Prerunner Front Wheel Bearing WHY question???

I bought my 2010 DCLB Prerunner the last day of 2009.

Been on here a while, but not frequently lately.

Known about the failed bearings, and the guys that sell complete replacements.

Planning to do mine before they fail, so very soon.

Here’s the big question, on the Prerunner, the front hub is secured by a special nut that is peened to prevent it backing off. The torque on the nut is like 200lbft.

Why in the world do they press the bearings onto the hub? For years old school front wheel bearings, like in old school trucks and cars, simply dropped into the hub and everything slid onto the stub axle of the spindle.

Why didn’t Toyota design a no press fit hub to bearing clearance?

 

WOW where have you been in the last 40 years. They started putting this stye bearing on vehicles since the 70s maybe even earlier on the older FWD vehicles too.

You want an honest answer about the sealed unit bearings over those tapered roller bearings. Honestly it's ease of manufacture, maintenance, and getting a CV axle to drive the wheels. Personally as a mechanic I am glad every car on the market has gone to this style bearing less maintenance for the owner of the car, less mess, and typically cheaper in the long run. I have replaced far more tapered roller bearings and spindles due to lack of maintenance and keeping proper preload on those bearings thus smoking them and not just destroying the bearing.

If you really want and have the skill you probably just need the bearing and not the hub as well. You can press the hub out then into a new bearing. Are the sealed unit bearings more expensive yes, do they cost more to replace yes, last longer yes. Simpler and less complication for use in a CV driven axle oh yeah!!!!!! Your prerunner is based off of a 4wd vehicle so the front suspension has to be able to accept a CV axle. If I am not mistaken I know on the 1st gens maybe on the second gens the 5 lug has those beloved tapered roller bearings of years past.

To answer you last question for no pressfit hub to bearing is then the hub would spin on the inner race of the bearing and render this style of bearing useless.

 

Ok, thanks for talking down to me but whatever. Yes, blah, blah I have seen this style before.

Your last remark about the bearing race spinning on the hub, why is it that those ancient setups where the bearing slides onto the stub axle doesn’t spin, unless the bearing fails or goes dry, but now the bearings are pressed on. Why does it need to be pressed on when it is retained by a large nut?

BTW, I never complained about cost or inability to accomplish the task. Not an issue. You brought that up.

 

It's not fully retained by the bolt or axle stub it's preload is set by that. Also this style bearing vs the tapered rolling bearing the tolerances are a lot tighter. Try and spin a new sealed unit bearing by hand vey difficult. Tapered rolling bearings are very loose fitting so easy to spin and the nut and washer that retain them only contact the inner race thus pinching it to the spindle. The outer races of them are still press fit into a rotor or hub so they won't spin and only the bearing section will spin. Also the bearing design is different the unit bearings are typically sealed ball bearings and are not good at taking side loads being loose fit they require a press fit on both races and higher preload to stay together. Tapered roller bearings face opposite of each other and can take side loads better without a lot of preload and minor interference fit on the inner race.

You are looking at 2 completely different bearing designs you have to have a basic understanding of the physics and engineering behind them to grasp why they are set up and need different ways of attachment.

 

The Prerunner uses the same design as the 4wd, minus the bored spline and special nut retaining the hub. According to info posted here for years, and a recent video I got for this style hub, there are no ball bearings. The bearing assembly uses two tapered roller bearings.

Watch the video, and explain where these ball bearings are...

Again, lower the effort to talk down to me.

https://m.youtube.com/watch?v=WOSrVIFdSvc

 

Anyone else here care to discuss this in a civil and knowledgable manner. This guy Skip, ovrindkull is pretty clueless about these wheel bearings, let alone the logic of pressing them on the hub.

 

Sounds like you'd be more happy with an old farm tractor, better leave this new space age stuff to us kids

 

And ironically, the space age stuff actually uses tapered roller bearings that are not pressed onto the shaft.

The reason behind not press fitting tapered bearings is that by design they are set to the proper preload by torquing the nut. If you ever had a pinion gear removed, you know when you reinstall it, the pinion shaft slides through the bearing race, and you tighten until a certain amount of resistance on the pinion shaft is obtained.

That other guy, the self proclaimed expert, thinking there was ball bearings in there.

 

Pretty sure they are ball bearings in there, its a one piece outer race and a two piece inner race. The hub is a press-fit through the two inner races to hold them together. On a four-wheel drive, the axle end goes through the whole thing and the axle nut holds the whole deal together. There's no adjustment needed or required because the two inner races are side-by-side touching and everything is clamped together.

The older style tapered bearings were loose fit, susceptible to getting dirt and contaminants in them, required constant service, and depended on your proper tightening of the castle nut to get the preload right.

 

Watch the video I linked, Prerunners have tapered roller bearings.

 

Because they dont want the two halves of the inner race to shift around and they dont trust you to torque the axle nut properly?

 

Sounds like you're the expert go talk to the Toyota engineers. Go buy a 1st gen 5 lug truck it has exactly what you are looking for, maybe the 2nd gen 5 lug trucks are like that too.

He doesn't like this answer this is just a complainer like the guys who still want carburetors around. Useless to try and explain anything of this system to him because he already knows it all and apparently thinks toyota is stupid for making a 2wd based off of a 4wd with interchangeable parts.

 

I really need to disagree with your statement. Older tapered bearings sealed better then the newer style ones do. I repacked mine about every 50K and never had one fail save one and that was because the actual spindle broke [don't jump your FJ 40 kids] which wasn't the bearings fault. Contamination is much easier on newer bearings and unlike the old ones, you can't easily remove them, clean them up and repack them and install new seals. Setting preload is stupidly easy once you do it even once.

I understand why they changed the style [cheaper and faster to build the vehicle] but they are not ''better'' in almost any other way. IFS doesn't prevent any problems with using tapered roller bearing that can be repacked.

 

The only downside.......it's messy and your face always seems to itch just as your hands are full of grease and bearings. I just wear latex gloves when I do it.

 

You would need a hub set up like the locking hub assemblies which adds more parts and complication to manufacturing that's the key to this whole thing they are wanting to simplify manufacture and bring things down into as many sub assemblies and quicker assembly as possible.

Personally I like the sealed bearings a lot better than the old tapered roller bearings not because of the mess as I have a bearing packer where I don't get greasy really. But they come out of adjustment/preload fairly often the dust cap isn't full proof nor is the back seal. The newer bearings I haven't seen near the contamination in them when taking apart as I did in the tapered style.

 

Bearing problem in a damn near 10 year old prerunner? You don’t say...

 

Hey OP, sell the prerunner and go buy an old f150 with repackable bearings. Have fun with that...

 

A little piece of automotive joy died out when the sounds of the 4bbl secondaries kicking in faded away...

Back to original programming...

 

Nothing to add but using an impact vs manual strength to remove that WB nut will prevent a change of underwear and several restroom breaks expecially with the consumption of beer and taco bell prior to install. And yes, ....TB was worth it.