4Runner wheel bearing vs. Tacoma question

But I mean wheel bearings shouldn't be something that you have to replace on a regular basis right? I could see it if I was out every weekend hitting some rough stuff but my truck is sadly a pavement princess lately (something I am hoping to change now that my son is getting a little older).

 

Now imagine having to press out wheel bearings every time you replace brake rotors, which is exactly what happens on the Colorado/Canyon.

 

I see what you are talking about now. I don't know the answer as to why Toyota indicates using NSK for the Tacoma replacement. I can assure you that KOYO is certainly the best quality in wheel bearings. That is why I only build my assemblies with KOYO brand. they do fit exactly the same across all manufacturer lines as I showed in a previous post in this thread I believe. I have less than a 1% failure rate within 100k miles. of those over 100k with my assemblies, I have not had a failure that has been reported to this date. This is also why I feel KOYO is the way to go.

Always a good idea to research of course, and when a question arises, ask!

 

Wheel bearings have had to be replaced periodically on vehicles since I can remember. It is a commonly failed part. Less so these newer model years as the design has shifted to this module design for many manufacturers. That being said, parts fail. That is just the way of the world. Toyota has been a industry leader in quality for sure, but their service department has been just as busy as the other manufacturers service departments since I was a kid. The big difference now is with Internet and social media, people are discussing it in larger groups. lol

 

Not just those! thousands of manufacturers have the bearing race pressed into the brake rotor! dealt with those for years!

 

Yep, I know Dodge and Chevy does.

 

Toyota used to on many of their pre-2000, and still does on the Tacoma 5-lugger!

 

Periodically like maybe every 100,000 km hopefully right?

 

In most cases, yes it is usually over 100k before wheel bearings typically fail more consistently.

 

[QUOTE="BamaToy1997, post: 13833385, member: 71846" ...That information is not accurate. The FACTORY OEM bearing for the 4Runner, Tacoma, FJ Cruiser, and Lexus is Koyo. NSK, National, and other brands do make aftermarket bearings that are called "OEM" but only in the sense that the bearings are built to factory specifications and require no modification to install them.

I would like to see the information supporting this. I have been dealing with the manufacturing plant for Koyo for many years, and there has been no changes to the manufacturing process for these specific bearings.[/QUOTE]

Her is the information I provided in another forum. I purchased two of the new part number from a Toy dealer as soon as they appeared and both are inscribed on the outer race as NSK. http://www.toyotanation.com/forum/6...aring-improved-oem-bearing-now-available.html

 

In bold is a large factor in wheel bearing failure on vehicles with double row unitized style wheel bearings like these. With wheel spacers or wheels of different offset, the weight of the vehicle puts much larger axial load on the bearings, instead of radial load, essentially overloading the bearings. Because the two rows are so close together in a double-row bearing, the effect is amplified over an older style like your 4Runner with two tapered roller bearings much further apart. Think leverage between the two rows, and your wheel spacers are your lever.

That said, a lack of lubricant was obvious when I replaced mine, the lips of the inboard seals were burnt from friction, as there was no grease in the space between the bearing unit and the seal, so nothing to keep the seal lubricated. Both sides were contaminated with water, as a result of the seal failures. I packed some wheel bearing grease in that area to prevent a repeat.

 

...cont. from Post #30 above. The two OEM front bearings I purchased for the Taco, Part No.

$172 43570-04011 Axle Bearing Assembly, Front

43570-04011, have this inscription on the race: Japan Y NSK 54KWHD0(O?)1J. Each has one more roller and the rollers are different size as compared to the KOYO as mentioned in the link.

 

Yeah I figured that having the spacers and bigger tires are definitely a huge factor but should be similar effect as having different rims with the bigger offsets right? I mean there's a ton of guys running lifts and bigger tires that aren't blowing through wheel bearings way quicker than expected right?

 

Spacers or offset wheels have the exact same effects on the bearings, you are right there. It's a big factor in bearing life, but not the only one.

The easy way to determine WHY a bearing failed is to examine the failed part though, which did turn up very little grease with water contamination and resulting rust pitting in the races if the bearings.

 

How do you know they have more rollers? They would have to redesign the rollers as well as the cage, and race to do this. Do you have any breakdown in this information? Personally I have tested NSK bearings for this application, and found them wanting.

 

I have new sets of both the older part number ending in 10 (KOYO) and the newer ending in 11 (NSK). I separated the two halves by removing the center plastic collar that holds them together and counted/measured the rollers. There is one more roller in the NSK in both halves and the rollers are longer than the KOYO. Looks to me like the weight would be better distributed in the NSK.

 

Pics?

 

No, I just repacked them and put back in cold storage. Maybe later I can get around to it. They look exactly like the other old KOYO bearings only they have one more roller in each half and the rollers are longer, and they are imprinted with NSK. Still have a minimum amount of grease.

 

I too would like to actually see this. NSK bearing manufacturing website doesn't show this. Either way, NSK never stood up to the testing I did when I was making my selection for parts. With less than a 1% failure rate with my KOYO assemblies, I'll stick with them.

 

Had a customer bring this back up (New design bearings) and I thought I would pop this back up. My research shows that this supposed "new design" just can't be true in the form design listed. (i.e. 21 rollers instead of 20 rollers) Below is my explanation why I say this is not accurate:

The housing itself would not be able to be changed. The external dimensions would have to be the same as original so that the bearing would still fit the same seal, o-ring, hub, etc. So in order to put 21 rollers inside the rollers would have to be smaller in diameter. If they were smaller in diameter they would no longer fill the gap between the inner race and outer race so they would have to redesign the entire inner race and outer race, as well as the depth since these rollers are supposed to also be longer.

The ABS system as well as the speedometer would be confused and/or inaccurate with 21 rollers. Why? Because the ABS sensor, which feeds the speedometer data on the Tacoma, sends 20 pulses to the ABS sensor per revolution of the wheel. If you installed a bearing with 21 rollers then the ABS computer as well as the ECU would be receiving incorrect number of pulses-per-revolution. This would bean that if you replaced the front bearings with a 21 roller unit, the computer would think the front wheels were turning faster than the rear (21 pulses in front to 20 pulses in rear) so the ABS system and speedometer would be confused. Not to mention how confused it would be if you had replaced the LEFT assembly with a 21 roller unit, and left the original 20 roller unit on the right. (contrary to old design that used the transmission output speed sensor for the speedometer, the Tacoma currently uses that data for transmission information and diagnostics, and uses the ABS sensor data for vehicle speed)

It is for these reasons that I don't see a redesigned bearing having 21 rollers in it working. It would not only force owners to replace BOTH front bearings if one were to go bad, but it would ALSO require the ABS computer and ECU to require reprogramming for the different number of pulses. Not to mention that Toyota Uses Koyo as their bearing manufacturer, not NSK, which is a totally separate brand in the first place. If Toyota wanted a redesigned bearing, they would have Koyo do it.