Aligning Bellhousing

[SCFFR]

Getting ready to start the process of centering the bellhousing on the engine block. Have done quite a bit of research and printed out several articles to reference and understand what I need to do but have one big question. All of the articles say to put the magnetic base that the dial indicator is attached to as near as possible to the center of the crank. When the crank is turned by hand, the tip of the indicator will run around the opening in the bellhousing and by looking at the various readings, you can move the bellhousing accordingly to get it centered. I just can’t understand how this works if the dial indicator is not exactly in the center of the crank axis. If its off center, it seems to me that you end up aligning the bellhousing with this off-center location.

Would appreciate any help in understanding how this process works.

I did see in an article where there is a tool that bolts to the crankshaft and lets you center the bellhousing very easily but its almost $150 which seems steep for a one time use.

Many thanks

[michael everson]

It works because your rotating the engines crankshaft. the indicator base doesnt care were it is on the flywheel. Its just going around in circles.

[edwardb]

Fix the dial indicator to the back of the crank, flywheel, whatever. At that location, set the dial indicator to zero against the bell housing opening. Then rotate the engine checking the dial indicator reading, typically at each 90 degrees or so. It shouldn't move from zero any more than the required tolerance, typically .005. As long as the dial indicator base doesn't move, it doesn't matter whether it's in the center or not. You're measuring the difference between the two concentric circles (crank and bell housing opening) not whether the indicator is in the exact center. Hopefully this makes sense.

Edit: Mike beat me with a shorter (and probably better) explanation.

[oldguy668]

Okay...I still don't get ti. Maybe this guy can explain it...

9703

[carbon fiber]

smart guy, he had some crazy theory about time, space, and bending light. whatever happened to that?...

[SCFFR]

Thanks guys. I think I finally see the light.......................

[Crawleyscobra]

Browell Bellhousing Alignment Tool.

So easy even a cave man can do it.

http://browellbellhousing.com/components.html#

[SCFFR]

Thanks again.....................that's the exact tool I was talking about. Will try the dial indicator first and if I can't get it to work (i.e., I can't work it), will get the Browell tool and try to sell it after I use it.

[EBarnes]

As long as the dial indicator does not move relative to the center of the rotation (the crank), it will always be the same distance from that center. Remember, you are turning the crank, not the dial indicator!

The dial indicator then measures the remaining distance from the center of the rotation, and the variations as it goes around.

Some good YouTube videos on it also!

HTH,

[SCFFR]

Thanks again for all of the information. The part I was overlooking was zeroing the dial indicator once it was set. This allows you to measure any offset when the crank is rotated.

Much appreciated!