L400 hub bearing replacement (front). You have to use special grease for the hub bearings!

The L400 Space Gear is a great way to replace the hub bearings without the need for special machinery.

What is a hub bearing?

These bearings are used to turn the wheel smoothly.

In the case of this car, the disc rotor is rigidly attached to the hub by bolt and nut.

Since the hub is the part that puts the most weight on the car, the load on the bearing is also heavy, but the durability of the bearing is high and usually the part can last 200,000-300,000km without replacement.

Normally, 2 to 3 bearings are used in a car.

How difficult is it to replace a hub bearing?

Some cars require special tools or a hydraulic press, but this L400 space gear was done as a DIY project without any special tools.

However, if you order a new hub bearing, it comes with the outer race as well as the hub bearing, but the difficult part for me was replacing the outer race of the bearing (the metal ring that receives the bearing).

The inner side was press-fitted using the outer race that I removed, and the outer side was press-fitted using a large impact socket (for the truck) that I happened to have, but I don’t think anyone would normally have such a large socket, so the outer side may have more trouble press-fitting the outer race.

Remove the hub and rotor.

Jack up the front and remove the tire.

Remove the brake assembly. Put the calipers on the upper arm.

Remove the hub cap.

Remove the snap ring and O-ring in the shaft.

Turn 14mm 6 bars and remove the hub cover.

Turn the two screws securing the locknut anti-rotation bracket and remove both screws.

Turn the lock nut and remove it.

Once you have done this, you can pull out the hub with the rotor. At this point, the outer bearing should roll off the hub.

Remove the inner side oil seal.

Pry off the inner side oil seal with a flat head screwdriver to remove the inner bearing.

Since the oil seal is reuse, lift it up a little by little all the way around.

Once the oil seal is removed, the inner bearing can be easily removed, so I cleaned up the inside of the rotor in preparation for the next outer race removal.

The outer lace falls off if you hit it.

The rotor has dents on three sides.

Perhaps this is for replacing the outer lace? I used a thin metal rod and a hammer to carefully tap this area evenly in all three places to drop the outer lace.

Originally, the bar used for this work is called “brass bar”.

This time I used a steel bar, so I wondered if I damaged the inside of the rotor. After the work, I checked inside, but there were no scratches on it.

Insert the outer side inner lace.

The diameter of the outer side inner race is about 73mm.

Then if you have something cylindrical with a diameter of 70mm or 71mm, you can press-in.

I looked for it… and found it!

What a 50mm air impact wrench socket for big trucks!

Why do you have this stuff? As I thought about it, I put the outer lace in and slowly put it in, tapping it lightly with a hammer to avoid applying as much force in a biased direction as possible.

Insert the inner side outer lace.

On the inner side, the outer lace is about 5mm bigger than the outer side, so it’s not as big as it was before.

I couldn’t use the impact socket I used earlier, so I thought “what to do…”, but when I looked closely at it, it was too shallow, so I tapped it in with the inner lace I removed.

But if you just put the old outer lace in the new outer lace as it is, you won’t be able to get the old outer lace off.

I made a notch in the grinder so I could get the old outer lace off later.

Once the new outer race was firmly in place, I was able to easily remove it by tapping the old outer race from the backside with a steel rod.

The hub & rotor should be placed with the inside side up.

Grease up the new bearings.

Grease the inner and outer bearings with new grease. Please use “bearing grease”. I pressed the grease gun into the gap between the inner and outer bearings and squeezed the grease out.

So, to finish it off, I do a rubber hand and take the bearing in my hand and turn it in a slippery direction.

After putting the inner side bearing into the rotor, apply grease to the bearing again and smooth it with your fingers, then wash your hands with kerosene, and then install the oil seal.

Oil seal installed

I have a special tool for the oil seal as well, but I couldn’t bring myself to buy an expensive tool that I don’t think I’ll use in the future, so I used two hammers to get it in! Press down on the cleaned oil seal by hand. Place the flat part of the hammer against the oil seal and lightly tap it with the other hammer, inserting it as evenly as possible.

As long as the outside of the oil seal is the same as the rotor, you’re good to go.

This time, turn it over and insert the grease gun from the outer side and apply grease to the other side of the inner bearing.

Also, grease the inside of the rotor and the outer race of the outer bearing.

The locknut should be loosely tightened.

The rotor is put in and the outer bearing is put in, and then the lock nut is put in, but this lock nut is said to be difficult to tighten up or down.

The right way to do it is to tighten it with 20kgm to 30kgm, then loosen it, lightly tighten it, and if the screw holes in the lock washer don’t fit, move the lock nut in the direction of loosening….

Well, the bottom line is that it should stay lightly in place with no gaps in the rotor and outer bearings.

So I turned the rotor by hand while pressing down on the outer bearing and put in the locknut and lightly hand tightened it! Put the lock washers in, move the screw holes in the loosening direction, and tighten the screws!

I’ve assembled it this way many times before and I haven’t felt any problems with it. On the other hand, over-tightening the lock nut seems to be quite problematic.

Impressions after the exchange

It’s still quiet, after all.

Maybe it’s an inexplicable sound in a word that’s usually hard to recognize, but it’s clearly that kind of noise that’s gone.

The only sound in the car is the friction between the tires and the asphalt.

The ride quality has changed as well. The shock when picking up the gap has been eased. How can bearings alone make such a difference without replacing the shock absorbers and rubber parts! I also thought.(Quite an exaggeration.)

When I replaced the hub bearing myself this time, I felt that it was surprisingly easy!” That means.

The bearings are just in, the outer race can be removed and put in with a light tap, and the oil seal is surprisingly easy to remove and reuse.

A lot of cars have a bearing press-fitted into the knuckle, but to have such a simple structure and to have it last for 200,000-300,000 km is quite impressive.

It took me a long time to replace the outer race this time, but when I looked at the outer race I saw no signs of wear and tear, so if the outer race can’t be replaced by any means, could I just replace the bearings? I also thought.

Or would it be faster to take the L400 parts to the nearest repair shop? The labor rates don’t seem like much of a stretch.

If your car has over 200,000 miles on it, you should definitely change it. It will also change your ride quality. (Maybe I’m exaggerating quite a bit.)