ImBatman

I have a lakewood bellhousing that I ran in the late '80's on a sb that I was planning on usingon the Vette. Yesterday on 2 guys garage they were talking about checking runnout of the opening of the bell housing and the alinment with the crank snout. Now I see in this months CHP that they have an article on the same thing. I have never heard of this until now. Supposedly the BH can be out enough that it would cause missed shifts. :confused: Is this a new thing?

gerry72

No, it's not a NEW thing. It's fairly common when using an aftermarket steel housing to check this since most of these hydroformed housings tend to be off. Much as you'd expect, the offset causes the input shaft to be misaligned with the pilot bearing which puts the gears out of alignment. It's well worth the time to get the housing right. Offset guide pins are available to center the housing relative to the crank centerline.

ImBatman

Great thanks! I guess this is just one of those things that I never realy thought about. :smash:


Wade

467-Ratman

I watched the show too, now I am thinking that could be why my Muncie does not like to hit third gear sometimes and pops out of 4th. We did not check to see the runout on my lakewood either

norvalwilhelm

When I got my new tremec they specified .005 maximum run out. I always check the bellhousing before installing a transmission. It is easy to do.
You need the fly wheel on the motor but no clutch. Install the bellhousing, put a magnetic base on the flywheel with a short extension coming out the hole with a dial guag mounted so it's tip runs around the hole in the bellhousing. I place a large mirror under the car behind the bellhousing but so I can lay under the motor and turn it over with a large torque wrench. Make sure the plugs are out. Anyway you can watch the dial indicator going around and read maximum run out. If you start at say 3 oclock zero the dial indicator and turn it to 9 oclock and take a reading. Take reading also at 12 and 6 oclock. If the maximum reading is say .010 you half it for run out or .005 runout. This is absolute maximum.
If you have say .020 maximum reading that is .010 runout and too much. You can buy offset dowels to move the bellhousing in the direction you want.
I work on mine until I get 0 or very very close to it.
I know my transmission main imput shaft is running down the center of my crank and no binding is taking place.
For those that didn't see the show hope this explaination of procedure helps.