Mc Leod Bellhousing Alignment Procedure - Manual

Bell Housing Alignment Procedure
When swapping a clutch, bell housing or
transmission it is highly recommended you check the
alignment of the bell housing to the engine
block/crankshaft and to the transmission input
shaft/output shaft. Think of this as a theoretical
straight line running through the crankshaft, through
the input shaft of the transmission and the output
shaft of the transmission. Misalignment along this
path can lead to leaks, premature wear of
components and excessively noisy operation. This
inspection can be performed with a few common
measuring devices and some time. Manufacturers
tolerances of engine/crankshaft alignment can vary
especially if the engine block has been modified
throughout its lifetime or if you are performing a bell
housing and/or transmission swap. If you find excess
misalignment on your engine/bell housing you can
correct the problem with off-set dowel pins.
(Lakewood Industries offers Offset dowel Pins to
correct misalignment conditions). You will need a
dial indicator with a magnetic base along with some
typical hand tools to perform this inspection. It is
critical you pay close attention to detail when
performing this inspection in order to achieve
accurate assembly results.
1) Install flywheel onto crankshaft, using proper bolts and torque to factory setting.
2) Be certain the engine block dowel pins stick out of the rear of the engine block at least ½” for
proper bell housing engagement. Check the rear surface of the engine block at this time to be
certain it is free of nicks or burrs that will prevent the bell housing from seating against the block.
3) Install just the bell housing and hold in place with a few bolts. Install dial indicator base onto
flywheel near the center of flywheel and adjust plunger to contact the register bore of the bell
housing. Rotate the flywheel and note the indicator reading as you sweep the register bore of the
bell housing.
4) Misalignment can be determined by dividing the change in the indicator by 2. Maximum allowable
runout is .005”.
5) If your reading exceeds .005” off set dowel pins must be used to correct the misalignment.
Lakewood Industries offers such dowel pins in several sizes.
This alignment procedure will eliminate premature wear on many of the transmission and clutch
related components and will provide smoother operation.
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