The importance of measuring bell housing runout.
Don't misunderstand me....I do know the importance of precise measurements. I'm just curious as to why it seems that the new overdrives are so sensitive to runout.
My 440 block only needed .014 offset dowels to bring the bell into range.
The car I'm helping with now is over .040 off center. I wonder what the chances are of the bell itself being to blame. I wish I had another bell nearby to check. I'm going to put the word out to some local friends. I'd like to borrow one to do a test fit and measure.
The vendor requires documentation of measuring the runout to no more than .005 or less to warranty the transmission. When you spend $7000 on one of these kits, you're inclined to do what it takes to get it right.
I have one friend that set aside a bellhousing for me to use. I wouldn't mind another though. If the other bells also have excessive runout in the same direction, it seems that would indicate an indexing issue with the crank not being centered or the mounting surface of the block being drilled out of spec.
Sometimes weird stuff happens and you have to find a way around it.
To the topic of automatic transmissions...
I noticed during my 5 speed swap when I pulled the flex plate off of my 440/493, it had 2 cracked ears.
I had a buddy that cracked the hubs on 2 different flexplates within a couple of months on this car:
It was just a mild 360.
What about you? Have you accidently found broken parts like this and didn't know what caused it?
What if all along it was excessive runout?
Don't misunderstand me....I do know the importance of precise measurements. I'm just curious as to why it seems that the new overdrives are so sensitive to runout.
My 440 block only needed .014 offset dowels to bring the bell into range.
The car I'm helping with now is over .040 off center. I wonder what the chances are of the bell itself being to blame. I wish I had another bell nearby to check. I'm going to put the word out to some local friends. I'd like to borrow one to do a test fit and measure.
The vendor requires documentation of measuring the runout to no more than .005 or less to warranty the transmission. When you spend $7000 on one of these kits, you're inclined to do what it takes to get it right.
I have one friend that set aside a bellhousing for me to use. I wouldn't mind another though. If the other bells also have excessive runout in the same direction, it seems that would indicate an indexing issue with the crank not being centered or the mounting surface of the block being drilled out of spec.
Sometimes weird stuff happens and you have to find a way around it.
To the topic of automatic transmissions...
I noticed during my 5 speed swap when I pulled the flex plate off of my 440/493, it had 2 cracked ears.
I had a buddy that cracked the hubs on 2 different flexplates within a couple of months on this car:
It was just a mild 360.
What about you? Have you accidently found broken parts like this and didn't know what caused it?
What if all along it was excessive runout?
