mounts while raising engine. If an engine mount exhibits:
- Hard rubber surface covered with check cracks;
- Rubber separated from a metal plate of the mount;
- Rubber split through center, replace the mount.
If there is relative movement between a metal plate of the mount and its attaching points, lower the engine on the mounts and tighten the screws or nuts attaching the mount to the engine, frame, or bracket.
How to replace the LH motor mount according to GM:
- Disconnect battery negative cable.
- Raise vehicle.
- Remove engine mount through bolt.
- Raise engine only enough for sufficient clearance.
- Remove engine mount to block bolts.
- Remove one exhaust manifold shroud screw.
- Remove mount.
- Replace mount to engine and lower engine into place.
- Install retaining bolts and torque to specifications.
- Reverse remaining removal procedures for installation.
How to replace the RH motor mount according to GM:
- Disconnect battery negative cable.
- Raise vehicle.
- Remove engine mount through bolt.
- Disconnect catalytic converter AIR pipe at exhaust manifold.
- Disconnect catalytic converter AIR pipe at exhaust pipe.
- Disconnect AIR pipe at converter.
- Raise engine only enough for sufficient clearance.
- Remove motor mount bolts.
- Remove mount.
- Replace mount to engine and lower engine into place.
Also known under these part numbers: (For reference only)
- 17984499
- 25-113047-1
- 686420085737
- E11906
- M-2899
How to Check Motor Mounts according to GM:
Raise the engine to remove weight from the mounts and to place a slight tension in the rubber. Observe both mounts while raising engine. If an engine mount exhibits:
- Hard rubber surface covered with check cracks;
- Rubber separated from a metal plate of the mount;
- Rubber split through center, replace the mount.
If there is relative movement between a metal plate of the mount and its attaching points, lower the engine on the mounts and tighten the screws or nuts attaching the mount to the engine, frame, or bracket.
How to replace the LH motor mount according to GM:
- Disconnect battery negative cable.
- Raise vehicle.
- Remove engine mount through bolt.
- Raise engine only enough for sufficient clearance.
- Remove engine mount to block bolts.
- Remove one exhaust manifold shroud screw.
- Remove mount.
- Replace mount to engine and lower engine into place.
- Install retaining bolts and torque to specifications.
- Reverse remaining removal procedures for installation.
How to replace the RH motor mount according to GM:
- Disconnect battery negative cable.
- Raise vehicle.
- Remove engine mount through bolt.
- Disconnect catalytic converter AIR pipe at exhaust manifold.
- Disconnect catalytic converter AIR pipe at exhaust pipe.
- Disconnect AIR pipe at converter.
- Raise engine only enough for sufficient clearance.
- Remove motor mount bolts.
- Remove mount.
- Replace mount to engine and lower engine into place.