Precision Measurement Supply - Fixtures, Tooling And Measuring Devices For Professional Engine Builders

Bellhousing Indexing Fixture Instructions

1. Remove stock dowel pins from engine block.

2. Install dowel pins supplied in kit.

3. Enlarge dowel pin holes in bellhousing 1/16” (in some cases it may be necessary to drill out bellhousing mounting holes).  In most cases, 1/32” over size will be sufficient.  

4. Install bellhousing onto block using two mounting bolts placed opposite one another.  

5. Lightly tighten bolts so that bellhousing can be adjusted by lightly tapping with a soft hammer.  

6. Mount dial indicator base securely to crank flange or flywheel.  Align indicator stem 90 degrees to crankshaft centerline, resting stem on transmission register hole.  

7. Rotate crankshaft 360 degrees and observe highest reading of indicator at the point. Reset indicator to zero and rotate crankshaft another 360 degrees.  The highest reading reached on the indicator (divided in half) is the amount the bellhousing must be moved for proper alignment.

8. Move bellhousing in the direction of the highest indicator reading.  (By one half the highest indicator reading.) 

NOTE:  It is important to observe in which direction the indicator stem is traveling when reading the indicator so as not to move (adjust) the bellhousing in the wrong direction thereby doubling the amount of misalignment shown on the indicator face rather than correcting it.  

9. Now tighten all bellhousing mounting bolts in a zigzag pattern and recheck with indicator for correct alignment.  In some extreme cases, it may be necessary to enlarge the locating holes and/or mounting holes more than the recommended 1/16” to correct the misalignment problem.

10. After correct alignment of the bellhousing has been established, install washers provided in kit over dowel pins with chamfer against bellhousing.  Weld washers directly to bellhousing.  On some model bellhousings it may be necessary to modify washers to clear the bellhousing or other obstructions.

NOTE:  By welding only a small section to the bellhousing, the washers may be removed when installing and indicating the bellhousing on another block

 

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