# Weird converter/crankshaft pilot bore size



## Mors (Jul 12, 2018)

I have a 69 GTO w/ TH400, and for some reason the crankshaft pilot bore measures 1.685 rather than the standard 1.703. As far as I know the crankshaft is stock, but I'm the 3rd owner so who knows what went on in the past. The smaller pilot bore size in the crank is making it impossible for me to replace the torque converter as none of them have a pilot hub small enough to fit. So far no machine shop is willing to try turning down the pilot hub the .0021 I need to clear it and I haven't had much luck finding anyone else with a similar issue. I appreciate any suggestions. Thanks!


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## RMTZ67 (Mar 12, 2011)

*pilot bore*



Mors said:


> I have a 69 GTO w/ TH400, and for some reason the crankshaft pilot bore measures 1.685 rather than the standard 1.703. As far as I know the crankshaft is stock, but I'm the 3rd owner so who knows what went on in the past. The smaller pilot bore size in the crank is making it impossible for me to replace the torque converter as none of them have a pilot hub small enough to fit. So far no machine shop is willing to try turning down the pilot hub the .0021 I need to clear it and I haven't had much luck finding anyone else with a similar issue. I appreciate any suggestions. Thanks!


Am I missing something? I thought the crank pilot bore was for manual transmission. are you talking flywheel?:confused


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## Mors (Jul 12, 2018)

On the back of the torque converter there's a short pilot hub (the snout/nose) that goes through the flexplate and slides into the end of the crank.

Edit: I also found out today I can ship it to TCI and they'll take the nose down so that's likely the solution I'll go with.


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