Crank cutting into #3 main bearing

[Gregs672000]

Exactly. The end of the trans input shaft just bearly reached the bushing. I think that just a little bit of misalignment had the shaft pressing the crank forward. As I recall, the trans had some resistance to bolting to the block. I may have even used the bolts to draw the two together... who knows, but I'm pretty sure I pushed the bushing further and further in, perhaps over several years as I have never seen need to change out the bushing.

[Linda]

JT wrote:

If you have to go past .010, I'd suggest you find aother crank or have yours nitrided since I know you will run it hard. .020 is through the factory nitriding. J

How much is nitriding? I wonder if local shops like this are likely to do that. My machinist recommended them for polishing the crank:
www.recordcrankshaft.com
Linda

[C.Costine]

Exactly. The end of the trans input shaft just bearly reached the bushing. I think that just a little bit of misalignment had the shaft pressing the crank forward. As I recall, the trans had some resistance to bolting to the block. I may have even used the bolts to draw the two together... who knows, but I'm pretty sure I pushed the bushing further and further in, perhaps over several years as I have never seen need to change out the bushing.

Greg, that would mean that in effect you have no pilot bushing.

[Gregs672000]

Yep! Maybe just the very tip, but that would not stop anything like the clutch etc from working so I wouldn't have noticed. But in reality, I did notice it once as did the Datsun z car guy whos dyno we were tuning on. When I put in the clutch, the rpms actuall went DOWN, not up as they should have from being free of the drag from the trans. We both noticed it, but neither of us though to much about it. Now it makes sense to me. I'm betting that the trans input shaft would push forward just a tad with the actuation of the clutch, nudging the crank even farther forward than it should. At least that's the theory I'm going with! That would mean that there was a lot of potential wobble too, which I may have noted while driving... a vibration. Guess we'll see!