I had similar problem but the freehub was too loose. This email from John reprinted below will probably help you. I followed his instructions except I tightened the end caps on the cassette side and adjusted preload of the bearings on the non-drive side. Despite what John was saying about no adjustment on the bearing, I found that the hub axle can be too loose/tight if preload is not correct (even though they are sealed bearings):
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Here’s the instructions on the hub
http://www.neuvationcycling.com/medi...aintenance.pdf
There is no adjustment possible on the hub. The bearings themselves sit on the axle and account for the adjustment. If something is tight either the bearings are not pressed in properly (very unusual) but more probably the seal between the cassette body and the hub is not seating properly. Everything should go on the axle and the end caps should be fit snug or somewhat tight but the tightening of the end caps does not affect the adjustment of the hub. If it does there is something wrong with the assembly.
Thanks,
John Neugent
Neuvation Cycling
3547 S Higuera Street Ste F
San Luis Obispo CA 93401
Toll free 877-222-4519
Fax 413-480-3024
John@NeuvationCycling.com
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From: XXXXX
Sent: Monday, January 25, 2010 9:14 AM
To:
CustomerService@NeuvationCycling.com
Subject: r28 aero 4 problem
Hi NC:
I purchased an r24 aero 4 from you about 2 months ago. Ive been getting a clicking from the rear wheel. I took it off the bike and inspected wheel. The rear axle was loose. The freehub body spun right off the hub exposing the pawls. No problem, I threaded freehub body back on hub and tightened axle by hand. I noticed that its easy to overtighten the axle which causes the bearings to be too tight. There are no flats on the axle so I dont know how else to tighten - which currently was barely finger tight.
Rode another 200 miles and clicking is back. Noticed axle was loose. QR skewer is tight. Not sure how else to avoid the axle from loosening.
Is there a trick to assembling the hubs and tighten the axle beyond finger tight and still have proper loading on the bearings? Maybe an exploded diagram will help. Surely the hub is designed so that the axle can be locked with an allen or something to prevent this situation from happening. Id say there is ~1000 miles on the rear wheel.
TIA for the help!