[taff2]

Looking at the dark areas in the crack it does appear to have started cracking a while back. Definitely got some cap fretting,what are you revving it to? And why are there main studs on only number 2 and 4 mains?
You could also do with modifying the thrust bearing, file a small chamfer along the parting lines of the shells- about 0.020" will do it. Have you restricted the oil flow to the converter/cooling circuit in the TH400? You sound like you have a recurring problem with the thrust bearing and modified TH400's are notorious for causing engine thrust bearing wear. Increased trans line pressure translates into higher cooler circuit pressure which can force the converter forward,causing thrust bearing problems.

[twooldgoats]

Originally Posted by taff2

......
You could also do with modifying the thrust bearing, file a small chamfer along the parting lines of the shells- about 0.020" will do it. Have you restricted the oil flow to the converter/cooling circuit in the TH400? You sound like you have a recurring problem with the thrust bearing and modified TH400's are notorious for causing engine thrust bearing wear. Increased trans line pressure translates into higher cooler circuit pressure which can force the converter forward,causing thrust bearing problems.

Yes, definitely. I experienced thrust issues with my '64 GTO engine until we made these two mods.

Jim

[461-69bird]

Originally Posted by taff2

Looking at the dark areas in the crack it does appear to have started cracking a while back. Definitely got some cap fretting,what are you revving it to? And why are there main studs on only number 2 and 4 mains?



You could also do with modifying the thrust bearing, file a small chamfer along the parting lines of the shells- about 0.020" will do it. Have you restricted the oil flow to the converter/cooling circuit in the TH400?

shifting at 5500, max ever revved to 6200 but usually 5800 at finish line

don`t know about the studs, that`s how it was built. the Milodon windage tray was bolted to the studs

both of those mods were done

[i82much]

Originally Posted by 461-69bird

shifting at 5500, max ever revved to 6200 but usually 5800 at finish line

don`t know about the studs, that`s how it was built. the Milodon windage tray was bolted to the studs

both of those mods were done

I wonder if post #2 in this thread answers your question?

http://www.gtoforum.com/f50/455-main...uestion-55713/