Due to manufacturers’ machining tolerances of engine blocks in relationship to dowel pin location, it is quite
possible for the crankshaft centerline and bellhousing bore to be misaligned. With the transmission installed in
a misaligned condition, several problems can occur, such as pilot bearing and main shaft bearing wear,
difficulty in shifting, and in extreme cases breakage of transmission gears and cases. While most housings will
fall within the allowable limits, it is good insurance to check for register bore runout whenever any housing
or engine block is installed. Most factory service manuals will outline the checking procedure, but will not give
correctional measures necessary to ensure trouble-free standard transmission operation, short of trial and error
with switching of various O.E. housings.
NOTE: Adjustable dowels are used to dial in bellhousings because the
engine blocks casted from the OEM factory can be out of tolerance. So, you
will need to align engine and bellhousing.
Offset dowel pins are available from Lakewood Industries to ensure correct
adapter housing installation. For checking, you will need a dial indicator
(preferably with a magnetic base), a few simple tools and close
attention to detail to give you accurate installation results.
INSTRUCTIONS
1. Remove clutch assembly from flywheel and install bellhousing on
engine block. (It is easier when you leave the clutch assembly off the
flywheel.)
2. Install dial indicator base on the flywheel and adjust plunger to contact
the register bore of the housing. (See photo.)

3. Rotate the flywheel and note indicator reading. Misalignment is onehalf
of the indicator reading
(maximum allowable is .005”).
4. To correct off-center condition, select the offset dowel pin pair that is
closest to one-half of the
indicator reading. (i.e., if reading is .016”, 1/2R=.008” use .007” dowels.
If reading is .024”, 1/2R=.012” use .014” dowels).
5. Remove stock dowel pins by driving from back side or pulling with
gripper pliers.
6. Clean engine block dowel holes and coat lightly with lubricant.
7. Lubricate dowel pins and install in block. The slot in the dowel pins
indicates the direction of maximum offset. They should be installed
parallel to one another, and in pairs (both .007” or both .014” and
.021”).
8. Install and tighten bellhousing securely. Remount the dial indicator
and recheck the register bore runout (Repeat step 3).
9. To make small corrections or adjustments to the alignment, you will
need to remove the bellhousing and drive the offset dowels out of
the block. Reposition the dowels using the slot as a reference point
and re-install. Re-check register bore run-out. Repeat this procedure
until the register bore is
within limits.
NOTE: Always be careful when removing bellhousing from engine
block so that offset dowel pins do not move or change position.