TheSamba.com :: View topic - oops, i'm out of my depth in the wheel bearings

Sat Oct 24, 2009 7:00 am

Hi,
I've just bought a '79 bus in northern Greece, driven it down home to Crete and now i am in the process of getting it road worthy. I have a problem with the brake pedal pulsating, and in the process of chasing that down I noticed that the front wheel bearings have a lot of play.

I jacked up the front, took off the left dust cover, loosened the clamp on the nut, and instead of tightening up the bearing i got curious, as I haven't visited this part of a bus before.

I took off the nut and the thrust washer, and pulled out the outer roller bearing (all new to me). Some of the grease seemed a bit crusty so i scooped a fair bit of it out.

Now I'm not sure what to do to put it back together. I have no reason to believe that the bearings need replacing, so I am wondering if, at this stage, I can somehow clean out remainder of the grease and repack it and adjust. If so how? Or to do this do i need to remove the wheel, rotor and take the hub off?

Cheers,
Nick

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Sat Oct 24, 2009 7:11 am

Use a solvent to clean the old grease out of the bearing and repack it with fresh grease. To do a complete job you will need to remove the brakes and the hub in order to get to the inner bearing and do the same clean and repack it also. You'll also want to replace the grease seal on the back of the hub.

Sat Oct 24, 2009 8:37 am

ok thanks, and I'm guessing that I should pack the space behind where the outer bearing goes with grease too?

Nick

Sat Oct 24, 2009 8:52 am

Don't fill the hub with grease, a good 1/4" thick smear on each side of each bearing after they are packed and installed is all you need. Extra grease does nothing and just makes the next job messier.

Sat Oct 24, 2009 9:53 am

When you repack wheel bearings it's a good idea to replace the grease seal too.

Put everything back together, tighten the nut gently and give the wheel a spin. This squeezes the grease out of the bearing. Now gently tighten it again.

Sat Oct 24, 2009 11:05 am

Read up on hand packing bearings. You want to do more than just smear new grease on the outside of the bearing before reinstalling it. Not hard to do and really easy to demonstrate, but kind of hard to put into words. Maybe someone else will take a shot at explaining now to do it.

Your brake pedal is probably pulsating because either the rotors or drums are out of round and will need to be turned.

Sat Oct 24, 2009 1:17 pm

To get it road worthy like you want, it would be best to clean and grease both the inner and outer bearings. You will need new grease seals for the inner bearings. This job is just normal routine maintenance. Your loose wheels and cruddy grease suggest that it might be long overdo. Unbolt the caliper and swing it off of the disc.
It would sure be nice if someone did a little video of packing a bearing. Wildthing? It obviously would be a two man job to do the video :lol: .

Clean the bearing like was mentioned and make sure it is dry. Carefully inspect the bearing and the outer race for any pits, obvious wear or bluing. If you replace a bearing you also have to replace the outer race.
Put a gob of wheel bearing grease in the palm of your hand. Cup your hand real tight like if you were getting a drink out of a stream. With the other hand holding the bearing push the edge of the bearing down firmly into the grease. The goal is to force grease into one end of the gap between each bearing roller until it squishes out the other end. Keep working around the edge until it's filled. You will need to frequently add too and regather the gob of grease in your palm. Flip the bearing over and go around the other side. Do it until you are convinced that every void in the bearing is filled. It's messy but it's fun if you pretend you are a little kid making a mess.
Big thing is cleanliness. Fully clean all the old grease out of the hub.
Tighten up the bearing like Rusty say's. Do it a couple times and rotate it to make sure everything is great. For the final tightening, gently snugly tighten the nut and then back it off slightly. Push and pull on the outer edge of the tire. Adjust the nut until you can just barely feel a minute (very very small) amount of play or looseness. Just enough play so that you know that is is not without any play. Tighten the clamp. Smear some grease in the cap and put it on.

Sat Oct 24, 2009 1:45 pm

Nick-

You really need to get a service manual first thing. That would probably be the biggest step in getting it road worthy.

Sat Oct 24, 2009 11:34 pm

Thanks very much for the descriptions - very much appreciated. I do have several manuals - bentley, muir, and a haynes one, and have read the wheel bearing sections in all several times.

I am still a bit confused about terminology and the parts involved. From what I understand there are two bearings, an inner and an outer. Each bearing has an inner race and an outer race. The Bentley manual says that the outer races must be removed and installed with a hydraulic press. The Muir manual says that the "inboard inner race" is what needs pressing. If anyone could clarify this for me I'd be really happy.

Another thing about the bearing races I'm still not clear of. For a "routine maintenance" repack of the wheel bearings, do you need to remove the outer races (ie take the hub into a shop), or do you only do that if you are replacing the bearings?

Thanks,
Nick

Sun Oct 25, 2009 5:55 am

You don't have to touch the races at all unless you're replacing the bearings. For a simple repack, as long as your bearings are in good shape, you don't have to worry a thing about the races. And you don't need a press to install either set of races. A simple bearing and race driver tool is all you need.

Mon Oct 26, 2009 5:10 am

VDubTech, thank you for the info. I will remove the brake caliper, rotor, and hub and do a proper clean and repack of the bearings rather than try and patch up from where I'm at now (assuming the bearings and races are ok on inspection). Bloody stormy weather in Crete right now, and now i have a perfect job for a rainy day.

Nick

Mon Oct 26, 2009 6:38 pm

Wildthings wrote: Read up on hand packing bearings. You want to do more than just smear new grease on the outside of the bearing before reinstalling it. Not hard to do and really easy to demonstrate, but kind of hard to put into words. Maybe someone else will take a shot at explaining now to do it.

Your brake pedal is probably pulsating because either the rotors or drums are out of round and will need to be turned.

Wash the bearing with Varsol or kerosene and blow it dry with an air hose. DO NOT spin the bearing with air.

Put a gob of grease the size of a golf ball in the palm of one hand. Hold the bearing in the other hand with your fingers thru the middle. Squash the bearing into the grease over and over until the grease squishes right thru between the rollers and comes out the top.

Turn the bearing in your hand and squish the grease thru the next part. Keep turning and squishing until the bearing is packed full of grease.

Smear the excess grease around so the outside is coated too. Now the bearing is ready to install.

When replacing bearings, it is not necessary to remove the wheel from the hub, in fact it is easier if you leave the wheel on.

With the wheel jacked up, remove the hub cover and unscrew the big nut but not all the way off, leave it on part way. Give the wheel a wiggle and the bearing will pop out. Now you can take off the nut and the bearing without dropping the bearing in the dirt.

To remove the inner bearing lay the wheel flat and pop it out with a hammer handle. Stick the handle down against the bearing and tap a few times, the bearing and grease seal will fall out. Make sure there is enough room under the wheel for it to fall out, put blocks under the tire if necessary.

Wipe off the outer races and inspect them and the bearings. They should be smooth and slightly dull. If they are pitted, scored or rough looking it is time for new bearings.

Tue Oct 27, 2009 8:03 am

See if this works...

Peace!

Thu Oct 29, 2009 7:11 am

thanks. I have a couple of other questions:

I want to remove and repack the inner bearing. Should the inner grease seal (pictured below) just pop out, or this there a method to removing it so that it can be reused once i've repacked the bearing - mine seems tightly fixed in place:

Another question:
I've had my bus jacked up for a week with the wheels off and the rotors are getting a layer of rust on them.. is this a problem or will it just rub off as soon as they are used again?

thanks again for all the advice.

Nick

Thu Oct 29, 2009 7:20 am

The grease seal will pop out with a large screwdriver or a prybar, and as has already been said at least twice in this thread already, should be replaced when you reassemble. This is stuff you should have before you start the job. this is like an hour's worth of work, why are you still working on this? What's the holdup?

Thu Oct 29, 2009 7:40 am

yeah, i piss around a lot. especially on the first time but also this week we've had storms and been without power for a couple of days, and the brake caliper bolts were seized... add to that trying to find parts in a country where no-one mechanically minded speaks english... yep i know, i can hear the violins playing now ;P