So last year I put a bunch of new stuff on the front end: top mounts for the struts, Koni adjustable inserts, new rotors, wheel bearings, and ball joints. I was trying to refresh everything up there to eliminate some memory steer (which I fixed by adjusting the steering column to rack connection on my MTheroy setup. i.e. completely unrelated to any of the parts I put in, lol) . To be fair the wheel bearings were a bit rough.

But after I did all of those front bits, I had a persistent and really harsh vibration in the steering from 70 to 80 mph, any speed more than that removed all of my confidence driving. And it was all front end steering wheel shake, no pedal pulse, and super smooth up to 60 mph.

Things I'd tried were different wheels and tires, new tires, rebalancing new tires (one was off by about 3/4 of an ounce, not much), swapping the old rotors and bearings back in, adjusting the inserts softer/harder.

Then I read a thread from 2012 describing exactly what I was experiencing, wherein @DivinDriver (not on since 2015!) left the nugget that "Proper per-spec front bearing pre-load is a lot tighter than most people think."

https://www.rx7club.com/1st-generati.../#post10541453

So I went back to baseline, redid the preload on the new front bearings and went tighter, test drove, better, went a bit tighter, got a lot better, went just a bit tighter, smooth all the way to 80. So lesson learned, I just wasn't preloading enough. I think I've been spoiled by cassette style hubs.

This forum continues to give good advice, 13 year old, great advice!

 

DivinDriver (Glenn) was a valuable contributor here. I still have a couple of his threads here bookmarked.

 

@DivinDriver Is still on here but not nearly as active. His last post was in 2023 looks like. I hope he is doing well.

 

Well, after the preload adjustment I had to remove and remount the wheels, the steering shake was back with a vengeance. Long story short, I had hub-centric rings at 73/60.6 mm and while they were tight for the wheel they was a just a bit of play for the hub.

So I guess it was a crap shoot each time I unmounted and remounted the wheels, and also a coincidence when it got better dramatically as I changed the preload. While the preload might have contributed, it certainly wasn't the whole story. I 3D printed a couple of 73/59.6 rings and it's eliminated the steering wheel shake.

Always more to learn!