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MM Racing Rear Upper Shock Mount for MMD-RCxxxx series MM shocks

MM Racing Rear Upper Shock Mount for MMD-RCxxxx series MM shocks
Actual product may differ from photo.
  • MM Racing Rear Upper Shock Mount for MMD-RCxxxx series MM shocks

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$99.00

  • Part # MMSM-12

Description 

MM Racing Upper Shock Mount Kit
Fits
  • Fits MMCO-23 with Black MMD-RC1xxx Series MM shocks
  • Fits MMCO-21 with Yellow MMD-RC0xxx Series MM shocks

Securely mounts one MMD-RCxxxx series shock top to the chassis with a spherical bearing. Eliminating the vertical deflection allowed by standard rubber upper bushings increases the overall damping effectiveness.

The spherical bearing's freedom of movement eliminates side loading on the shock shaft caused by rubber bushings. That loading increases friction that reduces the effectiveness of the shock valving.

The spherical bearing also allows instantaneous damping from the shock when the suspension moves. With a compliant upper mount such as rubber, the mount deflects vertically before the shock moves, so no damping occurs over smaller bumps. Removing this rubber increases damping effectiveness over small road bumps, significantly reducing the chance of damaging wheel hop.

This MM mount performs the same as a spherical rod end, but does not reduce precious bump travel as happens when fitting a rod end under the shock tower. Because there is increased noise transmitted into the passenger compartment, and installation of the shock mount is not easily reversible, this product is recommended only for race cars. Not for use with IRS due to reduction in droop travel.

Note
  • 1 kit fits 1 shock. 2 kits required per car.
  • Fits MMD-RCxxxx series MM shocks only. These shocks have a shaft with a 5/8" major diameter, and include 2nd-Gen yellow MM shocks and 3rd-Gen black MM shocks.
  • Fits MMCO-21 Competition Coil-over kit.
  • Fits MMCO-23 Competition Coil-over kit.
  • Not for IRS
Related products
  • Allows zero vertical deflection. Rubber bushings allow deflection that reduces the overall effectiveness of the shock's damping.
  • Allows the angularity required to avoid sideways loading of the shock shaft. Such loading can bend the shaft slightly, increasing friction, reducing the effectiveness of the shock.
  • Easy installation of MMD-RCxxxx series MM shocks with MMCO-21 or MMCO-23 Competition Coil-over kit in 1979-2004 Mustang chassis.
  • Aluminum block securely mounts to chassis.
  • PTFE-lined spherical bearing
  • Mounting hardware includes spherical washer sets to accommodate the curvature of the Mustang's shock tower.
Fits
  • 1 kit fits 1 shock. 2 kits required per car.
  • 3rd-Gen black MM shocks with MMCO-23 Competition Coil-over kit
  • 2nd-Gen yellow MM shocks with MMCO-21 Competition Coil-over kit
  • These black and yellow MM shocks are in the MMD-RCxxxx series. These shocks have a shaft with a 5/8" major diameter.
  • 1979-2004 Mustang chassis
  • Solid axle suspension

Does NOT fit

  • MM shocks with 11mm shaft diameter (1st-generation MM shocks). Use MMSM-1 instead.
  • Bilstein shocks. Use MMSM-1 instead.
  • IRS suspension

Why do I want to eliminate the vertical deflection allowed by rubber upper shock bushings?
The spherical bearing also allows instantaneous damping from the shock when the suspension moves. With a compliant upper mount such as rubber, the mount deflects vertically before the shock moves, so no damping occurs over smaller bumps. Removing this rubber significantly reduces the chances of damaging wheel hop from the added damping over small, normal road bumps.

Why do I want to eliminate the lateral stiffness caused by rubber or polyurethane upper shock bushings?
During cornering, when the suspension articulates as the body rolls, the angle between the shock and the chassis changes. The bushing at the top of the shock resists this angular change, resulting in a side load inside the shock between the piston seal and the inside of the shock tube. This side load creates more friction, keeping the suspension from easily extending or compressing. This type of friction causes the car to ride and handle worse, because when the suspension then encounters a small bump, the bump force isn't enough to overcome the friction force to allow the suspension to move. If the bump force is too low compared to the friction level, the car will merely bounce along on its tires rather than effectively engaging the suspension system, causing poor handling and tire wear.

You can read Maximum Motorsports' highly detailed MMSM-12 Racing Upper Shock Mount installation instructions before purchase.