Project Silvia’s Girlfirend Part 2: Making it Handle

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I'll save you the agony of all the incorrect diagnoses I made and just show you the answer. See the problem? No, I didn't see it at first either… This is the inside of the Attain 5-lug hub after pressing out the bearing cartridge. These are chatter marks from the dull and/or flexible cutting tool some Chinese child was using to make this hub. The resulting shape is so far from round that the bearing cartridge isn't making full contact with the inside of the hub.

Under hard cornering loads, the poorly supported bearing cartridge would slip slightly in the hub, rocking back and forth with each revolution and making that GRONK-GRONK-GRONK noise. The point loads where the bearing shell actually was contacting the hub were so high the shell and hub were actually friction welding themselves together, then breaking the welds when they slipped. You can see the ring of broken friction weld around the top of the hub bore in this shot, along with the vertical streak marks where that jagged broken weld was pressed out of the bore.

Right in the middle of the bearing cartridge you can see three little fingers with tiny little pimples on them. Those pimples are more broken friction welds.

So that's the downside to the S13 5-lug conversion hubs. If you're hard parking, you'll probably never have a problem, but if you actually intend to go around a corner, manufacturing quality matters. On the bright side, S13s use replaceable bearing cartridges, so this is a serviceable part. S14 bearings are machined into the hub, so when you have a bearing failure on an S14 hub, you have to buy a whole new hub from Nissan. No aftermarket bearing suppliers have S14 bearings. Some claim to, but they mistakenly list the same bearing for S13s and S14s.

So, here's how we fixed the problem:

First, I put the hub in a lathe and honed the hub bore with sandpaper and my finger. This doesn't make the bore any more round, but it does remove the high spots left from all that friction welding and stick-slip nonsense.

Next, I cleaned the bore, and the shell of a brand new bearing carrtidge, with Loctite cleaner/primer.

Strangely, I took a picture of the primer, but not of the stuff I was priming it for. Or maybe I did take a picture and I somehow only lost that one. Anyways, Loctite Bearing Mount 620 is specifically designed for securing bearings in bores that don't quite fit properly. There's a high-temperature version of the stuff too, and that's what you need to survive in the middle of a brake rotor.