Mallory Ignition Lakewood QUICKTIME SAFETY BELLHOUSING - Manual (Page 3)

3 www.lakewood-industries.com
WELD-ON DOWEL LOCATING KIT
Designed for use on race cars that are frequently dis-assembled, this kit eliminates the need to “dial- in” the bellhousing after each
removal. Ford/Mopar engines with .500” dowel holes use #15980. GM engines with .625”dowel holes use #15981.
NOTE: Welding is required to use this kit.
Total Indicator
Reading
One-Half Total
Indicator Reading
Size Dowel
To Be Used
Lakewood Offset Dowel Part Number
GM .625” dia. Ford/Mopar .500” dia.*
.012” to .020” .006” to .010” .007” #15920 #15950
.022” to .034” .011” to .017” .014” #15930 #15960
.036” to .052” .018” to .026” .021” #15940 #15970
*Off-set dowel pins are not available for Ford 4.6/5.4L engines
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 case.
While most bellhousings will fall within the allowable limits, it is
good practice to check for register bore run out whenever any
bellhousing 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.
Offset dowel pins are available from Lakewood Industries to
ensure correct bellhousing 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.
Special note for bellhousings that are designed for T-56
transmissions: In order to check register bore run out on
these bellhousings, you must remove the front plate from the
transmission and mount it to the bell. This will allow you to check
for run out by following the instructions below.
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.
3. Rotate the flywheel and note indicator reading. Misalignment is
one-half 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 out from back side or
pulling out with gripper pliers.
6. Clean engine block dowel holes and coat lightly with lubricant.
7. Lubricate dowel pins and install in block. Note the position of
the offset and mark the dowel for reference. They should be
installed parallel to one another and in pairs (both .007”, .014”
and .021”).
8. Install and tighten bellhousing securely. Remount the dial
indicator and recheck the register bore run-out (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 and 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.
BELLHOUSING ALIGNMENT PROCEDURE