A forum for owners of Yamaha TTR250 trail and enduro bikes!

TTRfan · Super Guru

Swing arm bearing replacement

TT-R250M · Super Guru

Can you use a breaker bar (to save damaging the extension bar) long extension bar and socket (that just fits inside the swingarm) and hammer to drift it out from the outer race of the bearing?

TTRfan · Super Guru

That might work Jarrah - I will give it a go another time.

I have managed to get the bearing out using a combination of strategies.

First off I used a worn (therefore small diameter) cutting disc in the Dremel to put a cut in the bearing shell to weaken it.

Swing arm bearing removal 001.jpg

I then had a go at it with a small sharp cold chisel and hammer. The bearing casing is very hard and I managed to shatter a few pieces off and weaken the bearings grip on the swing arm just a tad. I then got the blow lamp on the swing arm housing and got it as hot as I could. I then sprayed WD40 onto the bearing shell to shock it and further help "crack" its adhesion to the swing arm.

There was just enough of a lip left on the inner edge of the bearing for the drift to catch on and this time it was possible to drift it out quite easily.

This is the outside edge of the bearing:

Swing arm bearing removal 002.jpg

This is the inside edge showing the lip that I had left to get the drift on.

Swing arm bearing removal 003.jpg

The swing arm is now fully stripped and power washed (not a nice job as it's very cold here today) ready for rubbing down and spraying.

Hopefully fitting the new bearing and seal kit will be the easier part of the job wink

To be continued.....

Brian

TTRfan · Super Guru

Ok - so I tidied up and sprayed the swing arm and today set about fitting the new bearings. Took a bit longer than expected as I also rebuilt the linkage arm at the same time.

I use All Balls kits and the pic below shows what's in it. Shame they don't include the end caps as the RH one on this swing arm had started to get chewed up by the chain as the chain slider had worn through However, knowing this, I keep a small supply of new ones in stock biggrin

Swing arm bearing fitting 002.jpg

The pic below shows the worn out chain slider and you can just see on the swing arm end cap wear the chain had started to chew into it.

Swing arm bearing fitting 009.jpg

First off is to fit the bearings in the swing arm and I do this by squeezing the bearings in as far as I can using the vice. You will see that the bearings have different shaped "ends" and I assume that you are meant to push the bearings in using the wider "flat" ends.

Swing arm bearing fitting 003.jpg

I have an aluminium driver that does the job perfectly but used to improvise with sockets.

Swing arm bearing fitting 004.jpg

The bearings are recessed by about 3mm - not sure why but I press them in as Mr Yamaha intended!

Swing arm bearing fitting 005a.jpg

Swing arm bearing fitting 006.jpg

It makes life easier to refit the linkage arm before the swing arm.

Swing arm bearing fitting 010.jpg

There will now be a slight delay whilst I clean up and re-attach the swing arm fittings and I will then finish this thread off.

Brian

Lostboyscout · Veteran Member

Here's a few pics from noeyedear on his approach to easing the bearing races....
Gentle heat over the shed stove...he had to move the kettle I see! Lol

TTRfan · Super Guru

I put the swing arm fittings back on but forgot one important item (because I had thrown away the old one and there wasn't anything in the box) and that was the chain slider disbelief

OK, so on with the job in hand. Having fitted the bearings in the swing arm, I added extra grease and slipped in the bearing tube. The next job was to put the big washers from the kit into the end caps and, using plenty of grease, popped in the seals. I find it easier to put the seals in the caps and then fit them to the swing arm as they are quite a bit chunkier than the originals.

Swing arm fitting 001.jpg

Swing arm ready to fit. Make sure you fit it the right way up as it fits both ways. I wasn't wide awake this morning (TRF social at the pub last night disbelief ) so put mine in upside down and had to take it out again!

Swing arm fitting 002.jpg

Push the bolt through from the RHS, fit the nut and washer and torque it up to a hefty 105Nm.

Swing arm fitting 003.jpg

Fit the link arm to the swing arm and torque to 59Nm.

It was a bit of a faff fitting the chain slider with the swing arm in place but it was possible and saved taking out the swing arm pivot bolt and re-torquing it.

Swing arm fitting 004.jpg

Job done and cuppa time biggrin biggrin biggrin

HINT - try to do the job in one hit to save misplacing or forgetting parts!

Brian

ttboof · Super Guru

When doing my swingarm bearings the second time, I fitted a grease nipple in the swingarm and, before tightening the main bolt, I pumped in grease until it came out around either end. Now it's just a case, now and then, to give a careful top up (as it might be possible to pop the seals out ). No signs of any wear after 2 years of riding wink

TTRfan · Super Guru

I had to fit another set of swing arm bearings and seals today so tried refining my fitting process as my vice doesn't open wide enough to easily accommodate the swing arm, bearings and sockets needed to press the bearings in cry .

I used a length of 10mm threaded bar, two large washers, one 17mm Nyloc nut, an ordinary 17mm nut, and a 21mm 1/2" drive socket.

I fixed the Nyloc nut onto one end of the bar and then threaded on the washers and bearings as shown in the pic below. It's important the the "square" end of the bearings are on the outside to give a good surface to press on.

Tighten until the washers are flush with the swing arm.

A socket was then needed to push the bearings in a further 3mm.

Job done!

I would like to make a few improvements to the system as follows:

1. Weld a nut on one end of the threaded bar as the Nyloc started to turn under pressure.

2. Make up a couple of proper aluminium collars to hold everything central and allow the whole installation to be done in one go. See below - just need to find someone to turn a pair up for me. The measurements aren't in proportion as I took a pic of an existing drift to help illustrate what's needed. Anyone have a lathe and do a swap for a made up pair for some TTR spares? wink

The collar would need a 12.5mm hole through it to accommodate a bigger threaded bar if that was found necessary.

Brian

oshanrube · Veteran Member

hi, im trying to remove my rear swing arm and i got the nut loose. but the bolt wont slide. i tried hitting with a hammer but no luck. im wondering is there any other tricks to it? or do i just need to hit it harder?

oshanrube · Veteran Member

The seems to be a some sort of a tab there.how cani remove it or rotate the bolt?

oshanrube · Veteran Member

The seems to be a some sort of a tab there.how cani remove it or rotate the bolt?

ttr steve · Super Guru

Hi Oshan

That is normal and you can't rotate the bolt from that side.

Have you tried applying heat and then cooling then applying heat again? This may help free up a rusted in bolt. I spent nearly 2 hours getting 2 engine bolts out the other day cry and only the heat would get them out.

Steve

JOHNYBOY · Super Guru

air chisel with round bit works on rusted bolts its the vibration that does it