Steering head bearings question

I will be doing this on Friday.
I will take as little as possible off to accomplish this task.
I won't know until I get in there, I don't want to be obstructed either.
If I do have to drop the forks how do I make sure they are true when they go back on.
Haynes manual says "To ensure that the yokes align properly, slide the fork legs into position whilst the top bolt and pinch bolt are fitted."
Is the tolerance so tight that the upper and lower yokes will have to line up, there's no way they will be twisted?

Tightening up the "adjuster rings" looked simple.
I was already buying a socket to grind into the right shape for the ring slots.
Torque it to 18ftlb back it off a quarter turn done.
Then I realized that was for ball bearings.
So now I'm back to "tightening the ring sufficiently to remove all trace of free play, but no more."
So I wiggle the bottom yoke back and forth until I determine there is no more play left?
If there is a better way to do this let me know.

After everything is back together if I find there is still play I can adjust without taking it all apart again right?
From the Yamaha manual "When assembly is complete, check the steering stem by turning it from lock to lock. If there is any binding or looseness, readjust the steering stem tightness."

Thanks for any insight.
Houndy

 

IIRC you can just disassemble the top part of the tree to replace/service the head bearings, and drop both the forks out while they're still attached to the front wheel, leaving the bottom clamps tight. The only trick is that you have to jack the front of the bike up quite a bit.

If you can't find a real set of spanner wrenches to adjust the castle nuts, you could get some cheapo channel locks and grind the jaws flat

you can adjust the castle nuts when the whole thing is assembled, as long as the main bolt on top of the tree is loose.

as soon as you drop the tree out, ball bearings will go everywhere... I'm sure there are better ways to do this, but I just set up a "perimeter" around the bike with some shop rags or anything else that will stop a getaway bearing. :mrgreen:

 

I'd have a new set of roller bearings on hand to change out the balls. Odds are pretty good they are toast by now. Your adjustment technique sounds about right, run with it.

 

Thanks guys, I will get a loaner, spanner and bearing driver set from Auto Zone.
I am putting roller bearings in the head, the torque spec in the manual is for ball bearings, that's what I meant to say originally.
Good to know the forks don't have to come out of the lower tree so should be inline when they go back.
Thanks again

 

Well I did it on Friday.
I can't believe I'd been putting this off for so long.
It was cake and ice cream.
Organization was the key just like the carbs.
As I took it apart I put all bolts back in there respective holes, nuts and bolts back together in there spot.
A little time consuming but the next day when It went back together there was nothing missing and I didn't have mystery bolts laying around.

The front tire was off and the calipers tied to the top of the headers.
I started by taking the headlight out, unbolting the bucket from the mounting bracket.
Now the whole thing will come out and hang down on the forks.
The head light mounting bracket can stay attached, all wires can stay connected, except the turn signals.
Just use a sticky label to mark the wires in the bucket.
One signal is green the other brown and the black gets ganged into one common connector.
At this point you have a clear shot at the two nuts that hold the gauge package on.
A note here, the gauges as a whole weigh a bit so if they drop to the end of there wiring, they pull quite hard.
Take care that they are secure were ever you've got them hanging.
The two bolts that hold the ignition on can now be removed.
I now removed the two bolts that hold the distibution block/wire loom, for the brakes to the lower triple tree.
In hind sight I would have done this first so the whole mess wasn't hanging right were I was trying to work.
Now the handle bars come off and hang down the front with everything else.
The handle bars and all cables, wiring, attached to them will stay above the lower triple tree while everything else can be manuvered inbetween the forks, clear of them.
Upper triple tree comes off.
I would get a friend at this point just to make things easier.
Spanner nuts.
I used an ancient pair of channels locks that were very thin.
So thin that I could grab just the bottom nut.
I used a punch and a hammer to drive the top spanner nut around.
The first tap both nuts turned together, so I just backed them off that way.
Bearing cover removed, upper seal stuck to it.
I knew my bearings were bad but wow.
The races, which look like they're made of copper, had small depressions in them were the balls had sat, like the race was spinning with the bearings.
The grease was the consistency of bubble gum, that sat under a school desk for 27 years.
Slightly pliable, one step short of crumbling.
Here's were your friend comes in, while I watched the mess hanging down between the forks my friend pulled the forks, steering head, down out of the frame.
I set a four by four down and rested the bottom of the forks on it.
The top against the frame and motor.
Used a small prybar (10") to work the lower race off the spindle, making sure not to scrape or gouge it.
Put the same punch I used on the spanner nuts down through the top race and butted it against the lower one.
a couple good whacks and out it popped.
Put the punch up through the neck to the top race and popped it out.
Cleaned the seats for the new races.

The top bearing I was able to use the bearing driver set to press in.
The bottom was recessed to far for the driver to reach so I carefully tapped it in with a brass drift, making sure it was even all the way around as I drove it.
Packed the bearings with molly grease, hopefully it will hold up better then the dinasour grease that was in there.
Lower seal on spindle, then the bearing, it is tight at the bottom were it seats.
On a car you would just tighten up the crown nut and the bearing normal seats but I was taking no chances.
I used the same brass drift on the cage of the bearing lightly tapping around it until it seated against the seal.
Had my friend hold the forks/steering head up into the neck of the frame.
I put the top bearing in followed by the seal, had to jiggle the whole thing to get the upper bearing to slide down into the race, didn't want to push it.
Bearing cover on then the first spanner nut.
I tighthened it by hand until I could go no farther, friend can let go.
I checked for play and it seemed pretty tight.
I put those thin channel locks on the nut and turned, it turned super easy. So I continued to turn with the channel locks until it was snug.
You are only supposed to "tighten the ring sufficiently to remove all trace of free play, but no more."
I had no free play hand tighting but there is grease in there taking up space and I couldn't see hand tight being tight enough.
Had my friend hold the bottom nut with the channel locks, used the punch to drive the top nut around another notch and a half.
Top triple tree back on.
I would have your friend support the wire mess out of the way, while you attach the Brake distibution block.
This will help keep things up higher and easier to work with.
The handle bars can be set back in the clamps out of the way.
Remeber that gauge package set it back in the headlight mount.
Bolt up the ignition and the guage package.
Headlight bucket reattached, blinkers plugged back in with dielectric in the connection.
Here is the hardest part of the whole thing.
Put the headlight back in the bucket.
I swore and bitched for twenty minutes, the wires have all been moved around, no longer sitting pretty in there.
I could not for the life of me figure out what was in the way, holding it up.
I got it back on but, will revisit it when I have more patience.
Oh yah, put the clamps back on the handle bars and tighten.


While this is no text book writeup I hope if someone does a search my excperience with this job will help them out.
On a side note the PO had been in the forks.
The good, fork seals don't leak, the bad he must have lost four or five bolts.
He replaced them with metric bolts of the wrong pitch.
So when taking them out I thought they were siezed, put them in to discover they thread a couple turns and that's it with out totaly screwing it up.
After the first bolt I should have tried to tighten them all in but, I ended up making two trips to the hardwhare store. :evil:
I had to chase two of the threads to clean them up the others I was able to thread in no problem.
I fired Her up, checked all the electric I could think of, no issues so far.
I haven't had the chance to ride yet as it is in the teens for highs again and I want to buff up the wheels before they go back on.
Cheers!

 

I wish you had pictures but I understand how difficult it is when your hands are full.

How do can you tell if the bearings are bad? Head shake? What exactly is head shake? My bike doesn't behave squirrley or anything but I'd like to know all the same.

 

How to check:

Place the bike on the centerstand, and have a helper sit on the rear of the seat to put the front wheel in the air.

Crouch in front of the bike and grab both front forks toward the bottom.

Try to "wiggle" the forks fore and aft; there sould be no play.

Give the steering a gentle push to one side. It should fall to full lock smoothly, without binding. Return to center and repeat in the other direction.

With the wheel still elevated, slowly turn the handlebars lock-to-lock. You should feel no binding, looseness, or "bumpity-bumping" in the turning, it should be free and smooth. If there is a "detent" or looseness at the center, you probably need new bearings.

 

Cool, thanks Fitz. The bars are definitely smooth, lock to lock but I haven't done the fore-aft wiggle-check yet. I'll hit it this afternoon.

I'm looking at doing my fork seals. I have the Seca 750. My reading in the archives doesn't encourage me. This looks like another instance where I should score some ebay forks to practice on.

 

MY forks would "lock" in the center.
It took a good amount of pressure to get them out of the center position.
When I was taking things apart the forks never moved, all the wiring and gauges hanging on them, me moving stuff around, they never moved.
When I was reassembling, I had to tie things down, (gauge package) even bumping the bike would start the forks slowly moving to the side until they just flopped to the locks.
Smooth as silk.

I wanted to take photos and actually have a few but, my help was only available for a short time and I had to abandon the photos, to get it apart in time, sorry.

 

The 2 halves of the harness cross before they go into the bucket.
With the headlight removed, you can test the tripple trees for alignment with a square of plate glass, it should touch all 4 points without rocking.

 

Damn now you tell me. :wink:
I didn't have to remove the forks completely so it should not be an issue.
But that is a great idea I will remember it.

 

You can also loosen everything in the front end and then "snug" it back down, and BOUNCE the front end a couple of times. Then from the top down, re-torque everything. That will remove any minor bind/misalignment that you might have introduced with everything apart.

 

I happened to run into worn steering head bearing while tearing my bike down. I noticed the detent, when straight ahead and almost to lock, and didn't know this was abnormal til this thread (though it did seem odd). Sure enough, upper bearings were yellow and races scored.
I wonder if this is why it had a steering stabilizer on it. And why I never saw it in the manual.

 

The 1983 model (and ONLY the 1983 XJ750 Seca models) had a funky kind of "steering stablizer" on it.........

Are you sure you're isn't a 1983 model?

 

I'm pretty sure its an 82 - 5G2 - 1xxxxx 10 digit stamped vin and from what's left of the sticker is got a C in the year column.
This steering damper is a piston type mounted to the left fork tube by way of a bolted clamp, and to the frame by way of a bracket that also holds the horns.
This bike isn't stock, there are some other parts like foot pegs mounted through the engine bracket with the wrong bolts, and a suzuki headlight on it.

 

anyone have any pictures of said stabilizer?

 

1982 models start at "serial number" 100101 and run through serial number 149999.

1982 models start at serial number 150101.

According to the service manual and parts books, only the 1983 models used the steering damper, although it may be that they went into production later.

Additionally, I seem to recall somewhere reading about a factory "accessory package" (probably included the fairing) that used a steering damper.....

The letter "C" does indicate a 1982 model though.

 

I have an update:
I had some questions on installation of my bearings.
Chacal refered me to his manufacturer.
After talking with the owner, here is what I found out.
These tapered roller bearings should be torqued to between 15 and 25ft/lbs.
In this way you are using the spanner nut as a damper for the steering.
15ft/lbs being loose, 25ft/lbs being tighter steering.

I was still left with the problem of finding a socket to fit the spanner nut.
I could buy a 34mm socket and grind away what I didn't need. $15 for a socket.
a spanner wrench set $60.
You can buy an OEM socket for $40.
You can buy an adjustable spanner wrench $30.
All seemed a bit much for a one time tool.
So I went to the local bike shop and bought one of these, for $7 dollars.

It is a preload adjusting tool for your shocks.
The arc of the tool was to large so when I used it to torque the spanner nut it would slip off.
I thought about making a template and grinding a new notch part way through the arc.
Then my father suggested I just hold it to the nut with vise grips, brilliant.
So I just basically clamped the free end of the tool to the oppisite side of the nut.

I torqued mine to 20ft/lbs, it feels a little "loose" to me but, my old bearings were completely shot.
I will try it this way for awhile and see if it is just me or I need to tighten it down more.
Bonus is this tool works as a preload spanner on our bikes.
I through it in the little trunk with my rachet handle, extension, plug socket and spare plugs.
Not bad for $7 bucks.

 

When installing my tapered bearing using the tool suggested here: http://xjbikes.com/Forums/viewtopic/t=16281.html

and a spring scale, and 15 ft/lbs seemed pretty snug. It will slowly drag if you "push" it past center to the lock. 20 ft/lbs and the forks wouldn't drop at all.
This is with only the forks and front wheel on, no handle bars/brakes/gauges etc. Is a string scale and BrassCraft wrench not a good measure, or am I just reading the amount of drag wrong?

 

The Haynes manual suggests using a spring scale to torque the bearings.
It gives the set up procedure.
It seems it has to do with the length of the wrench and were the scale is attached to it.
Useing the tool in my post I torqued to 20ft/lbs, there is no play in the steering.
It is loose enough that with the bike on the side stand and the wheel straight out, the head will just fall to the side on occasion.

 

Maybe I packed to much grease? After moving the head around a bit and torquing it down to about 20 ft/lbs, I think I got the right amount of play. The steering head doesn't drop on it own, but it seems smooth and there is less weight on it with all the pieces missing.