Rear shock linkage maintenance

[LAF]

Well at 24,000 miles you can plainly see the needles are not spinning in my top link, or the other two as all three look the same. In the top right you can see a piece of this material breaking away, I stuck it down with grease. Not trying to fuss over this but there is no way in my mind could I see this thing function without the material in between the needles. If it was not there the needles would just drop to the bottom, collar or not.

I am just trying to learn a bit and I do agree it is kind of a messed up arrangement and a PITA to do.

I guess my point is not to even try to pick at that stuff as that is what spaces the needles and is worn with the collar as the pic plainly shows.

The needles are not spinning as a traditional bearing or in any kind if race, it is the material that is being used to wear on and the needles are really just a spacer or support for this material.

 

[BobbyBlue]

I just name all the squeaks....they're like the weight...disappear over 7 mph....keeps deer away too.....cheaper than cat food.

 

[yamafitter]

... These in no shape, way, or form, at least to me, are a bearing. These are bushings...

Negative. The parts in the relay arm that provide for movement are definitely bearings. I got the following comparison off the internet so it must be true...

Generally speaking, a bushing is a soft metal or plastic one piece part designed to keep a harder pin, shaft, or what have you, aligned while allowing free movement. The bushing wears out and is replaced as needed. A bearing is usually a three piece part consisting of an inner race, an outer race, and balls or rollers in between. Properly applied, bearings provide better alignment, less friction, and last longer.

In the case of the bearings in the relay arm there is an outer race, the needle bearings, the soft plastic that acts as a cage for the needle bearings and the collar provides the inner race. I have seen this type of construction before where the plastic material is impregnated with a type of lubricant for the needle bearings and according to the manufacturer do not require additional grease. Those of us that dirt bike know this to be BS once dirt gets into the bearing and grinds everything up.

With these particular bearings if the plastic cage for the needle bearings are damaged or removed the needles are no longer spaced evenly and will no longer support the collar properly. If you lose half the needles like I did the problem is amplified.

 

[LAF]

... These in no shape, way, or form, at least to me, are a bearing. These are bushings...

Negative. The parts in the relay arm that provide for movement are definitely bearings. I got the following comparison off the internet so it must be true...

Generally speaking, a bushing is a soft metal or plastic one piece part designed to keep a harder pin, shaft, or what have you, aligned while allowing free movement. The bushing wears out and is replaced as needed. A bearing is usually a three piece part consisting of an inner race, an outer race, and balls or rollers in between. Properly applied, bearings provide better alignment, less friction, and last longer.

In the case of the bearings in the relay arm there is an outer race, the needle bearings, the soft plastic that acts as a cage for the needle bearings and the collar provides the inner race. I have seen this type of construction before where the plastic material is impregnated with a type of lubricant for the needle bearings and according to the manufacturer do not require additional grease. Those of us that dirt bike know this to be BS once dirt gets into the bearing and grinds everything up.

With these particular bearings if the plastic cage for the needle bearings are damaged or removed the needles are no longer spaced evenly and will no longer support the collar properly. If you lose half the needles like I did the problem is amplified.

Well I guess it is a bearing then. Still I think the next time I go in I just will buy 3 new and be done with it. They cant cost that much, right?

 

[RossKean]

Just looked up the price for all the bearings (6 total) and oil seals (8). Comes out to $110.16 (Yamaha Sportscenter). Doesn't include bolts, nuts, washers, collars etc. or shipping. This is for a Gen II. I think I will check what's there before I go and replace all of them.

 

[Auburn]

Just looked up the price for all the bearings (6 total) and oil seals (8). Comes out to $110.16 (Yamaha Sportscenter). Doesn't include bolts, nuts, washers, collars etc. or shipping. This is for a Gen II. I think I will check what's there before I go and replace all of them.

all balls website, they are probably cheaper and usually are better grade.

 

[RossKean]

Just looked up the price for all the bearings (6 total) and oil seals (8). Comes out to $110.16 (Yamaha Sportscenter). Doesn't include bolts, nuts, washers, collars etc. or shipping. This is for a Gen II. I think I will check what's there before I go and replace all of them.

all balls website, they are probably cheaper and usually are better grade.

Can't find a model-specific listing.

 

[HotRodZilla]

The plastic "film" between the rollers is NOT lubricant that just hardened up. Yammafitter is correct that the plastic is there in purpose and is an integral part of the bearing's function. Picking that stuff out basically ruins the bearing.

Grease them all you want, but don't pick the plastic out of them.

 

[LAF]

The plastic "film" between the rollers is NOT lubricant that just hardened up. Yammafitter is correct that the plastic is there in purpose and is an integral part of the bearing's function. Picking that stuff out basically ruins the bearing.
Grease them all you want, but don't pick the plastic out of them.

What you said.

 

[LAF]

Just looked up the price for all the bearings (6 total) and oil seals (8). Comes out to $110.16 (Yamaha Sportscenter). Doesn't include bolts, nuts, washers, collars etc. or shipping. This is for a Gen II. I think I will check what's there before I go and replace all of them.

Next time I will see mine is around 50,000 so I will just replace them for 110.16. Thanks for pricing them out.

 

[Fred W]

I disagree based on first hand experience. The plastic stuff serves no purpose once the inner collar is inserted into the bearing. The tolerance between the outer bearing race and the inner collar is precisely the width of the needle rollers, and the circumference is just barely enough to fit all of the rollers in. The plastic doesn't space the needles out at all, just retains them when the collar isn't there. There are no spaces to speak of between each of the needles so they will not collect at the bottom of the bearing.

I removed all of my plastic stuff and the needles the first time I serviced my suspension, then stuck some fresh grease into the empty outer bearing race. The needles can then easily be stuck into the fresh grease and will stay put until the inner collar is inserted, which will then keep them perfectly well.

And the whole assembly most definitely is intended to act as a bearing where the needles roll when the inner collar rotates inside the arm. LAF does make a good point that, with the plastic stuff in there, the needle rollers will be less free to roll, and that may explain some of the scuffing wear marks we usually see on these collars when disassembled.

The bearings that I serviced this way 2 years ago look just as good last month when I serviced them again as they as they did 2 years ago. I would not be afraid to remove that plastic stuff. Just be ready to catch the needles when they come out and stick them back in with grease.

YMMV

edit - As for "just replacing them", they need to be pressed in. Soi unless you have a press and can do this at home your stuck shelling out money and shlepping them to a machine shop to get those bearings replaced. It's a darn bit easier to just make sure that they are well lubricated at each service as they will probably last the life of the bike then.

 

[Auburn]

I agree the plastic is there just to hold the needles in place. I believe you see wear localized to a small area is the linkage only moves so far and repeatedly on the same spot. If the bearing is greased properly and doesn't dry out then it just polishes the area. If it dries out then we see bushings look like what skooter's does.

 

[Fred W]

You are probably right about the wear marks. That was my initial thought too. With the weight of the bike on those needle rollers, they're going to roll, not slide.

 

[LAF]

I disagree based on first hand experience. The plastic stuff serves no purpose once the inner collar is inserted into the bearing. The tolerance between the outer bearing race and the inner collar is precisely the width of the needle rollers, and the circumference is just barely enough to fit all of the rollers in. The plastic doesn't space the needles out at all, just retains them when the collar isn't there. There are no spaces to speak of between each of the needles so they will not collect at the bottom of the bearing.
I removed all of my plastic stuff and the needles the first time I serviced my suspension, then stuck some fresh grease into the empty outer bearing race. The needles can then easily be stuck into the fresh grease and will stay put until the inner collar is inserted, which will then keep them perfectly well.

And the whole assembly most definitely is intended to act as a bearing where the needles roll when the inner collar rotates inside the arm. LAF does make a good point that, with the plastic stuff in there, the needle rollers will be less free to roll, and that may explain some of the scuffing wear marks we usually see on these collars when disassembled.

The bearings that I serviced this way 2 years ago look just as good last month when I serviced them again as they as they did 2 years ago. I would not be afraid to remove that plastic stuff. Just be ready to catch the needles when they come out and stick them back in with grease.

YMMV

edit - As for "just replacing them", they need to be pressed in. Soi unless you have a press and can do this at home your stuck shelling out money and shlepping them to a machine shop to get those bearings replaced. It's a darn bit easier to just make sure that they are well lubricated at each service as they will probably last the life of the bike then.

Fred W I do follow your logic and believe you when you say you did this service in the way you did. The only question I have is did you look at my picture? Can you see that in fact the needles are not turning in there? The plastic is worn but the needles are not loose or spinning. This is why I am asking. I would say the collar is moving or spinning against the plastic and needles?

 

[Fred W]

While it looks like the plastic is tight on the needles, I'd bet that they are actually free to spin inside the plastic retainer. There is probably some oily lubricant in there, either oil or broken down grease. At least there was on mine. If you put the collar back in and rotate it with a load on the bearing the rollers should turn.

 

[Panman]

I agree the plastic is there just to hold the needles in place. I believe you see wear localized to a small area is the linkage only moves so far and repeatedly on the same spot. If the bearing is greased properly and doesn't dry out the it just polishes the area. If it dries out then we see bushings look like what skooter's does.

The wear you see is called brinelling, I would worry about it if these bearings were a high speed bearing. I'm not so sure that this set up is the best for what it does but it works.I really don't think it matters if the plastic retainers are in or out long as you clean them out and stuff new grease in every couple of years. I might lean towards plastic out as then you can stuff more grease into the bearing.

 

[TomInPA]

I got first-hand advise from "Cisco" who is the respected mechanic at Roseville Yamaha, the plastic cage can be removed, and the bearings fitted into a greased race. It's good enough for me not to replace the ones with the disintegrated plastic cage. Be sure to use a magnetic tray if you disassemble. These things like to run away. The compressed air technique is a sure winner to have to replace all.

 

[yamafitter]

edit - My intial post was based on my observation of the bearings supporting the dogbones and was misleading.

See my following post for my correction.

 

[Fred W]

I cannot agree that it is OK to remove the plastic cage and replace the cage with grease. When you remove the plastic cage there is now nothing other than the grease to stop the needles from migrating and you could possibly end up with a situation where the collar is unevenly supported by the needle bearings. Fred obviously got away with it and the needles did not migrate enough to cause a problem but it does not mean it cannot happen.I just believe that removing the plastic cage is a poor practice that should be avoided.

Billy, where are those needles going to migrate to? They already go all the way around the bearing and there is no extra room or space between them for them to migrate off to.

The bearings at both ends of the dogbones are different. They have metal retainers and the needles do not fill the entire circumference space, so they do have spaces between them. We're just talking about the two bearings at the front frame tab and rear shock ends of the relay arm. Those are the ones with the plastic stuff.

 

[TomInPA]

My experience with it is the needles fill the race, and don't have gaps. There is no place for them to move around, and the collar is well supported by the bearings without the cage. IMO, it's not possible to clean and lube the needle bearings with the cage in place, about all you can do is smear some grease around the cage and hope it penetrates to the bearing and race. The retaining cage seems to deteriorate to the point it might be what migrates and ends up blocking the smooth movement of the bearing needles.