Tag Archives: SKF bearing

Front wheel bearings and other horror stories

Let me tell you a story that I think you will find hard to believe. I find it hard to believe. In fact, if I hadn’t seen it with my own eyes, I wouldn’t believe it. I wouldn’t want to believe it anyway. It’s basically a story about low IQ, and motorcycle ownership with a bit thrown in at the end on how to replace front wheel bearings on your AG200!

A few years ago before the end of the naughties, I was helping out at a small, country Yamaha dealership. The owner was between mechanics and I thought I would help out with the spanners for a few months while he managed to track down another victim, errr employee! For the six months or so I was there, I saw mechanical horrors that no technical person should ever have to see. I still have nightmares to this day…

Things that make you incredulous that we are the dominant species on this planet! Things that make you shudder and doubt that humanity even has the right to go on! There will always be one encounter though, one special “Bobby Dazzler” example of how far someone can push the boundaries of neglect and stand out from the crowd, and man is it a special crowd! It’s one of those things that you wont forget until your final days. Unfortunately this experience for me involved an AG200.

The experience in question started as I was labouring away, minding my own business in the workshop when a guy shows up in his 4WD with trailer in tow. Alarm bells went off before I even got a look at the bike because the poor thing was chucked in the back of the trailer with no restraints. Yep, just tossed in on its side! My idiot detector went off instantly and thought he can unload it himself if he is too pathetic to even load a bike up properly (I never was a good long term employee!). A few minutes later he pushes this poor thing into the shop,  leaves his name, address etc. and off he went on his merry way mumbling something about “they don’t make ’em like they used too.”

After he drove off I thought I’d have a look at the treasure he left us to repair. I wish I had taken photographs, I really do wish I did. The guy was complaining about front end problems and boy did he have that! The front wheel bearings had collapsed completely to the point where the ball bearings were gone…completely! Now you can forgive someone for  a bit of play in their front end but can you imagine the play this thing had? let me tell you how much movement was in the front wheel; it was hitting the forks!

But wait, it doesn’t stop there dear reader. When the bearings collapse in the front wheel of your motorcycle, you’re going to notice it right? You’re going to think; “Oh, better get that looked at, this thing is getting a bit wonky to ride.” But noooo, not this clown! I don’t know how long he rode it like that but it was long enough for the tyre to wear through the fork legs. Yep, through the fork legs! The Aluminium just under the oil and dust seal was removed right back to the slider on both forks, where it had rubbed the chrome off them as well.

Believe me? I wouldn’t. Unless I had seen it myself with my own eyes, I would find it hard to swallow this story  if someone had just told me. I should of taken photos but at the time I think my brain was in some sort of paralysis because of what I was actually seeing. I actually took it for a ride and concluded that it could only be worse if the front wheel had actually fallen off. Diabolical was the only word that I think comes close to how that bike rode with the front end like that.

The whole front end was scrap in my books but the owner insisted that he didn’t need brakes (the hub was all mashed up), or the pesky oil in the forks, slap some new bearings in it and he was good to go! The axle, spacers and inner bearing races were a big, corroded blob of destruction and he screamed at the cost of new, genuine replacements, which I thought were a waste on this moron’s bike anyway. Surprisingly, some new bearings actually fitted and stayed put in the hub, we nicked the other bits off a wrecker and off he went, still bitching at the cost of it all!

I always wanted to “out” this guy as the mechanical terrorist that he is, but what would it achieve? He is still destroying farm equipment to this day and will until he’s in a grave. I always thought, and was taught, that farming was a business. So why don’t farmers treat their equipment as part of their bottom line? It has always baffled me but the answer is probably that a lot of farmers, particularly in the past, never had much concept of  business anyway. Time has caught up with a lot of them. But I digress…

What’s with the story AGman? I thought this post was about front wheel bearings? Well it is but there’s not a lot involved with front wheel bearing replacement so I thought I’d put that entertaining little ditty in there so you will know how to avoid rubbing holes in your fork legs!

Off you go to the Front wheel removal section of my fork repair tutorial. This will give you an idea on how to get the front wheel off and what you have to do to achieve it. Once you have your wheel off and your stolen milk crate ready, place the wheel on it with the brake side facing down. This bearing is easier to knock out because it doesn’t have to pass as far in a press fit as the non-brake, seal side.

Get yourself a long drift or punch and slide it down the centre of the bearing until it reaches the opposite bearing’s inner race. You need a punch in pretty good condition with a good edge so it will hang up on the bearing. A few good whacks with a hammer and it should come out fine along with the centre spacer. Turn your wheel over and you will have much easier access to the opposite bearing which is a bit harder to move because, as mentioned, it has to pass through about double the material before it will drop out of the hub. You can remove the seal before you knock the bearing out but it doesn’t matter, it will come out with the bearing either way.

This is the rough method of removing the bearings. You can get special tools that expand in the inner race of the bearing and then with a slide hammer, you can remove it. Not everyone has easy access to these tools and they can be expensive. I have heard of people using DynaBolts (concrete or sleeve  anchor bolts) to use in bearing removal which is a good idea but may still need a slide hammer if you can’t bash the bolt from the opposite side, which you should be able to do. I will do some experimenting and check it out in an up coming post.

P1020583Back to the job…get yourself a couple of rubber sealed, 6301 bearings. I like SKF and NSK but any of the good bearing brands will do. I also pop the covers off the bearings, flush out the “grease” and replace it with a quality, waterproof substitute. I don’t expect you to do that but if you’re doing big miles on your bike I would defiantly recommend it. While you are at the bearing shop, get yourself a 18x37x7mm seal, they are cheap (as are the 6301 bearings I might add) and you might as well replace it with the bearings.

Installation is pretty simple. Find yourself a useless SAE socketP1020577 (American readers are gnashing teeth!) that matches up to the outer race of the bearing but doesn’t hang up on the hub. You can use this to gently tap the bearings into their P1020580new home. Don’t forget the inner spacer! You should also be able to install the new seal nearly by hand, if you do use persuasion, be gentle. Have a look at the photo of the seal below at right. Make sure it’s not flush with the hub. There is a plastic collar that fits on the axle spacer that slightly overlaps the hub a few mm. This helps to keep rubbish out of the seal and therefore the bearing. The link above showing the wheel removal procedure has some good pics if you need them. If this collar is damaged, it should be replaced for the long term health of everything discussed here.

There we have it, use grease on the seal lips, spacers and axle on P1020587reassembly. Make sure the speedo drive lines up correctly or there will be carnage. Another tip is to get someone to hold the front brake lever firmly to centre the hub while you are tightening the axle nut. We are done! Cheap, easy and no excuses for damaging those fork legs!

Cheers

AGman