FLOATING FRONT PRIMARY GEAR BUSH [C-AEA3240]

PRODUCT OVERVIEW

Floating front primary gear bush, designed as a practical solution for worn or troublesome front primary gear bush applications.

This is a favourite option for racers and professional engine builders because it avoids the extra cost of fitting and machining a traditional fixed bush. It is fully floating, 22.5mm wide and ideal for use on stepped-type 1275cc crankshafts when the primary gear and crank are suitable.

This bush is not the top-hat type rear bush.

SPECIFICATIONS

• Application: Front primary gear bush
• Bush type: Fully floating
• Width: 22.5mm
• Front bush internal diameter: 1.628″ +0.002″ / -0.0″
• Gear internal diameter: 1.750″
• Bush outside diameter: 1.748″ +/- 0.0005″
• 2024 measurements: 44.40 / 44.38mm O.D.
• 2024 internal measurements: 41.375 / 41.34mm I.D.
• Length: 22.50mm
• Shorter 19.85mm version available separately: [C-AEA3241]
• 1 required per primary gear

SUITABILITY

This bush is suitable for Minispares manufactured helical primary gears and Minispares straight cut primary gears made after 2015.

It is not suitable for early Cooper S primary gears with the larger internal dimension, original A+ helical primary gears, or Minispares straight cut primary gears manufactured before 2015.

IMPORTANT FITMENT NOTE

Remove the old bush and clean the area carefully with wet and dry paper before fitting. The new bush should be oiled before installation.

Always ensure the bush butts up squarely to the shoulder, with the oil holes sitting correctly in the trough and not on the edge of the stop step. If the oil drain holes sit incorrectly, they can act like cutting edges and damage the bush.

Check that the crankshaft is not worn, marked or blemished. Also check that the inner bush area of the primary gear has not been machined on an angle near the oil hole, as this can shred the new floating bush. This angled machining issue is common on many A+ gears.

BUILDING NOTE

Racers and professional engine builders may use their own clearances and tolerances, but this bush is supplied set for road use. Always measure carefully before final assembly, especially on performance or race engines.