One step forward, ten steps back…

[Mezo]

They are not bronze or anything, id guess they would be stainless or hardened steel elecrto coated with something similar to bronze to stop it binding against the alloy, im guessing the scratches will be partly due to the oil not being changed regularly & breaking down its properties causing the bush to loose its coating, steel rubbing against alloy with cause the alloy to wear (its softer than steel).

Mezo.

[ActionManMelb]

Still no measurements!

This type of bushing is very common in the automotive world. They have a steel backing and are then coated with the bearing material, which can be copper, bronze, tin/tead/antimony (white metal) or yes, even teflon over bronze, according to the application.

I want the dimensions so I can rummage through my catalogs and possibly find a drop in replacement.

[xtzrick]

2 x 55W bushes cut down will probably be ok, but it would call for some VERY accurate cutting.

If you give Actionman the mearsurements (34L & 55W) & he can find commerialy available alternatives, it would save forum members a bit of money!

Rick

[andylarkin]

Still no measurements!

This type of bushing is very common in the automotive world. They have a steel backing and are then coated with the bearing material, which can be copper, bronze, tin/tead/antimony (white metal) or yes, even teflon over bronze, according to the application.

I want the dimensions so I can rummage through my catalogs and possibly find a drop in replacement.

Action Man… Sorry, I wasn't being deliberately unhelpful, just forgot to respond. I can give you some measurements, but only from a ruler mate. I don't have anything as advanced as a micrometer. Would that be ok?

[andylarkin]

Form a normal steel rule:

55W OD = 41mm
55W ID = 39.5mm (as far as I can tell)
Height: 14.5mm

34L OD = 41mm
34L ID = 39.5mm (as far as I can tell)
Height: 19.5mm

The gap on the 55W is not even measurable it is closed up (but can easily be opened with a very gentle pull)

The gap on the very old and worn 34L bush is 1mm - I assume cos it is both old and worn.

There is a very, very moderate chamfer on each edge of both.

Is that ok?

[Mezo]

I don't have anything as advanced as a micrometer. Would that be ok?

Micrometer is mainly used by machinists for things like valve stems & guides where accuracy is paramount to withing a few thou, handy tool & relatively cheap tool is a digital vernier caliper.

With one of these you can measure OD & ID plus depth, where a micrometer just measures OD, last time i looked you could get cheapie chinese ones to your door for under a tenner, mine are donkeys years old pre LCD display but still work fine after 35yrs use.

Mezo.

[andylarkin]

Ok, digital measuring thing purchased.

Results are as follows (note the measurements were taken with the gap closed, as per the 55W NOS bushes that I purchased and not as per the tired old 34L ones):



Hope that helps?

And hope someone can suggest some replacements.

[Mezo]

Fantastic.

Now lets see Dave's cunning plan.

Mezo.

[Ténéré Mike]

OK, time for me to chip in. I hope I'm not too late!

What was your cunning plan ActionMan? Did it grow a tail? Oh, that's right - you're off to Ireland! You must have been busy packing. Enjoy your holiday...

Here's my "Six Pence" worth...

For starters: These bushes are steel backed and aluminium / copper coated before being given a layer of teflon (which IS PTFE). Both the upper AND lower are necessary or there will be so much slop in the fork leg you'd be better off putting the 'crook' old one back in. It is very unusual for the bushes to acquire the markings shown in the detail photo of the OLD one (both faces). This indicates some form of abuse during removal or storage or foreign matter in / on the fork tube. Ordinarily, if the dark grey coat is present all around the old part it can be reused. If there is ANY copper or aluminium showing through it must be replaced. If it ever gets to the steel, the fork lower will last about a 1000 km.
These bushes are precision formed similar to engine plain bearings - so don't try replicating them with your local machinist.

Next: Yamaha fitted all 34L / 55W / 1VJ / 3AJ variants (and global equivalents) with SHOWA forks - these are VERY different to the KAYABA forks fitted to the normal XT600. The 34L forks are a earlier generation fork to the latter models. The Way to distinguish the Ténéré fork from the XT600, externally, is that the Ténéré fork has a 8mm Hex for the damper tube and the XT600 has a 10mm Hex.
Yamaha didn't deal with SHOWA over any great period of time, so they have very poor parts support for the SHOWA forks.
The new bush you have looks like the KAYABA ones used in the XT600 (Kayaba use a different low-friction coating, hence the colour difference).

Now: SHOWA forks were used predominantly on Suzuki, Honda & later Harley Davidson bikes. These are a great source of CHEAPER spare parts for your Ténéré forks.
The bushes and seals from 84-88 vintage Suzukis with the same fork diameter fit right in. Same with bushes from 83-87 big Hondas. Both Suzuki & Honda carry piles of them.

So: I have used the following Suzuki '87 GSX1100F fork parts in my 39E (Pacific Version of 34L) for well over 20,000 km now without a problem, they are a perfect fit:

Upper Bush (in the alloy fork lower - I think Yamaha call it "Metal, Slide 2" 34L-23135-00) Suzuki 51152-48B31 (from GSX1100FP US model and a heap of others)

Lower Bush (on the bottom of the steel fork tube - Yamahas "Piston, Front Fork" 34L-23171-00 which isn't serviced in some parts books) Suzuki 51121-48B31 (from GSX750F 2002 etc etc)

Oil Seal Suzuki 51153-08D00 (91-93 GSX-R750 etc etc - this is a beautiful double lip, double spring seal with a low stiction design. It is 1000% better than the Genuine Yamaha seal.)

Dust Seal Suzuki 51173-15D00 (from 88-93 GSX1100 etc etc) Note: this part is a functional replacement only (IMHO, it is better at removing the dirt away from the leg). It runs the risk of pinching the fork boot when toward full compression. Use Yamaha part 1LN-23144-00 if at all concerned - this has an integrated outer metal rib to guide the boot over it (and hold dirt around the leg!!!).

I recommend using a SAE 15 weight fork oil at about 0.9 bar (12.6 psi) air pressure if you weigh over 100 kg, or SAE 10 and 0.5 bar between 80 and 100 kg

Also if you need the little studs at the bottom of the RH fork lower (that holds the axle clamp on) look for Honda parts from early nineties on [05-06 Honda XR650R - 90136-KA3-831]. Perfect. Yamaha and Suzuki don't service these.

I hope my hours of research and measuring bits at the local dealers helps you and others.

[andylarkin]

Ténéré Mike

YOU BLOODY GENIUS!!!

Thanks mate. Just checked them out and they are available… I am very grateful.

Re: the damage to my old bushes, there looks to be scratch marks on the inside of the fork legs… does this look like it is linked?



Would you say these legs are shot or, as the scratches are below where the seals sit, they can still be used?

I have also taken a snap of the part on the stanchions where this bush sits. Is this normal wear would you say?



And finally, the piston, does this look ok?



Sorry for the naive questions but I'm new to fork internals and it's a bit daunting. And you guys know what you are talking about!