Steering Head Bearings

[JuliusPleaser]

I disassembled my steering head last night, and I'm not sure how to remove the lower triple clamp bearing race. Will I need to remove the steering stem via a press, or should I cut the race off with a Dremel?

I'm working on the YZ250F, and the SH bearings are wasted. I left the bike parked for two or three weeks, and when I loaded it into my truck, I found that the steering head bearings were seized. :think: When i took it apart last night, there was NO grease in the bearings. Now I'm gonna have to take the whole bike apart. Dealer 'prep' strikes again.

 

[marcusgunby]

You need to press the stem out and then press the bearing on-most dealers will do this for a small charge as its a common problem.

 

[Jaybird]

Julius,
If you plan on taking the stem apart on a regular basis then you can use any good lithium based grease and be fine. But if you think you may not have time to do this often, I suggest you get a tub of wheel bearing grease as it will stay put much longer than a #2 grease will.
Once you have the new race and bearing pressed on, you won't have to remove it in the future for regular maint., just spray some degreaser on the old stuff...work it around a bit...and then blow it out with an air hose. Then just push grease back in with your fingers.
Good luck.....(btw...don't try top press the stem out with a hammer :) )

 

[JuliusPleaser]

A hammer is my second-favorite tool. . .right behind a BF hammer. But. . .I've learned to ask questions first, and hit things with hammers second.

My KTM has a nifty aluminum collar covering the upper head bearing. I may try to retrofit one onto the F. The steering head bearing seals on the F are really weak. Planned obsolescence, maybe?

I have a couple of different greases on hand, but i think I'll stick with wheel bearing grease.

 

[Jaybird]

I like those stem covers with the rubber rings too! :)

 

[SFO]

Suzuki has an oem tool that is a bearing seperator with a puller attatched for withdrawing the lower race.
Or get some liquid Nitrogen or dry ice and chill the race and crack it off with a hammer.
Careful if you remove the stem from the bottom t-clamp. I have seen this done poorly resulting in the clamp getting buggered up or thew stem not being reinstalled square to the clamp.
The yz-fs are known to get hot around the steering head via the oil in the frame which cooks the grease out of the bearings. If it wasn't regreased as part of your new bike prep all bets are off as far as longevity.
I installed a zirk in my steering head and just fill the steering head up with grease.
Hope this helps.
Bill

 

[Jaybird]

I've thought about a zerk there. Do you get a mess or does the seal hold it in pretty well?
I thought it may make me a bit over confident of the set-up and would tend to neglect the top bearing as it may not see grease from the stem housing for long even if full.

 

[SFO]

Yeah, when it gets hot it drools grease but I would rather clean grease off of the front fender than replace steering head brgs and races.
when I fill it I pump until grease comes out from under the top seal.
I know this sounds agricultural but hey...

 

[DEANSFASTWAY]

If youre real skillful with an air chisel you can burp out that lower inner race but first youll have to cut the cage off and remove the rollers . First off before you do anything you should wrap the triple clamp threads with electrical tape to protect the threads . At my shop I have two brothers in the area and when they both decided they neededthe trickest newset blue triple clamps for their scoots they tried to bang off the bearing with a sledge and chisel and they screwed up the threads real bad . Also anybody install an Applied clamp and have the new Yamaha lower bearing slide down with no interference? You dont even have to press it on 02 YZ125 . Iwas wondering if this was right . I ended up wrapping 002 shim stock around the shaft because he had to race the next morning. He hasnt been back since. SFOs got the right idea ZERKs are the bomb , you only usually see them on Enduro bikes ON CRs though you have to block off the frame tube holes , Spray foam insulation works good for that .

 

[JuliusPleaser]

I already removed the cage and rollers, but the race is going to be tough to get off. I have access to an air chisel, so I'll probably try that first.

I was a little surprised that the bearings are $30 each at the local Yamaha shop. That seems a little spendy for a roller bearing. Time to shop around.

 

[Jaybird]

Ouch, JP! Yes do shop around.
I've seen a little tool for air chisels that looks like a mini ball-joint tool. You may find one fo those and try it. Be very careful when doing this.
I've had luck in the past removing races by just a little heat then quickly prying with a screwdriver, but I've never tried it like that on a strearing stem. Most are aluminum and you would want to heat the race and pry VERY quickly as the stem will expand in seconds too.

 

[DEANSFASTWAY]

Hey Julius Pleaser that a cool name! By all means do shop around for those steering bearings on the HUSKY 250 I had in the shop last night the bearings were @$60 a pair . We didnt really question this until we went to put them on and they were wrong . Then we looked in the McMaster Carr book and crossed them over for $11 each . We were really pissed because the bike is tying up the works .Let it be noted that this was after a second trip to the Husky dealer who gave us a wrong piston and reeds . The piston was the dealers fault and the reeds were listed wrong in the reed application book but the package was opened and it looked like tried to pass them off to someone else only to have it returned . We didnt find out about the bearings until like 10 pm & it was too late . My advice to you Julius if you dont allready know is to learn how to cross over bearings and seals & stuff because these bikes always need them . Youd be suprised at what your local NAPA store /Industrial Supply Store can get for you .And you probably wont have to wait so long to order . Also parts unlimited /tucker rocky /k&l supply and stuff have steering head bearing kits available .

 

[jmics19067]

Jaybird,
I have succesfully tried that approach before ona few truck parts but have yet needed to try it on my bike, but it takes nerves of steel, lots of trust in the heat dissapating qualities of aluminum,and a bit of luck. With the race that is pressed on exposed < rollers and cage broken off> Use a cutting torch and just shave off the outside edge of the race ,burning a thin flat spot. With the race softened and thinned from the heat, the heat transferring to the aluminum and expanding strecthing the race it will come off relatively easy after it cools back down and aluminum shrinks back to normal but the race is still stretched.
I use this as a last resort when a press and bearing separator is not enough to do the job for a few reasons. 1 you have to be extremely quick and good with a steady hand. Burning steel I believe is at a temparature around 3500 degrees farenhiet when aluminum melts at 1400. Burning a hardened race is a lot different than cutting low carbon structural steel which is what I am used to, you can very easliy knick the aluminum with the torch or spot it up real bad with the slag being thrown from the cutting torch. As I said this is the last resort before before throwing all the involved parts away because you may just as well be doing that any way after trying this.
I have never done this with a steering stem bearing but I thought you might be interested in that.
For a steering stem bearing or any part along the same type of design where I can use a 4"grinder and grind the race paper thin in two spots,and then smack a thicker part of the race where you just ground away from the thin spot and just break it off with a hammer and chisel. This time it takes patience and a steady hand to be able to sit there grinding away at some hardened steel stopping often to inspect your progress closely Which is what I would suggest to J.P. if he trusts his steady hand . Again this is when the press and bearing separator won't cut the mustard or not available

 

[JuliusPleaser]

I'm taking the stem to a friend's body shop tomorrow to try the air chisel. First, I'll use my Dremel and a carbon fiber wheel to cut as much of the race as I can without butchering the stem.

I've wondered about matching bearings from Grainger or some other supply house. If I take my surviving bearing in, will they be able to match it?

What's a McMaster Carr book? :confused:

 

[Jaybird]

LOL...I'll tell you what a McMaster Carr book is....BIG...Try their website.
It is the same thing as Grainger.
Yes, they can match the bearing, go with the highest dollar bearing they have and you can probably buy two or three of them for the price that dealer wants. Can you read numbers on the bearing? If so post them.

 

[Jaybird]

BTW...those bearings are also known as "Timken" type bearings.

 

[Jasle]

Timken is a brand no? Pretty sure it is but Either way I have had great luck just looking up bearing in the yellow pages and dropping by the closest one. I found bearings for the kids Cobra throught them. One set I couldn't pull a number off of and they measured it and asked the application. when I told them it was part of the transmission they crossed it to a heavyduty high speed bearing and then sold me one the size I needed. $7 from bearing shop...$30 from Dealer.
Jason

 

[JuliusPleaser]

I've heard the name Timken before.

My steering head bearing has the name "KOYO" and the words "HI-CAP" and the number 320/28JR on the fat side of the inner race.

 

[SFO]

Both the inner and outer races normally have #'s
You also just measure the od of the stem and the id of the steering head.
The japanese part #'s also sometimes utilize the brg # in the # code.

 

[JohnScott]

Also, you might try going to a site that has part diagrams for your ride such as powersportspro.com. They sometimes list the bearing number on the part description which you can then call into your local industrial bearing supply house and they can get you the exact bearing for about 25% of the cost of an OEM. I do this quite a bit with my KTM and my friends KX's for wheel bearings, brake pedal pivots and swigarm bearings. I have not had much luck with shock bearings though.

John

 

[Jaybird]

Jasle,
Timken is a brand name, however they are the industry standard for tapered bearings and most companies own licensing rights from them to build these types of bearings. Timken makes all types of bearings, but when you call out a Timken type bearing, most bearing guys know what you want. Timken and SKF are quality, high tolerance products.

JP, are you certain about that number?

 

[JuliusPleaser]

Yep, i'm sure. I have the bearing here in front of me, and those are the only markings on it.

I can take a pic if it will help. I haven't checked the outer race. Will I have to remove it from the frame to check for a number?

 

[wrench]

JP, look in your phone book under "bearings" (as suggessted before) for NTN, or a NTN distributor. They will be able to help you with the number on your bearing. I saved $65 when I got the main bearings for my YZ from them instead of the dealer. They have a dist. center here in Norcross. You have to be a shop or dealer to by direct from them so find out thier part number and I'll pick them up for you.


wrench

 

[JuliusPleaser]

Thanks, Wrench. I have a friend here who does inventory control for Grainger. If he can't help me, I'll give you a call.

 

[Jaybird]

Julius,
All metric tapered bearings, or Timken type bearings, will meet ISO 355 standards. Just measure the inside diameter of your bearing(mm's) and how thick(tall...again mm's)it is. This will be a standard part and you can get one from any bearing distributor with that information.
I questioned the 320 designation on the Koyo, as a 320 series bearing is a big ole bearing that would be larger than what you have.
You will only want to purchase the inner ring and roller assembly, as you don't need the outer race. Leave it in there and just clean it up well with a scotch-brite pad.