Repeated wheel bearing failure

I've got a problem with my 2007 Tacoma 4x4. I don't know what the problem is exactly, but its causing the front driver side hub and bearing assembly to fail over and over again. I am now on my 6th hub and bearing assembly since I started having this problem 2 years ago.
It all started when I was trail running out in the desert. I was going about 45mph and drove into a washout that was about 2 feet deep. I flew over the majority of the washout, but when the wheels hit the embankment on the other side... oooooh boy, flew up about 10 feet in the air and landed almost exclusively on the front driver side!
The obvious damage at that time was a snapped shock, bent wheel bearing, and bent CV half-shaft. But once I started working on it, I discovered that the impact had bent the lower control arm mounts inward. Frame damage = new truck, but I cannot afford one. So I towed it to my buddy's shop where we cut the old mount off, fabricated a new one and welded it on. While we were at it, we also reinforced the crappy alignment cam tabs that bend over so easy on all the other lower control-arm mounts. I replaced all 4 shocks, both front hub and bearing assemblies, the driver side CV axle, the upper driver-side ball-joint, and all the front bushings. And since then, I have also replaced the lower control-arm (with ball-joint) and the inner steering rod-end.
I want to make this very clear: I HAVE NOT BEEN USING CHEAP CHINESE REPLACEMENT PARTS. I know they suck. All the suspension parts are the best ones that Napa offers, and the wheel bearings have all been Koyo brand. In addition, I also want to make it clear that during each wheel bearing replacement, I cleaned out the old grease, packed new grease meant for wheel bearings, and replaced the inner seal that presses into the knuckle.
I have noted a very strange thing when changing these hub assemblies: I am unable to torque the stub-axle nut to the 173ft-lbs its supposed to be torqued to. Only on the driver's side. The passenger side hasn't given me any issues and is still using the same hub assembly that I installed immediately following my wash-out accident. When I go to torque that nut, it almost feels like there's a crush-washer in it. If I tighten the nut more than 50ft-lbs, the rotation of the bearing begins to get harder. If I torque to the full 173ft-lbs, the bearing cannot be turned by hand. Backing the nut off does NOT make the bearing spin free again... as if there's a crush-washer in there for adjustment, except I know there isn't. I have tried a new bearing assembly with the nut at full torque, and that bearing lasted about 3 days. I have tried a new bearing with the nut only tightened to 50ft-lbs, and that bearing lasted a few weeks. I have tried tightening the nut while checking rotational torque of the hub, stopping when the torque required to spin the hub got to 45inch-lbs, as suggested by a friend. That bearing lasted about 1-1/2 months. No matter what I do, that front driver side wheel bearing just doesn't last. I have also noted tire tread wear that would indicate excessive toe-in, despite getting the alignment done after each of the first 3 wheel bearing replacements. After that, I just decided it wasn't worth spending 80 bucks on an alignment that won't make a difference.
I have come to the point that I am thinking I must have bent the frame in some way that isn't visible. My other theory is that perhaps the replacement CV axle I put in when these problems started, was manufactured wrong. Is there a shoulder on that shaft that the inner bearing race is supposed to register against? I don't know, but if so, I would think that could allow the bearing to be pressed together more.
I am an experienced machinist, and although I've never been a mechanic professionally, I have always done all the work on my own vehicles. This problem is beyond me, and I am open to ANY AND ALL ideas as to what is going on here. Please help!

 

There's your problem. Something is still bent. Frame, suspension, ect.

 

That would be the most logical and obvious cause.
The CV stub and hub are supposed to be designed so that the inner races of the bearing are compressed when the nut is tightened, this sets the pre-load on the bearings. That is why it's important to properly torque the retaining nut and not over or under torque it.
The fact the bearing gets tight to turn when properly torqued suggests either the hub or CV stub is not made properly and is contacting something besides the inner race of the bearing causing failure

 

I agree something is bent. I just swapped for new wheel bearings after 85k on 35s. something up front is tweaked causing your hubs to wear out. Have you checked your spindle?

 

I originally though bent spindle or something like that too because they are known to bend, but how would that cause the bearing to get tight when torquing the CV axle nut? The spindles bend on the tall skinny part where the upper balljoint connects. How would that cause the bearing to get tight before it could be fully torqued to the CV axle?

I would take the CV axle out and slide it into a new bearing. Make sure it looks like it's meeting up with the inner race of the wheel bearing correctly. It sounds like the CV axle isn't sliding into the hub correctly. Instead of pulling the CV axle into the hub as you tighten the nut you are forcing the bearings inner race towards the axle.

 

I have a question on your statement that, "during each wheel bearing replacement, I cleaned out the old grease, packed new grease meant for wheel bearings .." The wheel bearings used in a Tacoma are sealed and do not require packing.

That said, I think @Dm93 is onto the root cause with something being bent. An impact like you described can cause all sorts of hidden damage.

 

Replace the cv axle, spindle, and bearing + seals. If the bearing to spindle bolts and the cv axle nut is not tightened to spec the bearing will fail, would be the first thing I would fix, if you are replacing the spindle I would cough up the extra cash and buy some that are gusseted. Its of course possibly that the frame has a twist to and/or the new table you and your friend welded on are not at the exact correct placement/angle.

 

MgmDesertTaco: Yeah, I reckon it looked kinda like that, but not quite that bad.
Anybody with half a brain would recommend I get a new truck, but I just can't afford it right now. With just under 200k on the odo, its just barely broke-in for a Toyota . Hell, my last one was a '94 pickup V6 4x4, and I gave that one to a friend with 476,000 miles on it... still running strong! I don't sell my vehicles, I run them into the ground
That said, I don't feel like this truck is quite ready for "the ground" yet. Everything else still works too well.
The only original part still on the front driver-side is the steering knuckle. And it is a critical part as far as the fitment of the hub assembly goes, so I am gonna replace it when my current bearing has had enough. I just read something in another forum about the construction of these hub assemblies, that makes me think a bent knuckle could affect the bearing more than I previously thought. Apparently there is no outer race, and the cast steel housing is locally hardened to act as a race. Knowing this, I imagine that tightening the 4 mount bolts of the bearing down onto a bent knuckle surface would impart stresses into the bearing housing that would distort the race and cause the bearing to fail. So I will run an indicator over that surface to check its flatness, but I'm still gonna replace that knuckle regardless. If it is bent, its not bent enough to see, or I would have already replaced it.
I will post my findings here, but it may be a couple weeks. I still have some time left on my current bearing, and I've been trying to get as much time as I feel is safe on each one before changing it.

On another note, I just got to see the array of excellent emojis available, and want to praise whoever is responsible for implementing those.

 

All my hard offroad trucks eat wheel bearings.

Water is the enemy, but ultimately abuse is as well.

That said I skip napa from now on, the quality seemed good at first, but disappointed with the short term failures.

 

I have a theory as to why NAPA used to be the best of the "parts store" brands, but now seems to be just as bad as all the rest. I believe that most consumers believe that all parts (OEM and aftermarket) are all the same. The only difference is the price. So why pay more for what are essentially the same parts? (Of course, all of that is BS.) NAPA was trying to differentiate themselves by selling premium aftermarket parts - but nobody cared. Well, if you can't beat them, join them.

Personally, I almost always buy OEM parts, but then again, I work in the Parts Department of a Toyota dealer.

 

We have had issues with oem parts and pricing lately. But somethings are definitely worth oem. Bearings especially.

Heck we ordered NSK Carrier bearing for tacoma and it only lasted 1 year. OEM lasts 15-20.

I watched OEM prices climb, especially after covid. Drives me nuts that an oil pressure switch was 48$ and now its 120$ in 5 years.

 

I agree with this. Something is causing the inner bearing race not to seat-up against the CV.

 

Which are in fact, cheap chinese parts. Mostly the same garbage that vatozone and advance auto sell. Napa is a re-boxer of crap parts.

The shop that fabricated new control arm mounting points, I'm hoping that made/used a locating jig of sorts? Also, did you replace the steering knuckle as well?
Maybe it's time to take it to body shop that has a frame rack and get everything measured, so that you can see what else might be bent. It's not out of the question for the frame to be twisted front to rear, based on the description of the landing.

 

Your steering knuckle is bent. The crush washer feel are the seals on the bearing getting bent. The 173 is for side bearing preload, you are not getting the proper preload and then the bearing easily slides out of the race within 5 miles and then you start to destroy it rather quickly with continued use. Did you check the knuckles with a straight edge? The frame is irrelevant, even if it is bent and wouldn’t contribute to the bearing failure. Tire wear on the other hand would be shit along with handling, but your steering knuckle is bent.

 

x2 knuckle. They are known to bend with abuse anyway, and you face-planted hard enough to bend the control arm. The issue with torqueing the axle nut gives solid evidence here.

 

@zippsub9: DING DING DING! You are correct.
I couldn't see the bend until I removed the knuckle from the truck.
I ordered a new knuckle and another hub assembly and finally got a chance to install them this past week. I can now confirm that the issue was a bent knuckle. If there is anybody reading this that is having repeated bearing-hub failures, I want you to know the following: A STRAIGHT EDGE WON'T NECESSARILY IDENTIFY A BENT KNUCKLE!
I thought I had the knuckle ruled out after installing bearing #3, as I had taken a straight edge to the bearing mounting surface at that time. I placed the straight-edge across each of the 4 sides of the mount surface, and saw no gaps. HOWEVER, if I had used a 2-dimensional straight edge (an "X"), I would have seen it not sit flat on all 4 corners. It would have rocked a bit, indicating that the knuckle was twisted. Although the amount of twist was significant, looking at the picture, you can imagine how a 1-dimensional straight edge would not be able to show it.
This was a very frustrating problem for me, and its finally solved! Goes to show that some of the most frustrating problems are sometimes caused by things you may have ruled out using insufficient testing procedures. Lesson learned, problem solved, happy ending.

 

Almost 2 months now since I replaced the bent knuckle, and wheel bearing shows no signs of any remaining problems. Still tight, quiet, and working as it is supposed to. So I am confirming again that replacing the knuckle fixed the issue, after putting a little time and miles on the new bearing.
I will also add some more closure to this topic by addressing more of the symptoms I listed in my original post. I mentioned how tightening the 4 hub mount bolts felt like there was a spring washer even though there wasn't one. It should now be obvious why it felt that way. And after replacing the knuckle, that spring washer feel was no longer present when I installed the new hub assembly. So if the last few turns of the wrench feel like you are compressing a spring washer, you might have a bent steering knuckle. I also mentioned not being able to torque the stub-axle nut beyond about 50ft-lb before the bearing started seizing. With the new knuckle and hub assembly, I was able to torque it to 173ftlb, no problem.
Now that that's all good, I can move on to my next problem: dealing with both P0420 and P0430 in California. For those who don't know, those codes mean I need to buy $3000 worth of upstream cats before my vehicle registration is due next year. So far, I've been taking this approach to dealing with that problem:

 

Po420
Or sneaking o2 spacers by a biannual