XJ550 Seca Front Wheel Bearing Replacement

I’ve removed my old front wheel bearings and have two questions on installing new ones -

1. What is the proper sequence of installing the new bearings with the spacer? Left first, or right? The spacer seems to have the flange intact (can’t separate) and I’m not sure how to keep it aligned.

2. The replacement dust seal on the right side seems not as deep as the original. Is this a concern?

 

Ok, i got the new bearings in, but they are now stiff and hard to spin. The spacer is aligned but I can figure out why it is not freely spinning.

Should I loosen them out a bit?

 

how did you install bearings into rims?

put it on axle and spin tire. grease is thick .

 

Tapped them in with the old ones and seated them. Wheel does spin, but I was just surprised that I could not turn the inner races freely with my fingers compared to when I had the new bearings in my hand.

 

did you chill/freeze the bearings before the install?,
the spacer between the bearings puts lateral pressure on the races. then when you install wheel and torque the axle you will get more pressure.

 

It’s possible to drive them in too far, then the spacer will side load the bearings causing the binding you are feeling. I will usually check them as I go until the center races are just contacting the spacer.

 

I think it might help to think in terms of what really rotates when fully assembled. In the assembled stage, the inner race is stationary and the outer race is turning as the wheel turns.

 

That’s exactly what I did and have the extra stiffness as you describe. I guess it’s normal then?

 

yes I do think it is normal because the outer race is what turns when riding.

 

I firmly believe that if you can’t spin the bearing easily with a finger once installed it’s in too far and the spacer is pressing it sideways or side loaded. The balls should ride evenly in the groove or they will wear out prematurely.

 

here 's the rub if the bearings are installed to deep causing them to be sideloaded the bearings fail prematurly. choices: remove bearing and ruin in or run the bearings as installed, and check them with your maintance routine. when bad replace.
the only way most of us can install a bearing is by chilling them then tapping them in with old bearing as suggested in some manuals or using a large socket to tap them in.
so there is no way to tell because there is no spec listed as to how far in to go . I make the assumption that Yamaha did not over machine the back side of the hole to fit a feeler in there to see if you are in far enough or to tight. Also no manual I have read states to put a stright edge across the outer portion of bearing and measure clearance.
it is called real world applications.

he is good to go unless he pounded the hell out of them installing them .

 

how to do it

Front wheel bearing replacement

 

Using my bearing removal tool, i was able to tap out the left side a tad, so it is still flush enough for the tach drive. Movement is a bit better, so I’m going to stick with that and keep an eye on it.

Thanks folks!

 

Followed that, too. What’s interesting is that he says to tap in the new bearings until they go no further.

 

yup thats how its done

 

Even the service manual does not make any mention of how to install the bearing other than driving it in with a socket that matches the outside diameter. Obviously the bearing will wear quicker if side loaded but I have no idea how much quicker. I wouldn't consider it unsafe but IMHO the bearing should spin smoothly and as easily installed as it does right out of the package.

 

The thing about service manuals is that they are written assuming that a trained mechanic is using it (even the consumer service manuals are written that way). Bearings of this type are usually installed so the outer race is flush with the outer face of the bore, that way there is room behind the bearing for a bearing puller to grab the race for removal. In Fitz's writeup (from memory, I'm not where I can read it just now) he uses a socket to drive the bearing into place. The wall of the socket should be wide enough so it can contact both the outer race of the bearing, and the face of the bore. That's what prevents the bearing from being driven too deeply.

 

I would respectfully disagree with most of these comments and do agree with the referenced write-up in post 12 that the bearing should be driven home to the land. The dimension of the hub, inner spacer, and bearing inner races are such that the clamping forces provided by the collars on the inner races and inner spacer by the axle that is torqued to some 75 foot pounds results in a zero clearance fit. If the bearings are not fully seated then the 75 foot pounds of torque is either going to seat them completely by pushing on the inner races or put unwanted axial (thrust) forces on the bearings inner race.

 

I think the best way to describe it is to seat the bearings center race fully against the spacer to avoid side loading when clamped down. I don't think it's even possible to fully seat the outer race in the hub with the spacer in there.

 

the first side you install has room to go in fully.

 

True dat.

 

Dang. I totally forgot about the spacer. DOH!!

 

This has been a good discussion. I’ll just see how it goes!

For what it’s worth - I replaced the bearings as the OEM ones felt very stiff (and were obviously old). Upon extraction, they moved as smooth as silk in my hands. Go figure.

 

I want to revisit this after thinking a bit more. The spacer is machined to fill the gap between the bearings, and the bearing bores are machined as the baseline that defines that gap. After reflection of how things worked out when I last changed wheel bearings the bearings were flush with the face and the spacer was snug against the inside of the inner races of the bearings. There is a small gap at the back of at least one (and maybe both) bores. I know this because I did drive a bearing in too far and had the dragging issue that the OP described (though this may, or may not be, the cause of his problem).

OP. Though it is uncommon, new bearings can be faulty. Did you run the bearings by hand to check for smoothness before you installed them? I'd also like you to be sure that the drag you are encountering is not due to the brakes, or fork misalignment. Could you check with the brake calipers removed from the fork? When reinstalling the axle, in what order did you tighten the fasteners?

 

The wheel is completely off the bike for refurbish. The new bearings were smooth out of the package, so it is definitely a spacer issue. The inner races now a bit stiffer with my finger in there, but seems to spin ok on the wheel when I’m holding the wheel up with a finger in each side

 

Well not a spacer issue, there's nothing wrong with your spacer. You just knocked the bearing in a bit too far and the spacer is putting pressure against the center race making it stiffer to spin. If it spins okay and isn't grindy/clunky feeling then I'd just run it, there is really no way to move the bearing back out without risking damage unless you can get to the outer race from the other side which is unlikely with the spacer and both bearings in place.

 

The spacer can be slid to the side (just as when the bearings were removed) and one of the bearings can be tapped back out a bit with a drift. Work slow, and evenly.