B&M uses 180 straight cut planetary gears.
The gears are machined from E9310 steel
and provide better launch characteristics
and superior acceleration for heavier, high
horsepower cars. The stock gear is helical
cut 176.
The reaction sun gear is splined into
the drum backing plate. Welding the reaction
sun gear into the backing plate can compromise
the metallurgy of the reaction sun gear,
which may result in gear failure.
At left is stock helical 1:76 reaction
sun gear, compared to the 180 straight cut
reaction sun gear at right.
A dual ring servo assembly provides improved
sealing for better band application. The
stock servo is at left.
The valve body is modified and re-machined
to provide transbrake operation.
