Fork rebuild - internal bush replacement

striker · New Member Joined: Jul 04, 2008 Posts: 7

G'day all, I hope we have some front suspension experts out there today . . .

I have a 1979 Special (SF) which I am slooooowly converting to a Cafe Racer. I have recently had the stanchions re-chromed and I am about to have the fork lowers clear powder coated after a bead blast. Before I do that though, I wanted to replace the tired-looking bushing which sits just below the oil seal. But there's a problem of course :o)

I have checked the parts manuals for all XS650's of all years which used the 35mm forks and have not seen any of them which had this bushing present. That means I can't get a genuine Yammie spare as I can't get a part number. Neither can a dealer as they are working from the same parts drawings.

So here's the question. Does anyone know what alternate part, from *any* source would suit this application???

Any help much appreciated -

Striker

xsleo

at this point all you might be able to do is remove the one in there, measure it and get a machineist to make another one to match the fork tube. the only thing is knowing how much clearance you need.

striker · New Member Joined: Jul 04, 2008 Posts: 7

Ta for the suggestion. I had thought of that but there are two problems with it:-

1. Removing the bush would most likely destroy it as it is an interference fit and it is made of what looks like bronze.

2. The bush has ( had ! ) a coating of teflon. I don't know how thick it was or, for that matter, how a new buch would be coated with a new layer.

I was hoping someone had previously come across this problem and found a bushing from a Yamukinda 2000 would fit. A long shot, I know, but I had to ask :o)

jralex

Striker, If you haven't re-assembled yet, they don't show a replacement bushing on their website, but have you tried calling Racetech? 951.279.6655

striker · New Member Joined: Jul 04, 2008 Posts: 7

Ta for the suggestion but I managed to find a NOS set.

I have since discovered "The World Of Dremel" - why didn't anyone tell me those things are sooooo useful??? I bought some tiny cutting disks and carefully sliced up the bushes until they came out. Though there are a couple of places where I went through the bush into the aluminium of the fork, I reckon it is minor enough not to worry.

Now all I need do is get the forks powder coated in clear, replace the bushes and I'm done . . . and I'm sure it will be that easy ;o)

Thanks for the input guys !

jralex

I am rebuilding too. Racetech does not have these bushings. Can you give me any contact on where you found these.

striker · New Member Joined: Jul 04, 2008 Posts: 7

I sourced the NOS bushes from Tamor Trading here in Australia. I spoke to the owner and he said that he is slowly winding down his parts business. He doesn't buy any more, so when he is out, that's it. I believe I bought the last set but I may be wrong.

It's worth noting that many spares will fit, even though they don't have the exact correst part number. I did much research and found other Yammie bikes which had 35mm forks, then found all the bush types that were available for those bikes (the Yam parts website is brilliant but does not cover this part very well) and checked dimensions for what I needed. It took a while!

This is the reply I got when I asked for dimensions. The supplied part number is also given. These parts are difficult to find, so persevere!

I hope it helps.

1H3-23125-00 Slide 35.1mm I.D. 39.1mm O.D. 2.0mm Wall Thickness 11.9mm Height The inside only of the slide is Teflon coated.

striker · New Member Joined: Jul 04, 2008 Posts: 7

At loooong last I have fitted the new slider bushes into the fork lowers - and what a drama it was. I'm glad I wrote a bit sarcastically in my posting in February!

The bushes appear to be made of sintered bronze and I treated them carefully as I really didn't want to damage them. To fit them I put them in the freezer for a day or two and in the meantime cleaned the fork lowers thoroughly. I also had to carefully file off a couple of burrs caused by the heavy handed extraction method <cough>.

ost bearings have a fair bit of mass, so they stay cold for some time after removing them from the freezer. These little suckers are quite light and soon warmed up, even in the middle of a cold Australian winter's day. The bushing seemed to be a VERY tight fit into the slider. I could see I was going to have to break out the "Percussive maintenance tool". To avoid damaging the bushing I wanted to find something which would support the inside of the bushing as well as sit properly on the outside edge so I could hit it confidently. By sheer good luck I happened to have an old piston from a single piston caliper which fit like it was made for the job.

The final fitting took a LOT more bashing than I would have thought should be needed for such a delicate seeming part but it went in straight and is now seated properly. I suppose Mr Yamaha did this a better way when he made them . . .

I don't suppose many people will need to do this task (partly as the bushings are so hard to find) but if you do, now you know how to do it without destroying anything - just get an old brake piston :o)

Striker

Mikesxs · Full Member Joined: Feb 06, 2007 Posts: 134 Location: FL

Bushings are known as "DU Bushings" and are commonly replaced on upsidedown forks. I have never been able to come up with a number for them and have asked Japan to supply - the answer ? We are too busy making them for new bikes ( larger sizes ). And yes they are a real difficult install on new bikes also.

Mike @ Mikes XS

What Happened to 650rider.com?

Yamaha xs650