[junior82]

Just ordered a new OEM hub assembly from a Nissan stealership to replace the front driver's side wheel bearing which is humming like an angry wasp.

I am quite pleased that the hub assembly is bolted to the steering knuckle instead of the wheel bearing just being pressed fit into it like my 2005 Toyota Prius had.
That Prius also needed a new front wheel bearing on the driver's side BUT that bearing lasted until 240K miles before it needed to be replaced.
My Altima's bearing lasted 'only' 120K miles. Could've hit a deep pot hole here in SE Michigan - there were oodles of them last Spring. I don't
recall doing so and the humming has just become noticeable the past two weeks. Wasn't humming on my 600 mile roundtrip to the Chicago area
three weeks ago - or at least it was just starting to hum and I just didn't notice it.

I watched a few YouTube videos and it appears that the four bolts attaching the hub assembly to the knuckle can be loosened without unbolting the knuckle
from the McPherson strut. I'm going to attempt this first as three of the four mechanics on YouTube showed it was possible to loosen those bolts without extra effort.

After a simple search I didn't find more than one example of anyone replacing a front hub assembly (DIY) on a 2013 - 2018 Altima.
Nissan made a change in 2019 in the 6th gen to the knuckle/hub assembly - maybe they cheapened the assembly and just pressed the wheel bearing
into the steering knuckle like Toyota did/does - that would be bad.

Anyway, if anyone has recently replaced a front hub assembly on their 5th gen Altima, I'd like to read your (horror) story if you did the replacement yourself.

I will be sure to share my experience with it if I run into difficulty which is almost a given for this DIY mechanic.
One reason is I don't own a beefy enough impact wrench to loosen the axle nut. I should at the least rent a battery electric one to make the job easier.

 

[junior82]

Run into difficulty? Oh hell yeah! What should've taken an hour took three. The main problem was rust after eight Michigan winters. The cotter pin in the axle shaft was difficult to remove, then the rotor, then the axle nut, and then the hub itself which took the most time because the steering knuckle is an aluminum alloy and the hub is steel. I was damn lucky the rust wasn't worse because I would've needed a puller or hydraulic press to get the hub out of the knuckle. And that would've required removing the entire steering knuckle which is not a big deal (unless rust had its say).

The YouTube videos make this look so easy - possibly because these were all southern or western US State Altimas not right by an ocean. It took 30 minutes of slowly knocking the hub out of the knuckle with multiple strikes with a 2 lb. sledge to get the sucker out. The main issue is the rotor dust shield (splash guard) is in the way on half of the hub. You can't rotate the dust shield 180 degrees to hit the other half straight on until you get the hub about 2 to 3 mm out of the knuckle around its entire circumference. Consequently, it was very difficult to knock the hub out of the knuckle with the dust shield in the way when you've got heavy rust.

I borrowed a Harbor Freight Earthquake 20V 1/2" drive battery electric impact wrench from a co-worker - thanks Dom. It had sufficient torque to break the axle nut free and loosen it off the highly rusted threads on the shaft. It appeared to be using almost the same amount of torque and impact to loosen the nut as it did to break it free. The axle nuts were not very difficult to loosen on my Prius and my two Civics and I did all three with brute force with a three foot long breaker bar. Doing this with a breaker bar would've taken me at least 10 minutes on the Altima That nut was on so f***ing tight because of the severe rust. I was lucky I didn't strip the threads. I think the impact wrench was helpful to prevent that.

I recommend getting a swivel socket for the four bolts that fasten/hold the hub from the back of the steering knuckle. I think it was a 17 mm but I'm not sure. You can get by without one but it makes the job so much easier.

Re-assembly wasn't too bad. I cleaned the rust off of the steering knuckle with a coarse nylon wheel from Lowes. That worked great. I used 60 grit sandpaper inside the knuckle bore to clean that up. The new hub fit perfectly but it was a challenge doing it alone as the rotor dust shield was difficult to hold in place to screw in the bolts on the back of the knuckle. Inserting the new hub onto the axle shaft to line up with the splines was easy. The axle shaft doesn't go all the way into the hub until you tighten the axle nut on it. I was a little concerned that I had lined up everything correctly but the axle shaft did enter the hub easily all the way with the Earthquake impact and with much less force than it took to get it off because of the rust. Quicker with the impact too.

So, all in all wasn't too bad just took more time than I expected because of all the rust. If you live in a southern or western US State where salt is not used on the roads, then this job would probably be an hour instead of three it took me.

 

[junior82]

Well, there would've been easier ways to get the hub out of the steering knuckle had I anticipated I would've had this much difficulty. Even though I like to think I've researched something enough, I more often than not learn I haven't. Again I was lucky that it didn't bite me in the ass this time. I no longer have a spare vehicle to use in case I f*** up.

There's one called a hub shocker that some swear by. It's somewhat crude and I believe using it could deform the bore in an aluminum alloy knuckle if struck with too much force, so I wouldn't use it.

You can cut off a couple of the studs from the hub, pop the stud stubs out and use bolts and nuts to try to push the hub away from the steering knuckle which looks like a better option than the hub shocker.

Sometimes there's no method that will work to free the hub from the knuckle with it still attached to the suspension, the knuckle has to be removed to press the hub out because the rust is so bad that the hub is seized and virtually welded to the knuckle like this example from YouTube. I'll admit I laughed a couple of times watching this guy struggle with this.

 

[npolite]

With any suspension work you really do need to get yourself a good set of impact wrenches. I started my build up of Milkwaukee M18s with the stubby and will get the mid-torque one when it goes on sale. The only reason I don't have a mid torque yet was HD had a sale on a mid for $100 and as they sold out they upgraded me to the high torque for the same price!

 

[junior82]

It's a little late in the game for me to invest in battery electric impact tools. I'll be 65 in January and my rheumatoid arthritis will inevitably make it difficult to do suspension repairs eventually. Right now I'm still capable but that could change quickly.