DISCLAIMER: The modifications described in the following text are for educational purposes only. In no way do I recommend that you apply these modifications to your own motorcycle. If you do choose to go ahead and modify your motorcycle based on the information in this document you will accept all responsibility for your own actions. The author(s) of this document, and host(s) providing it for you, accept no responsibility whatsoever. If you are unqualified to make any of the changes described herein but are bent on doing the modification, seek out a knowledgeable friend or professional mechanic for assistance.

Replacing the bottom shock bearing on a Yamaha TTR250

I did this with the suspension relay arm still in place and can't make up my mind as to whether to do it this way again or next time take it out and do it on the bench!

This job ranks in the "slightly more difficult" category but is well within the capabilities of someone with patience! Just follow this step by step pictorial guide.

Tools needed:- 27mm and 17mm sockets, a small portable vice or some sort of strong press, wheel-nut spanner (24mm), a tool with a hard fine point, and a plain screwdriver. And, if you are unlucky, a blowtorch!

Parts/supplies: All Balls kit ref 17-8613 - available from Totally TTRs

Clear a space and get the bike up on a stand and remove the back wheel to give room to work and let a bit of light in.  My advice is to remove the rear wheel to allow the swing arm to drop down far enough for the bearing in the relay arm to be clear of the bottom of the shock absorber.  I started the job with the wheel in but had to remove it partway through as I will explain later.

The All Balls kit with all you need to do the job.
 

Remove the retaining bolt.

You will then get a good view of the seals, circlips and bearing that have to be removed.
 

Prise out the two collars and the underlying seals - they come out very easily.
 

The wire circlip was a different matter. I found it very difficult to get anything underneath it to prise it out. This is where I resorted to removing the rear wheel to give me more room and a bit more light! After a real struggle I managed to get an edge and pull it out with pliers. I decided to leave the other circlip in place as it is possible to remove the old bearing without disturbing it.

Someone else who did this job recently hit the circlip with a punch halfway around its circumference and it bounced out of its groove. This may be worth a try if you are struggling.
 

Not a pretty sight. This is what was left of the circlip I removed - just as well there are new ones in the pack!
 

The next job was also a bit of a challenge - removing the old bearing. It was in very tight so I had to use a small vice. Use a 17mm socket to press against the bearing on the chain side of the bike this is of smaller diameter than the circlip that has been left in place.
 

Another picture of this very awkward process. The bearing was incredibly tight and I didn't have the strength to tighten the vice any further so, at this stage, I resorted to getting a propane blowtorch and within a few seconds of playing it on the shock body there was a loud bang and the bearing moved - thank goodness!

I have arrowed where I used heat to initially get the bearing to move. Once the bearing has started to move it is necessary to add the 27mm socket into the "press" process as this is just big enough to fit over the bearing. It was then just a case of tightening the vice until the bearing fell out.
 

Another view of the "press" process. I have arrowed where I used heat to initially get the bearing to move.


Bearing housing all free and clean and ready to receive the new bearing.

This is the old bearing parts. You can see clearly where the bearing had worn through its case hardening.



I mentioned that I had to use all my strength on the vice. Well, I was surprised that I had managed to bend it!
 

I used the socket "press" to squeeze the new bearing in and up against the circlip. Be careful not to go too far and start to push the circlip out. Not likely as it is fairly obvious when the bearing is fully home as you can clearly see the groove where the new circlip has to be fitted. All Balls suggest using good waterproof grease or else any good bearing grease as their bearing is steel-on-steel.

Next fit the seals - an easy push fit.

Fit the new collars next. Again, easily done by hand.

Replace the bolt and torque it up. Put the rear wheel back in and ....

Job done!

Brian Sussex
 

http://www.totallyttrs.com/ - everything you need (possibly!) for your TTR250
http://www.ttr250.com/ - all you ever wanted to know about TTR250s
http://ttr250.activeboard.com/ - the forum for TTR250 owners
http://www.totallywrs.com/ - for all your WR250R and WR250X after-market parts and accessories