Rear Wheel Bearings

Hi, all ---
Long time no see! Last topic was the infamous 2004-2006 double-cab brake master/"unicorn"/booster assembly. Finally got that one worked out OK, located & bought the assembly, working fine now.

NEW TOPIC: rear wheel bearings. I had new bearings installed when I bought the truck in 2018. They failed about 20K miles later, in March 2023. Unfortunately, I don't know what brand they were. I replaced them with new Toyota OEM bearings, with me doing all the work except for the press work which I farmed out to a local machine shop. The whole process went smoothly, and I felt really good about the installation. Then, BIG surprise, the new ones failed near the end of a 2500 mile trip last week, resulting in a big, fat tow truck bill. Total mileage on the new bearings was less than 5,000 when they failed.

I now have to replace these bearings AGAIN!! My question: what are your feelings about the best brand of bearings to buy? Timken is a pretty well-known brand, and I have had good luck with SKF in motorcycles. There are quite a few low-budget brands out there, and I don't know what their track record is in terms of durability and service life. I don't know who supplies the Toyota OEM ones, but would expect them to be a good, reputable company.

Please provide your input on the best, most durable brand to buy. BTW, my truck has a camper on it that weighs about 1300 Lbs. Obviously that makes life a little harder for the wheel bearings.

Thanks for your help.

 

SKF fan here. Always had good luck with their bearings in all sorts of equipment, machines, and vehicles. Just put SKF greasable u joints in my truck last month and trashed the non greasable OEM crap.

 

Are they doing the press work right? It's a very small window the retainer needs to sit in. If it's pressed to far the tube seal will let diff juice into the bearings.

 

Something is wrong here. I would be trying to figure out why they keep failing. OEM bearings should last a long time. Hopefully others have some ideas.

 

Oem is the way to go, it sounds like you might have some other issues if they are failing that quickly. Do you tow a boat at all? Possibly look at new backing plates or axles

 

Live fast, die young

 

So the camper is 1300 alone? Then you start adding all the goodies, water, tools, etc? Pretty soon you have a 2k load full time. Y or N?

 

I'm going to guess @bmf4069 summarized the problem succinctly with his reply.

 

Thanks to everyone - wow, this is truly a rapid-response team! I'll try to hit each person's input in this reply:

• Yep, I have never had a complaint about SKF. I tend to be a fan of Swedish stuff - they generally do it right. I have a Swedish chain saw that's 46 years old, still runs and cuts as strong as it did brand new. I'm guessing it has SKF bearings in it! And (a little pat on the back, please) I have done meticulous maintenance on it for all these years and it's paid off.
  
• 
  
• I felt good about the press work. I was right there with them, and I'm super-picky about the details. The bearing, first retainer, circlip, tone ring, and second retainer were right where they belonged. At final re-assembly, I double checked the alignment of the tone ring with the wheel speed sensor, and the position of the second retainer with the garlock seal --- everything was spot-on, which was part of the reason I felt really good about the whole exercise. And you're totally right, the positioning of the inboard retainer relative to the garlock seal is critical, with little or no margin for error. I saw zero evidence of diff oil leakage before the "catastrophic" failure.
• 
  
• I agree that it's wise to consider some higher-level issue that might be contributing to the premature wear. I've driven the truck for 5 years now, and no obvious issues have shown up. I'll do some head-scratching and see if I can think of anything else, though. Like most used-vehicle buys, this one was a total crap-shoot, with no information or records concerning maintenance history. I don't know if the truck was ever wrecked or not, but suspect it was, based on some fairly new-looking suspension parts in the front end. It's the classic case of "pay your money and take your chances".
• 
  
• I don't tow a boat or anything at all. The backing plates and bearing retainers look good. I don't see any detectable runout or "wobble" at the hub, either radially or axially, nor do I feel any weird vibrations or erratic behavior. Also, the backing plate / axle assemblies fit into the axle housings and bolted up smoothly, with no indication of binding or misalignment.
• 
  
• The camper "bare" is about 1,100 Lbs. With a full load of water, food, etc. I figure it's around 1,500. Definitely approaching the "3/4 ton" weight limit, but I don't think it's going over that.

• I've already missed my window of opportunity for dying young! I'm now approaching 80, but still going strong and enjoying life. Like a birthday card from a friend said: "Growing old is inevitable. Growing up is optional".

​

So - lots of great questions and observations. Many thanks to everyone for the quick response and the thoughtful and helpful replies. I will keep an eye out for further comments & suggestions. And, I think I will buy SKF bearings this time around.

Cheers to everyone, and thanks!!

 

Gave it some more thought.....It doesn't take much to chew through seals on mechanical shafts. I'm thinking maybe you have more roughness than you think on the axles. Not poking fun at old age, but I have noticed that in my own life, my failing senses aren't anywhere close to where they once were. At close to 80, you just might simply be much like me and just don't have the sight and touch senses that you think you do while analyzing the condition of the seal areas. Not saying you don't know what you are doing, just saying it's something to consider. I will tell you that I actually had it happen to me on a different piece of equipment, but it was still a shaft, seal, and bearings that failed prematurely multiple times until I threw in the towel and bought a new shaft. That was the end of having to buy parts, tear it down, scratch my head, reassemble, and repeat. My fingers are just too damn old and worn the hell out to feel properly anymore, and when coupled with poor eyesight it can be catastrophic sometimes. Might be something to think on.

 

Left is correct, right is too far. 5mm in the view port on the retainer.

 

I’d say we were of maybe 1-2mils when we did mine on the passenger side after Sedona/cinders. So far so good.

 

Hello again ---

2mchfun --- Thanks for the additional thought, I appreciate the extra time and effort. Agreed, things don't quite work now as well as they did 30, 40, 50 years ago. And you're right, surface roughness can definitely contribute to seal wear. That said, the sealing surface for the Garlock-type seal at the end of the axle housing is not the shaft itself, it's a pressed-on spacer which I replaced with a new OEM part as part of this job. Hopefully, this spacer is within spec in terms of surface finish. Also, diff oil that's leaking past that seal will show up as a leak onto the garage floor, and the brake shoes will be affected. The photo from bmf4069 shows this very nicely. Starting at the bearing in this photo and working upward (i.e. inboard on the truck), you have the bearing, then a spacer, then a circlip (not visible in the photo), then the ABS tone ring, then another spacer which isn't actually a spacer at all, it's the sealing surface for the Garlock seal. Both spacers are the same identical part number.

bmf4069 --- again, thanks for the "extra-mile" effort. Your photo shows the incorrect and correct configurations very nicely. In the assembly at the right, the inboard spacer probably does not engage the seal at all, and would leak profusely. The assembly on the left is correct. There is a visible gap between the outboard spacer and the tone ring, and I suspect the tone ring is nicely aligned with the bore that contains the wheel speed sensor. I managed to locate a drawing in the Toyota Service Manual, which showed a 3 mm. dimension from the inboard edge of the spacer to the end of the machined (or ground) diameter on the shaft. You mentioned a 5 mm. dimension, which is probably just fine. On my installation, I put some dye on the sealing surface of the spacer, then assembled everything onto the truck and rotated the hub a few turns, then took it all back apart and verified that the seal contact fell right in the middle of the sealing surface of the spacer. I had to do some minor tweaking of the spacer position to get that contact to the exact location where I wanted it. My final dimension was approx. 4 mm. I had absolutely no evidence of diff oil leakage until my bearings gave up the ghost. Also, my tone ring was very well centered to the wheel sensor, with no ABS light or other brake issue.

I have previously read some threads that mentioned both ABS problems and diff oil leakage problems after a bearing replacement. Unfortunately, some shops don't do their homework, and assume that pressing everything together all the way is correct - just like the assembly on the right in your photo, where everything is sorta squashed together. In this condition, the tone ring won't align with the sensor correctly, and the sealing surface won't engage the seal lip correctly, it at all.

Nice job - thanks very much.

p.s. Is that a Vevor bearing removal tool that I see hanging down from your press? I bought one of those recently, and it works very nicely and saves a lot of time and frustration.

 

Alright. I had some similar thoughts about oil leaking. But I also have never worked on one of these assemblies so I don't know enough about them to say either way. I was just guessing maybe it was a small leak and maybe you weren't looking at the backing plates very often. Was the heavy load on the truck when it went 20k prior to failure? Have you added to the load or changed tire sizes? Maybe just bad parts. I'm wondering about material shortages and substitutions. Toyota has had unexpected bearing failures on crank bearings in the newest trucks. Kinda makes me think that their bearings manufacturer may have been taking some shortcuts at some point. Who knows, could be. Not sure what else to say without enough experience on the particular assembly. Might be able to unload everything except the camper and hit the scale, then load and hit the scale. Hauling heavy around the house now and again is one thing, but putting all that friction on those bearings for extended periods is quite different. Again, just something to consider. Good luck!

 

On my truck; I think the outer seal failed, the inner seal held the gear oil fine, but where the backing plate meets the axle housing(outer seal) had failed, my rust and moisture was only isolated in the outer part of the axle, right where the bearing is. The old seal definitely didn’t look great but wasn’t trashed. I think the handful of times I took the boat up a high grade and dipped her in deep, is what probably seeped water into that outer raceway, then slowly destroyed the bearing. We only changed one side, but the job wasn’t bad even in a driveway type shop(good buddy was willing to help)

 

Original front wheel bearings were mfg by Koyo. They make these for the rear.

https://www.yotashop.com/brands/KOYO.html?page=2

 

Yup, sounds like you got your pressing good. I forgot who makes the tool, got it off scamazon a few years back. It's the 2 piece Toyota axle tool.

 

That may be, but tell us more about that hotrod in the background!

 

Ha! I'm not sure what it is. The shop I was doing that at has all kinds of cool shit around there. They had a gt500 up on the lift and a c6 vette with a blower sticking out the hood. One of the other owners has a 70s Nissan p/u, and there's a Bonneville ssei outside. All kinds of unique and interesting things there.

 

DesrtRat,
You may have mentioned it previously and I missed it, but were the seals used Toyota OEM? Also have you removed and replaced the vent cap?

 

Clogged rear diff breather is my guess as well. Cheap and easy replacement.

 

How did bearings fail? Meaning what were the symptoms that alerted you to the failures?

 

Hi again,
To the three most recent comments:

• Yes, all seals, spacers, tonering, bearings etc. were Toyota OEM. And no, I have not looked at the vent cap, but now that the two of you have brought it up, I definitely will! I hadn't thought of that at all.

• I realized that the bearings were getting ready to cause trouble when I started hearing the low rumbling & growling sound from the rear of the truck over a period of a couple of hours. The actual failure happened about 150 miles from the end of a 2,400 mile road trip, with no camping gear in the camper - we were just using it as a truck on this particular trip, not camping. Shortly before what I would describe as a catastrophic failure, the noises from the rear started getting noticeably worse, and finally the driver's side rear wheel just about locked up, and diff oil starting leaking out rapidly. That was all she wrote. We spent about 2 hrs. on the side of I-70 in Utah, temperature 107 degrees, waiting for the tow truck.

I haven't torn into it yet, but plan to within the next few days. I'm keeping fingers crossed that I don't find any damage to the inner surfaces of the axle housing, like possibly from the tonering and/or inboard spacer hitting it, and I fully expect to find the bearing pretty much shredded. May also find some brake damage, dunno yet. We'll see what awaits! I'll update this thread once I see what's there.

At this point, I've gotten 20K miles out of one set of bearings, and less than 5K out of another. In neither case was there any indication at all of oil leakage, until the "catastrophic" failure that probably damaged the inboard seal when everything became very sloppy due to the bearing coming apart.

I'm starting to wonder if maybe I made a mistake by putting this fairly heavy camper on a Tundra truck. Interestingly, the bearings in the Tundra are the exact same Toyota P/N as those in a Tacoma. This causes me to wonder if maybe the Tundra setup is just a little too light-duty for this heavy of a camper. Possibly I would have been better off with a 3/4 ton GM, Ford, or Ram truck. Oh, well - 20/20 hindsight!! All this will become moot before long, as we plan to sell the camper and keep the truck sometime in the near future.

Thanks for the helpful comments. Cheers to all.

 

... I'm wondering if maybe you bought online and got fake parts (ebay, Amazon, etc).

If you bought at a dealership then something else is a problem. If the inner axle seal failed and gear oil got to the bearing and soaked it, that also would cause a failure.

Unusual otherwise.

I don't recall exactly what the load rating is for our trucks but 1300lbs may be a couple hundred (or more) over it.



As far as brands: koyo, nachi, nsk, ntn, in that order (all japanese mfg, commonly used by Toyota iirc). Timken is now owned by koyo but a good brand. Skf is also decent from what I can recall.

 

Hi,

Well, fake parts can be a real concern, especially when buying from unknown suppliers online. However, I bought these parts in person at the Toyota dealership in Durango, CO. Even buying "good" OEM parts, you never really know if possibly Toyota's bearing supplier may have changed something about their materials or processes. My background is in aviation and manufacturing of critical aircraft / defense / aerospace components. In that industry, once a given part design, materials, and processes have been qualified and approved, changing ANYTHING takes pretty close to an act of congress. I always have a healthy level of skepticism about the integrity of stuff I buy, even when it comes from well known and reputable suppliers.

And yeah, I'm getting more and more concerned that I simply made a bad decision by putting this heavy-ish camper on a Tundra instead of a good, beefy 3/4 or 1 ton truck. The "bare" weight of the camper is around 1,100, and I'm sure a full load of water, food, camping gear, etc. brings that closer to 1,500 Lbs. or even more sometimes. That may just be a bit too much for this truck.

Thanks for the comments.
DsrtRat

 

That's an unusual failure, and not one I recall hearing about before. You make a good point about the axle sharing parts with a Tacoma. It's a reminder that these trucks, while wonderful for what they are, are not half ton trucks like those from the big 3. I think you may be right that your camper is too much load for the Tundra.

As to which brand of bearings, I can say this: when I did mine I initially bought an SKF bearing. Then decided it was a safer bet to go with OEM, so ordered from one of the Toyota dealers that sells online. What showed up was a bearing in a sealed Toyota plastic bag inside a sealed Toyota box. And it was the exact bearing as the SKF. They both said "NACHI JAPAN" on them. So it's safe to say that SKF and Nachi are OEM suppliers.
EDIT: I forgot I had this pic in my gallery. The top bearing is the one I removed, the bottom is the SKF. You can see the words "Nachi" and "Japan" embossed on the seal. The Toyota part was exactly the same.

 

The top bearing says “China” on it.

 

I zoomed in and thought I saw the same thing.

 

Correct. That's the one I was replacing.

 

Hi, Folks ---

Tore into my driver's side wheel bearing this morning. Pretty much what I expected - the bearings were in pieces, and the tone ring and ABS wheel speed sensor were fubar'ed - see attached pics (no pic of the speed sensor - it looks even worse than the tone ring). The inner oil seal was also torn up. Fortunately, no damage to the axle housing, so I can breathe easier about possibly having to replace the entire third-member. Brake shoes were also covered with diff oil. Pretty much a mess, but not as bad as it could have been. Looks like time to order parts and head back to the machine shop for the press-off & press-on work. Once I get everything back together and road-ready, I plan to remove and store the camper and then advertise it for sale. If we ever buy another camper this heavy, we definitely will look for a more capable 3/4-ton truck. Til then, we plan to just enjoy this nice Tundra as a daily driver truck, hauling some tent-camping gear occasionally.

Note the bare machined surface of the shaft, that shows above the inner spacer. The distance is 3 - 4 mm. The lip of the oil seal hits right in the middle of this sealing surface, and the tone ring is nicely centered with the bore that the sensor fits into.

Thanks to everyone for the very helpful and thoughtful comments.

Cheers --
DsrtRat