Crank to bellhousing runout check

[66FBCharger]

How many people use a dial indicatot to check the bearing register part of the bellhousing relative to the crank?
Mine is off .018". Is this uncommon? Its the original engine and I assume original 11" cast iron bellhousing.
Do you check the runout or do you just slap it back together when swapping a clutch or trans. and not worry about it?

[John_Kunkel]

If it's that far out, it's not likely the original bellhousing. At the factory the block and the bellhousing were line-bored together.

The factory says .008" TIR is the maximum acceptable.

[timmycharger]

I used one of these tools, worked very well with the offset dowels 

[birdsandbees]

I've read a LOT of these threads the past few years and wonder HTH we ever survived our teenage years swapping engines, transmissions, bellhousings, throwing in Lakewood scatter shields and never pulling a dowel pin out of a block before installing another A833 out of some junk yard car, behind what ever motor we could find and make run. Never a chatter or clutch issue in my 58 years, 45 of those wrenching cars.

[Kern Dog]

Yeah, I agree. There must be something about the new Tremec transmissions being of tighter tolerances or something.

[alfaitalia]

Well ....I will confess that of all the engine/gearbox swaps I've done over the years....mostly non MOPAR....I've never even thought to check bellhousing runout!!. Never has an issue....so I'm either lucky or its not that critical in lots of cases.

[BSB67]

I've had one 4 speed car.  In that car I used three different belhousings, and two different transmissions.  Checked and adjusted nothing.  Not saying it's right, but it's one of those things that you have to ask,: how perfect does it need to be, and what's the likelyhood for the tolerance stack up to be bad enough to make a difference.

I've been in this hobby for 45 years, the stuff people concern themselves with today is often times very funny.  I think its the lack of understanding of history, probability and risk tolerance.

[c00nhunterjoe]

There are things i do on the race car that i dont do on the street car. Checking the runout amd making it perfect IS the right way to do it. However, i have found that the tolerances are so loose on the old transmissions that i have personally never ran into a problem nor do i know anyone in my street car world who has either. If you have modified the block, i would check it. But in 99% of cases, if you use the clutch disc tool to center it, and the trans slides right in and the bolt holes thread in with your fingers, there wont be any problems. The bigger issue is the linkage binding when the motor torques over in my opinion.

[John_Kunkel]

I've read a LOT of these threads the past few years and wonder HTH we ever survived our teenage years swapping engines, transmissions, bellhousings, throwing in Lakewood scatter shields and never pulling a dowel pin out of a block before installing another A833 out of some junk yard car, behind what ever motor we could find and make run. Never a chatter or clutch issue in my 58 years, 45 of those wrenching cars.

I'm guilty too, never had a problem until I installed a fresh Clutchflite and Lakewood housing and proceeded to wipe out the transmission pump seal in a few seconds of running time. The housing had .047" TIR.

[c00nhunterjoe]

I've read a LOT of these threads the past few years and wonder HTH we ever survived our teenage years swapping engines, transmissions, bellhousings, throwing in Lakewood scatter shields and never pulling a dowel pin out of a block before installing another A833 out of some junk yard car, behind what ever motor we could find and make run. Never a chatter or clutch issue in my 58 years, 45 of those wrenching cars.

I'm guilty too, never had a problem until I installed a fresh Clutchflite and Lakewood housing and proceeded to wipe out the transmission pump seal in a few seconds of running time. The housing had .047" TIR.

Nice, not too many people i know have run them.... or even heard about them. Great idea for the time.

[66FBCharger]

Well the reasons I'm doing the runout check is because when i went to pull the trans. out I had to use a prybar to pull it out. The next reason is the whole inside of the bellhousing was covered in gear oil. I figured being installed "off center" must have wiped the front seal out. The other reasons are I just spent a bunch of cash on a new clutch and a complete trans. rebuild and I don't want to have to pull it out again. I want it correct and working as intended.

[BSB67]

Well the reasons I'm doing the runout check is because when i went to pull the trans. out I had to use a prybar to pull it out. The next reason is the whole inside of the bellhousing was covered in gear oil. I figured being installed "off center" must have wiped the front seal out. The other reasons are I just spent a bunch of cash on a new clutch and a complete trans. rebuild and I don't want to have to pull it out again. I want it correct and working as intended.

Then why are you asking?