hey everyone, im going to be replacing my wheel bearings in the next month and would like to know how hard it is? im not going to buy the pre made kit from mazda trix, thats just too much money! has anyone here done this?(bearing removal, repacking and install?) any help would be greatly appreciated. thanks

Gabe

 

I'm tempted to think you're talking front bearings 'cuz you mentioned "repack". Please confirm.

 

I'll assume front too... you can get the bearings from NAPA or the like for pretty cheap.

But first, let me ask you why you think you need new bearings? Do they rumble? Or are they just a little loose?

The reason I ask is that replacing them is a royal pain in the ***. You have to dremel slots on the inside of the hub so you can tap (read: smash and ruin several punches) the races out.

If they are loose, you probably just need to tighten them up.

Here's my trick:

get to the nut
snug it down w/o too much force
spin the wheel
snug it again
repeatedly spin and then snug until it no longer moves with light force on the nut
too much force will damage the bearing
re-install castleated cap and new pin

fc3s.org used to have a article about this. What's with their website now?

 

yeah its the front wheels. the reason i say this is because i can grab my wheel and shake it.(grab from top of tire and move it back and forth) i read the write up on mazdatrix and it looks like a pain in the ***. would making the bearing tighter really work. i mean it is 20 yr old bearings.

 

Then you don't need a new bearing. Mazdatrix just wants to sell you parts. Tighten the bearing.

I do this for a living on all kinds of RWD vehicles. A bearing isn't worn out unless it rumbles when spun on the lift or when vehicle is at speed.

If you still don't believe me, you can at least agree that it's worth a try since the alternative is a nightmare.

 

http://mazdatrix.com/faq/frontbrg.htm

 

_

 

If your going to do anything with them at all, then at least take them apart and repack them with grease before tightening them up.

Bearings on a car this light would easily last 300K plus miles if repacked with quality grease ever time the front brakes where done or every 50K miles.

 

And weren't stored for the better part of a year every year like we in Canada are forced to

flat spots suck

 

Front wheel difficulty = 2 out of 5. Piece of cake, but instructions help. Rear wheel = i dunno.

 

pull them out... clean them up... inspect them... repack with quality bearing grease... tighten the retaing nut to about 20ft/lbs to "seat the bearing", then loosen and re-torque about a turn 3/4 to 1 turn so there is no play in the hub... not too tight you want just a little resistance without play

bearing and race should be smooth and free of bur's or grooves

 

Clean, repack and tighten to specs. (i.e. as per FSM to be safe - you'll need a spring scale). If you still have play even with the spindle nut snugged, the bearings are worn and you'll have to replace them. This is my situation - it's on the list before the car comes out in the spring.

 

Correction: if you still have play with the nut snugged, you didn't spin it after tightening, then re-tighten and repeat. I'm telling you, it works like a charm. Worn bearings rumble, loose bearings are simply loose... it's a taper bearing.

Oh, and the spring scale thing is a cruel joke. I don't know a shop in all of Virginia that has one of those.

 

thanks everyone fr your insight. i will go and try that this weekend. is there any advice on how to repack the bearing while they are still part of the hub? any way to clear out the old grease with out hurting the bearings? thanks again

 

when u pack the new grease in, it basically pushes the old grease out. that is when u know u packed it with grease properly. The grease needs to get into the bearing cage. You could use some solvent and a brush and brush it if you want. But i like the old grease because its an indicator the new grease is taking its place

You could jsut retighten the nut on the older bearings, but just know it's old and will need replacing. Of course like some people mentioned, run it till it goes bad

 

Alexdimen - you absolutely sure about that? I was afraid to overtighten my bearings, so I may have not snugged them up enough. I have a very small amount of play, but no rumbling or noise whatsoever. Being taper bearings, and the fact that all ***** should wear evenly, it makes sense.

Oh, to the other poster...the only part of the assembly that doesn't come out readily is the outer race of each bearing. The rest comes out. I like to use rags/paper towels to take most of the grease away, then get them spotless with brake cleaner or varsol, then air dry thoroughly. Then I regrease with plenty of clean grease, making sure they're saturated with grease between *****, cage and put a whack on the whole assembly. They sell inexpensive bearing packers you can probably find.

 

I think you've misunderstood me. I'm not suggesting that you over tighten the nut.

What I'm saying is that you tighten the nut, then spin the hub by hand. Every time you spin the hub, the rollers will seat a little better in the tapered race and you will then be able to take up a little more slack by tightening the nut again. Repeating this until the nut no longer moves after spinning the hub has worked very well for me.

I gauge the torque I put on it by feel and i definitely don't wrench down on it. It usually takes me 5+ spins of the wheel to get the bearing nice and snug. This is with the nut budging about 1/50th of a rotation each time with light/moderate force on it. Probably between 14 and 18 lb*ft.

They aren't ball bearings. They are roller bearings in a tapered race. They can loosen up from natural and often even (if there is no noise) wear, from the nut backing off slightly over time, or a combination of the two.

If you guys want to do it the hard way, that's fine with me. I'm just trying to save you some effort. Just keep in mind that brand new wheel bearings can loosen up just as easily as old ones if not tightened and seated properly and then you're back to where you started.

This is one of those things where the mazda manual procedure is a load of ****, but hey nobody ever listens to me...

 

It's super easy to disassemble, I'd just take the bearings out. Find instructions or just pick up a Haynes manual if you're not sure how. Dunno how else you could get grease into the sealed inner bearings.

Oh, and I couldn't find a usable pull scale anywhere. Went to a fishing store, but its weight limit was way to high to measure a couple pounds. So I had to guestimate. I'm gonna try alexdimen's procedure next time, since the mechanics are way too simple for me to think that there are many differing opinions that need considering before I risk smoke and fire and explosions and rivers of blood.

 

use brake cleaner for a fast clean ... or you can use some warm water and simple green then dry... never repack with any fluids on them


you should not repack over old grease... first you can't tell the condition of the bearing and second there is a chance that you will leave contaminates in the bearing which is pointless

 

glad to see more info guys. im going to be doing this on sunday if the weather is good. expect to see some pics.

 

Hi.
I changed my front bearings after 200k miles because the races were worn out. The left bearing began to make an inconspicuous sound which came and went as it liked but over time got louder. I thought that I maybe used too little grease and repacked them without any change. The bearing and races still look like new after about 30k miles but in the meantime its way louder than the original bearings. So did I just had bad luck or did I do something wrong?

Harry

races out

 

One of my replaced bearings failed too. It was one of the outer ones. However, mine was visibly damaged. I changed the outer race/bearing, repacked the inner and it's been fine.

Sometimes you get crappy components. I no longer trust NTN bearings after that. I'd much rather have a Koyo or federal mogul bearing.

Try this: jack the car up and spin the wheel with one hand while holding the coil spring with the other hand. If you feel vibration/rumbing with your hand on the spring, then something is wrong with the bearings or races.