Does the CV axle keep the hub tight or did I mess up wheel bearing replacement?

[Steve240]

Last year, about 20,000 miles ago I did a front end rebuild. At the time I replaced the front wheel bearings. I have recently noticed that my front hub assembly is very loose, with the truck jacked up there is a lot of side to side movement. I notice when I push on the hub I can see the back of the CV dust cover move away from the spindle.

What I Cannot remember from the job is if the hub should be tight before the axle nut is installed or is the CV shaft and axle nut that keep the whole assembly tight?

I tired loosening off the nut and retightening it but that didn't make a difference.

If the cv axle doesn't keep the assembly tight then I am guessing the bearings are toast?

 

[19963.4lsr5]

I haven't done the 4Runner yet but everything else I've got or had the hub part was pressed into the bearing.


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[mtbtim]

Last year, about 20,000 miles ago I did a front end rebuild. At the time I replaced the front wheel bearings. I have recently noticed that my front hub assembly is very loose, with the truck jacked up there is a lot of side to side movement. I notice when I push on the hub I can see the back of the CV dust cover move away from the spindle.

What I Cannot remember from the job is if the hub should be tight before the axle nut is installed or is the CV shaft and axle nut that keep the whole assembly tight?

I tired loosening off the nut and retightening it but that didn't make a difference.

If the cv axle doesn't keep the assembly tight then I am guessing the bearings are toast?

The hub is pressed into the bearing. The axle nut just holds the CV axle firm onto the hub. That axle nut has nothing to do with keeping the hub tight. Sounds like the bearing is toast.

Here's a video of doing the press work on some Tacoma Non-ABS Manual Hub Knuckles that is a similar job to doing it on A.D.D. knuckles with ABS. It's a video of doing the press work and swapping the knuckles to convert a 3rd Gen 4runner to manual hubs.

<iframe width="560" height="315" src="https://www.youtube.com/embed/TZ2sOfVrnhU" frameborder="0" allowfullscreen></iframe>

 

[nobb]

The purpose of CV axle is to transfer force radially to the wheels, never axially. On some designs, the torque of the CV axle nut to the wheel hub is important for setting the correct preload on the bearings. I don't believe this to be the case with the 4Runner's sealed front bearing design.

 

[Steve240]

Thank you for posting the video. It was good up until the point when they threaded on the locking nut to the hub and set the pre load.

In the case of the ADD hub there is no locking nut it is a collar that pressed on.

I am thinking that this collar, FSM calls it a bearing spacer, is where I messed up and I did not press it on far enough so it backed/walked it's self off along the shaft of the hub.

Do you know if it should be below flush with the end of the hub? Mine is currently sitting proud of the back of the hub by 2mm or so.

I have my spindles off so I am going to try to pressing that spacer down further on the hub and see how it feels. The bearing still rotates smoothly even with the free play.

 

[12BYotaFan]

The purpose of CV axle is to transfer force radially to the wheels, never axially. On some designs, the torque of the CV axle nut to the wheel hub is important for setting the correct preload on the bearings. I don't believe this to be the case with the 4Runner's sealed front bearing design.

It was my understanding that the cv nut torque setting was important to properly preload the wheel bearing? Thats why getting exactly the 174ft-lb is important. Every CV replacement thread or how-to across the web says its important for bearing life.

 

[mtbtim]

It was my understanding that the cv nut torque setting was important to properly preload the wheel bearing? Thats why getting exactly the 174ft-lb is important. Every CV replacement thread or how-to across the web says its important for bearing life.

Hmmm, maybe the CV axle nut does more than I thought on an ADD system.

 

[mtbtim]

Thank you for posting the video. It was good up until the point when they threaded on the locking nut to the hub and set the pre load.

In the case of the ADD hub there is no locking nut it is a collar that pressed on.

I am thinking that this collar, FSM calls it a bearing spacer, is where I messed up and I did not press it on far enough so it backed/walked it's self off along the shaft of the hub.

Do you know if it should be below flush with the end of the hub? Mine is currently sitting proud of the back of the hub by 2mm or so.

I have my spindles off so I am going to try to pressing that spacer down further on the hub and see how it feels. The bearing still rotates smoothly even with the free play.

Reading the FSM, it says to install the ABS Speed Sensor Rotor/Spacer and then install the Bearing Spacer with a press. It doesn't give any measurements so I'm assuming it's pressed in as far as it will go pushing the ABS gear against the bearing.

 

[Steve240]

It might make sense that the bearing spacer should be flush with the hub and then the cv holds it from backing out.

unfortunately I just tired to press the spacer down further and it won't budge, hit 20 tons on the press. I am starting to lean towards hitting up the wreckers and hoping to find a low mileage set of hubs.

 

[JRZEE2000TR4LTD]

Everything between the CV to the axle nut is "sandwiched" together. The torque of the axle nut just holds it all together. It's not necessarily preload because when you preload a bearing you apply a certain amount of torque or turns and then back it off a little. If the torque on the axle nut is too loose then the bearing could go bad early.

To the OP, if your talking about the spacer next to the ABS ring, that is not "pressed" on. It, along with the ABS ring just pop on the hub. Once they are on they freely move. But once the axle nut nut is torqued it should lock it all in place.

Here's a write up I did on the bearings.

http://www.toyota-4runner.org/3rd-gen-t4rs/228427-3rd-gen-front-wheel-bearing-write-up.html

 

[mtbtim]

Everything between the CV to the axle nut is "sandwiched" together. The torque of the axle nut just holds it all together. It's not necessarily preload because when you preload a bearing you apply a certain amount of torque or turns and then back it off a little. If the torque on the axle nut is too loose then the bearing could go bad early.

To the OP, if your talking about the spacer next to the ABS ring, that is not "pressed" on. It, along with the ABS ring just pop on the hub. Once they are on they freely move. But once the axle nut nut is torqued it should lock it all in place.

Here's a write up I did on the bearings.

http://www.toyota-4runner.org/3rd-gen-t4rs/228427-3rd-gen-front-wheel-bearing-write-up.html

Thanks for that description John. Now, with manual hubs with that locknut with the high torque spec, I think 203 ft-lbf,, [MENTION=148218]JZiggy[/MENTION] told me that lock ring is preloading the bearing. So, it would make sense now that I think about it that the axle nut for the CV axle is preloading the bearing. What do u think?

 

[Steve240]

That is an excellent write up you posted. too bad I wasn't able to find that using the search.

With what you have posted would you think my bearing is gone and cannot be repaired?

I can't remember exactly how I did the press work the only thing I think I could have done incorrectly is not supporting the bearing while pressing in the hub but supporting the spindle instead. I am hesitant to purchase all new parts and try this again.

 

[JZiggy]

Here's a little something about bearing preload from one of my textbooks. I'm pretty sure on ADD trucks the axle shaft does in fact preload the wheel bearing.

Since these tapered wheel bearings are complete units they preload differently from older trucks where you pregreased the bearing race, popped it in and torqued/untorqued to set the preload. My 1st gen was like that.