Nice work on tracking down and fixing the issue.

:iagree:

And thanks for following up :tup: :tiphat:

Make sure that the wheel lug nuts are torqued with a torque wrench in stages up to full torque and that they are tightened in the proper sequench. Changed many rotors that warped due to improper wheel nut tightening procedures.

Awesome, glad you got it sorted!

So the bearing was the culprit. Having similar issue, any braking from 40mph and on up causes shaking in the steering wheel, only on the drivers side. Best way I can describe it is, it feels as if the break pad is skipping, if that makes any sense. I was thinking wheel balancing, rotors or worse case scenario suspension components. There are no other symptoms though for me to think its a suspension issue. Now this has me thinking a wheel bearing. Ill have to get it looked at soon and do the spin test as you did.

When you say rebuilt the caliper, do you mean you got a reseal kit? Or you actually replaced parts of the caliper?

I have a 2010 Nismo and I have steering wheel and seat vibration at certain speeds, and under braking. The car pulls right as well. Here is what I have don't to try and fix the problem:

New tires
Road force balance
New rotors and pads
New brake fluid & several bleeds

To answer any obvious pieces of advice:

I've ensured tire pressure is always the correct pressure
I've had several alignments and tire balances.
The old rotors/pads had this problem and now have been replaced.
Rotors/pads were imbedded properly.
Pads have even wear as far as I can tell.

What is next in figuring out how to fix the steering wheel/seat vibration under braking and not braking? As well as the pulling right under braking.

I replaced the seals with a caliper rebuild kit. That said, given the stuff you've already done, you should check your wheel hubs, especially on an older car.