Bicycle Mechanics - Hub not rolling smoothly

I changed the shaft of a Dura-Ace 7600 hub.
After putting it back together, it made some noise when rolling and was noticeably less smooth.
It's an open bearing hub, so it's possible some dirt got inside.
I opened it up again and cleaned out the hub and re-greased completely. It was still not much better. I then exchanged all balls and greased again with dura-ace grease.
The noise is gone now, but compared to my front wheel it doesn't run quite as smooth anymore. When holding it in your hands and turning the wheel you can feel a tiny unevenness somewhere.
It's possible that the hub itself has some pits from the dirt that got in? I couldn't see any with my bare eyes however.

I am trying to find out if using the wheel like this will make the problem worse.
Any advice would be greatly appreciated.

Thanks

Are your cones too tight?

I played around a lot adjusting those. I got it to a point where noise is almost gone. It does roll ok, but not perfectly smooth like the front one.

sounds like you may have pitted it. I doubt you'll notice it when riding though, so I wouldn't worry too much. If you cleaned everything out good and put in fresh grease you really aren't going to make it worse by riding.

http://sheldonbrown.com/tooltips/hubs.html

http://sheldonbrown.com/cone-adjustment.html

I would take out the axle, degrease it and polish the races.

And then put it back together properly. It may take a while with subtle adjustments to get it right.

How can I examine the cups for pitting other than with the bare eye?
In some youtube tutorials they use a sharp pencil to trace the surface and try to feel for any unevenness.
Does anybody have experience with that? Any suggestions?

Unless they are visibly pitted they're probably fine. I've reassembled hubs with some pitting and still been able to get them to spin smoothly. Either you have dirt in there, (unlikely after all your cleaning) or you're adjusting the cones too tight. It's a very precise adjustment, it takes always takes me a few tries to get it just right.

I was working with one cone wrench and two adjustable socket wrenches. I think I'll go and invest some money in two 14mm cone wrenches and a dedicated 18mm wrench for the lock nut. (after reading sheldon's article ...)
I'll try to play around a bit more with the cone adjustments, see if I can get it any smoother.
Thanks for all your help.

Remember QR skewer compresses the axle, when you close the lever,
and makes the adjustment tighter than it was.

Pro team mechanic's setup was a spare set of dropouts
just like on the Bikes, .. to get that right.

Don't worry about how it feels in your hand. There should be a slight amount of play in the bearing adjustment that goes away when the quick release is closed.

Unless they are visibly pitted they're probably fine. I've reassembled hubs with some pitting and still been able to get them to spin smoothly. Either you have dirt in there, (unlikely after all your cleaning) or you're adjusting the cones too tight. It's a very precise adjustment, it takes always takes me a few tries to get it just right.

This. There's a bit of an art to it... though nicer gear is usually much more straightforward to tune. Surprised to hear you're having trouble with Dura-Ace, unless you're doing something wrong... they're some of the sweetest hubs made, IMO

Don't worry about how it feels in your hand. There should be a slight amount of play in the bearing adjustment that goes away when the quick release is closed.
Sorry about this one. The hub is a single speed with Bearing cages. Make sure the cages are oriented properly and that there is a little preload in the bearings.
http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/HB/EV-HB-7600-R-728A_v1_m56577569830672572.pdf

Bearing preload is a fair bit easier to set on hubs with wheelnuts... there's no guesswork.

I guess the below picture would explain what was wrong.
I didn't see this the first time, but just took it apart again, degreased and cleaned all parts again.
This is what I found while scooping out the grease from the bearing cup. I think it's a piece of metal from the key washer. I'm not sure how it got in there, since the washer goes on top of the cone.
Amazingly there are no pits still.
I am just glad I didn't ride the wheel like this. Otherwise I would've probably pitted the hub.
198483

I was working with one cone wrench and two adjustable socket wrenches. I think I'll go and invest some money in two 14mm cone wrenches and a dedicated 18mm wrench for the lock nut. (after reading sheldon's article ...)
Check the locknut size before you buy the wrench. Most of the hex locknuts on Shimano hubs I've worked on are 17 mm.

thanks for the heads-up.
The 7600 front hub uses 13mm on the cone and 17mm for the locknut. The rear uses 14mm on the cone and 18mm on the locknut. At least for the 120mm-->110mm conversion axle I am using. I did measure them before I went to buy wrenches. 18mm was actually hard to find. Doesn't seem to be a common size.

Anyhow, hub is rolling smoothly now, and it'll get some test riding on the track tomorrow!