Rear wheel bearings failing

[Swiftman23]

Car is a 1989 240sx hatch. Has a v8 swap, r200 vlsd diff, 350z axles, 5 lug conversion with ctsv brakes.

3 weeks ago took it to the track after finishing the build, in 35min of driving both rear wheel bearings had come loose on the interior side and started grinding. I found threads on suspected issues and made spacers to move my hubs further out to give more play with my axles. Now they move freely in and out with suspension travel. Then purchased megan racing hubs to replace the previous isr ones. (Just incase it was a brand issue). Drove it 3 miles down the road and did a hard launch and felt the shimmy of bad wheel bearings. I am at a loss as to what is causing this. 😕 any ideas?

[mechanicalmoron]

Wrong torque on wheel bearings, or missing/wrong location on a spacer, washer, other part, installing bearings by pressing on the wrong part or some other damaging oversight. Brake or other part not being aligned right and bearing on something when a wheel's on, missing snap-ring or circlip, etc.

Those are not with any specific knowledge of your setup, or how well paired those components are, not even much of a mental picture. That's just where I'd look, imagining I was trying to fix a car with those complaints.

[Swiftman23]

Thank you, I will check each of those and go from there