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Post by coondog on Jan 7, 2016 13:58:13 GMT -5
Hey, so I am trying to figure out why I am about to install the third set of bearings in the last 5k miles. I feel like this bearing setup is a poor design, and these bearings have a hard time staying lubricated. I add a lot of grease when I do the bearings, and use a digital torque wrench to set the axle nut, and its not a wobbly tire, but the bearings are now grinding again, and I am sick of replacing them. One time when I did the bearings, I put new everything on the passenger side, including the whole spindle. I can see its in good shape, and the bearings sit nice inside of it. I also had a machined spacer to go between my bearings because the one I found inside was just badly chewed up. I measured the space between the two bearings before machining a spacer, and feel like thats not the problem. I wonder if I am just not putting enough grease in there or something, because I feel like I read a thread on here about someone using like half a tub just packed all in there before putting the seals and axle in.
Any suggestions appreciated before I take it all apart again on saturday...Thanks, Connor.
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Post by certimafied on Jan 7, 2016 19:26:12 GMT -5
Initially I would say not enough grease or wrong torque, but that has been covered.
After that off the top I would ask if you have used the same brand of bearing each time? Maybe a bad manufacturer?
Is the suspension ok?
What about the seals? How is the grease getting out?
Theres my two cent...
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Post by madmatt on Jan 7, 2016 19:32:39 GMT -5
I also had a machined spacer to go between my bearings because the one I found inside was just badly chewed up. I measured the space between the two bearings before machining a spacer, and feel like thats not the problem. Connor, From your other posts, you seem like a competent dude... but how did you measure your chewed up spacers? Let's think that a thou out or so would pretty quickly destroy a set of bearings. I once had a parts car that had NO SPACER, and that's why it was junked, because it was on it's 3rd set of bearings... and the owner couldn't figure out what was wrong. Anyway, imagine a thou or so out undersized, and how quick that would kill the ball bearing type we have if loaded to "correct" torque... I've had the same set of bearing in the front of the rally car since 2004, they were cheap aftermarket no idea on brand... and they take a friggin beatin'.
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Post by Deleted on Jan 8, 2016 14:20:21 GMT -5
The main cause of bearing failure is over-packing with grease, and is a common problem for DIY bearing replacement on these older Subies. More isn't necessarily better. From the sounds of it, it's more likely that you are putting in too much grease rather than not enough.
The simple explanation is that bearing grease is essentially a wax base impregnated with lubricant. When the grease heats up the lubricant flows out of the grease to lube the bearings. If you have the bearings packed too fully, then the wax heats up and gets pushed and pressurized into the bearing surfaces and causes premature bearing failure because the wax doesn't have the correct properties to be the lubricant over extended periods of time (not to mention hydraulic friction losses). Once this process starts, it will tend to self-perpetuate because the bearing will just get hotter and hotter due to the wax, which will cause more wax to get smooshed into the bearing surfaces until the bearing fails. The bearings really only need and prefer a relatively small amount of lubricant.
That's why I just use sealed bearings now. It's way easier and takes out the guess work. They already have the correct amount and type of grease for which they were designed. People that remove the seals and clean and repack their new sealed bearings are just fooling themselves if they think they are getting a net benefit. In rare cases, more extreme-use scenarios, you might get a net benefit, but if you are doing that, then you probably could/should have ordered better bearings in the first place.
You can get these bearings from any bearing house for (typically) much less money then a auto parts supplier, and they will usually have a larger selection. I think I paid $12 ea. for mine last time. You just need the bearing number and they will probably have that bearing for all kinds of applications. There will be a main part number followed by an alpha-numeric code (usually just one or two digits) that indicate the application. I will say that you probably don't want a version of the bearing designed for an electric motor because they are typically manufactured to tighter tolerances than an automotive application, and you might end up with thermal expansion issues in the bearing.
Also, make sure the conical spacer for your hub is in good condition.
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Post by coondog on Jan 10, 2016 0:18:23 GMT -5
I went to the dealer this week and ordered the spacer between the two bearings, because I wondered if the one I had made was too thick and preloading that bearing. I ended up finding sealed bearings so I am gonna run them. I went to Subaru a while ago and picked up a few of those cones that go behind the wheel nut.
I am thinking the thing that killed my bearings was the spacer between them being too thick. I had it machined and I figured I.measured everything good, but there was not one in there when I got the car to compare it to.
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Post by madmatt on Jan 10, 2016 6:11:08 GMT -5
Too thick wouldn't let the bearings seat properly against the shoulders... Might cause an issue for sure.
Too thin would allow the bearings to seat, then when you torqued it down, your torque reading would come from side loading the bearings together, rather then squeezing the spacer between the inner races... Meaning EVERY mile you drive the bearing would be sideloaded... pending doom.
It will be neat to compare your spacer to the stock one. Really, I'll bet a thou or 2 of an inch out would be enough to preload too much...
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Post by coondog on Jan 13, 2016 11:34:49 GMT -5
I get the hint gentlemen, I probably f'ed up the clearance between the bearings. This is how I came up with my measurement to make a spacer. I pressed one bearing into my new hub, measured the distance from that bearing to the edge of the shoulder that the spacer sits in, and used that thickness. Then I put the new spacer in, pressed in the second bearing and check out how the spacer sat in there. It was what I consider a good fit. There was a snug fit, but still able to barely slide the spacer back and forth to be able to line it up to slide the axle through. I think my measurement was somewhere around 12mm, but to confirm that, I will post up pictures of it mic'ed next to a subaru spacer mic'ed to compare how off I was. The part was supposed to arrive monday, but haven't seen it yet.
My original thought is that it would be no big deal, but I am finding out now that it is. My step-measurement idea was not so hot as I am finding out.
This is a humbling experience to admit my mistake, to say the least. Its funny, because I do some intense transmission work for a living, and yet I have this little justy, often referred to as cute, whip my ass. The guys at the auto parts store clown on me, and Im ok with that today haha
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Post by gearheadeh on Jan 13, 2016 12:55:52 GMT -5
It takes a REAL man to admit when he is wrong. Not that this is that big of an error ! I think that I would have done the same thing faced with not knowing or having the correct part. The bigger thing here is that you had the guts to tell us what was up, I for one really appreciate it.
There are so many build threads and calls for help littering the net that are not completed and everyone is left in the dark as to what to do--- or (Not to do!)
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Post by madmatt on Jan 13, 2016 15:19:56 GMT -5
I get the hint gentlemen, I probably f'ed up the clearance between the bearings. This is how I came up with my measurement to make a spacer. I pressed one bearing into my new hub, measured the distance from that bearing to the edge of the shoulder that the spacer sits in, and used that thickness. Then I put the new spacer in, pressed in the second bearing and check out how the spacer sat in there. It was what I consider a good fit. There was a snug fit, but still able to barely slide the spacer back and forth to be able to line it up to slide the axle through. I think my measurement was somewhere around 12mm, but to confirm that, I will post up pictures of it mic'ed next to a subaru spacer mic'ed to compare how off I was. The part was supposed to arrive monday, but haven't seen it yet. My original thought is that it would be no big deal, but I am finding out now that it is. My step-measurement idea was not so hot as I am finding out. This is a humbling experience to admit my mistake, to say the least. Its funny, because I do some intense transmission work for a living, and yet I have this little justy, often referred to as cute, whip my ass. The guys at the auto parts store clown on me, and Im ok with that today haha Connor... Seems completely logical to me too! How I would have done it... Interesting to see what the new spacer is from Suby... probably 12 mm, and then mud on all our faces And you back to wondering why you're burning up bearings. FWIW... I have a Volvo S40 DD, the fun turbo one... it burns through front wheel bearings every 60K Km's... which for me is every friggin' 2 years. They are $350 dealer... I can get them for $90 aftermarket, and then they last 1.75 years... I'm on the 5th change over.
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Post by gearheadeh on Jan 13, 2016 17:11:42 GMT -5
FWIW... I have a Volvo S40 DD, the fun turbo one... it burns through front wheel bearings every 60K Km's... which for me is every friggin' 2 years. They are $350 dealer... I can get them for $90 aftermarket, and then they last 1.75 years... I'm on the 5th change over. Ouch!
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Post by coondog on Jan 23, 2016 15:03:02 GMT -5
Hey guys, heres the deal...
I had been delaying the inevitable for a few weeks now, until I found out this week we had a big snow storm coming. I originally bought the justy for this snowy weather, so I went into overdrive to get it done. I put everything on hold at work on tuesday, so I could get my car done. I pulled it apart, and measured the spacers side by side.
The one I had made by a machine shop measured 11.47mm, and didnt seem to be true. Like it was the same thickness, but it wasnt flat(if you know what I mean).
The one I ordered from subaru was 11.5mm, and truely flat.
I threw in some new sealed bearings, seals, and subaru spacer. It is now driving fine, but we will see in about 1k miles.
It was a humbling experience to go through this over and over, but hopefully it is fixed now. I am sharing this information to hopefully give someone else some insight if they are having the same issure...
Madmatt, I have a guy at my shop who worked at volvo for like 19yrs, from 1990 to 2008, and i know he will have a lot of experience that might help. I'll tell himm about your volvo and see what he does to get longevity out of those bearings. What yr s40?
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Post by madmatt on Jan 25, 2016 20:19:10 GMT -5
Thanks... I think there is nothing to be done other then respect some monkey spec-d to light of a bearing for 3400lbs of moving metal... without having numbers in hand the stock rollers are probably less then 5-6mm... It's a huge bearing, but no space for rollers, so the roller speed goes way up... for every mile my S40 travels, its rollers probably revolve 2-3x what my '84 240's conical bearings did... but you don't need a feeler gauge to put them in, so that saves time, and hence $$$ until the fawkers blow... I'd rather feeler gauge then in, then set pre-loaded bearings, but hey we would be paying for labour at the service end... oh yeah wait, put money in the pocket of the middle class... ? damn...why would I want to pay me? But it's a '05, Turbo AWD.... the stupid big brakes and tiny wheel bearings.
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Post by coondog on Jan 27, 2016 16:49:13 GMT -5
Heres a funny one to keep this thread exciting...
So, I got my justy done just in time for the big east coast snow storm, and I was pumped to 4wd this little car.
It did well, surprisingly well.
As soon as the snow melted, I was out driving along, and when I went to shift gears, I heard motor blowing noises, and the engine shut off while I was going like 40mph. I cruised into some weird thai resturaunt parkinglot, and got out and looked under the car.
Saw nothing leaking, so I popped the hood. The timing cover was temporarily off, and I saw the belt flapping in the wind.
Looks like the bearings came apart for the timing belt tensioner, and it shot the pulley right off the bolt. The races are still on the bolt, which is why I believes the bearings failed.
Now its dead again...
I read that the justy is not an interference motor, so we are hoping for the best.
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Post by madmatt on Jan 27, 2016 17:15:38 GMT -5
lol...
long story, but I lost a cam pulley at speed and high rpm...
I've decked the head 1.5 mm and still had no clearance issues.
so, no damage.
put it back together and drive on!
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Post by coondog on Feb 1, 2016 15:32:36 GMT -5
Ya I got the timing belt and new tensioner kit in and everything has been good so far. When I was setting the timing marks, it seemed like I just couldn't get the belt tight enough to line up DEAD ON. They are pretty close, but not like how I prefer it. ..Now it feels like it has low vacuum at idle, so I guess it might need to be re tightened once I get some more miles on it. The RPMs fluctuate a little bit at idle, and it doesn't idle quite as smooth as it did before. The tensioner has a little more room to go, but I couldnt get it any tighter because there was no where to get a pry bar in and push the tensioner in more. Its not a big deal, but I try to get it running as close to 74hp as possible ha.
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