Tools for adjusting bellhousing runout??

[biomedtechguy]

I used a magnetic base dial indicator, but I'm really concerned about accuracy, and even with a powerful magnet, there could be movement, and the tolerance is .010.
So there's a company that makes a fixture that plugs into the crankshaft hole where the input shaft pilot bushing goes in.
The problem is I need to measure my Mopar (to confirm previously measured runout) and Pontiac and they take different parts for the fixture to work, and it would cost around $450 for all of the parts. Browell makes the tool I'm referring to.

Anyone have any recommendations for a certain, solid way of measuring runout that is compatible with Mopar and Pontiac applications?
Thanks.

 

[andyf]

A long bolt with a long spacer will do the trick. You just torque the bolt down against the spacer and that will make it rigid enough to provide a stable measurement. Then mount the dial indicator off the end of the bolt. Or use a long stud and a double nut arrangement. I have a small collection of little tools that I've built over time to do this job. If I'm working by myself I shoot a video while I turn the engine over from the front. Then I can slowly step thru the video and see where the runout is.

 

[gkent]

Set indicator at ZERO. Rotate 45 degrees and note runout - repeat for the whole 360 degrees. If the indicator lands back at zero your worries are unfounded. You're not the first guy ever to do this.

 

[gkent]

Oh, and before you go spending money on offset dowels - depending on the runout loosening the bolts and smacking the bell with a big mallet in the right place is worth a couple thou !!

 

[dsd1967]

I just did mine with a magnetic base that attached to the crank flange. It always came back to the same reading. Only rotate in one direction and it will load the indicator the same amount.

For grins I would lift the indicator off the surface and let it lightly snap down and the results were repeatable. I marked my bell with a sharpie every 45 degrees so I took my reading at the same spot. If you go past.....keep going and come back to it in the same direction. I did at least two rotations to get my readings before making any adjustments.

 

[jamie]

A long bolt with a long spacer will do the trick. You just torque the bolt down against the spacer and that will make it rigid enough to provide a stable measurement. Then mount the dial indicator off the end of the bolt. Or use a long stud and a double nut arrangement. I have a small collection of little tools that I've built over time to do this job. If I'm working by myself I shoot a video while I turn the engine over from the front. Then I can slowly step thru the video and see where the runout is.
View attachment 949788

^^^^ And make sure to clean the paint out of the bellhousing hole if there is any.

 

[gkent]

Only rotate in one direction and it will load the indicator the same amount.

For grins I would lift the indicator off the surface and let it lightly snap down and the results were repeatable. I marked my bell with a sharpie every 45 degrees so I took my reading at the same spot. If you go past.....keep going and come back to it in the same direction. I did at least two rotations to get my readings before making any adjustments.

BINGO !!

 

[biomedtechguy]

Thanks to all!

 

[biomedtechguy]

Oh, and before you go spending money on offset dowels - depending on the runout loosening the bolts and smacking the bell with a big mallet in the right place is worth a couple thou !!

I already have an assortment of Rob Mc offset and 0 offset dowels for the Roadrunner, and I'm doing the same for the GTO. Rob Mc said I could return what I don't need.
I used one offset and one 0 offset in the Roadrunner, but that is another reason why I want to check it, because I've read you are supposed to use the same offset on both, AND I was the one turning the crank, NOT watching the dial indicator.
I'm installing a Hydramax hydraulic throwout bearing, so may as well check it.

 

[biomedtechguy]

A long bolt with a long spacer will do the trick. You just torque the bolt down against the spacer and that will make it rigid enough to provide a stable measurement. Then mount the dial indicator off the end of the bolt. Or use a long stud and a double nut arrangement. I have a small collection of little tools that I've built over time to do this job. If I'm working by myself I shoot a video while I turn the engine over from the front. Then I can slowly step thru the video and see where the runout is.
View attachment 949788

@andyf as always, I'm honored by your help. Please be detailed and specific for me, apologies if I seem too needy in asking: What hole is this bolt or stud going into? I can't tell from the picture.
This is SO important for me to get right, not only because I am accessing this area on my Passon 855 to install a Hydramax TO bearing, but I have to get this right on the new TKO600 in my wife's GTO.
So please be as detailed and specific as possible.