what kind of lube does JVL use?

Dave – Have you checked out Garlock bearings? Po-Drive used them in their GN stuff back in the late 90’s. Turns out the part number in the Po-Drive catalogue is actually the Garlock part number. They were charging 80 quid per bearing (2 per tube)!! I think all of the main distributors sell them here for around $20 each BUT they no longer make them. Turns out there’s been some advancements in bushing wizardry and the nice rep at Garlock NA recommended a different series (DP4 or HX or something) . He transferred me to the receptionist so I could order some and when I told her how many I wanted she laughed because they really only deal in large lots! She asked me if I was doing prototyping or research…of course I said hell YES! Next thing you know she shipped me 10 bushings as a sample…FOR FREE! Then they shipped another batch on accident!

They should have what you need and if you tell them you work for Mazda you may just get some free shit!

http://www.ggbearings.com/

Andrew

Garlock = DU = what I posted there from Applied = no sizes in Dave's obscure oddball OD dimension.


That sucks, Dave. I don't think anybody makes bushings or round stock in 1.868 OD. That's a shitty design right there.

I think yer gonna hafta buy some bronze round stock and whittle it down on a lathe. Get enough to do this a few times if you plan on keeping the shocks and whittle down a nice long section on the outside so you have spares.

Then run a drill down the center to get it close and, yes, you're going to have to "size" them as JV says on the lathe once you press them in with a boring bar. Gonna need a REAL lathe to chuck up those lower tubes and with the ears on 'em...gonna be a tricky thing.

FWIW, Protrac uses commercially available sizes and the nice DU things with grease retaining holes and teflon coatings. I think they last a lot longer than regular plain bearings/bushings and are easier on the inner tubes.

---

Lurch
Eric Burmeister
The west coast...of Michigan

Dave,are the bushings in the shocks teflon coated? If so, they have to be a commercially available bushing.

I just got thinking, having revalved my KTM forks a couple months ago, mebbe they used a motorcycle part?!?

The plain bearings in those are tefon coated and are very thin...thinner than the Garlock things. They typicaly are cut on one side...like a piston ring.

You'd have to check the specs on bikes on the wienernet and find one with 45mm forks. Then call a dealer and if they have some in stock, bring your micrometer.

Just a thought.

Good luck.

---

Lurch
Eric Burmeister
The west coast...of Michigan

Symmco has a sintered bronse bushing, part number ss-5260-20, with a 1.879 OD and 1.629 ID. I think the strut tube can handle being bored out to fit that bushing (wall thickness only changes by .002" Then I can bore to fit.

Luckily, these struts are basically a threaded tube and the strut mount threads on, just like the spring perches. All I need is a conventional lathe that's not out of round and has sharp tools... Hmmm, still might be farming this one out.

I still don't know how I can tell the difference between a soft sintered bronse booshing that will lose interference fit and the nice, hard ones JVL's guy finds under the counter...

Good call on the fork parts. They are teflon coated (should say WERE, now they're half teflon coated) so they should be available somewhere. I've got a good motocross shop nearby, I'll try to check there today. They are seamless bushings, though...

-D



Edited 1 time(s). Last edit at 11/21/2008 07:39PM by eyesoreracing.

Hit two shops today. KTM shop said all their forks are 43 or 48mm. They suggested Honda. Honda shop had something with exactly the right dimensions, but it was split, and the teflon was on the OUTSIDE. Seems the forks are built a little different from an inverted strut after all.

I've never had a motorcycle fork apart, so I don't know much...

-D

Yo Dave, call Pro-Parts or email Craig. I'm thinking the Koni 28 struts are 45mm, and if they aren't and you need shock-specific lathe work, Pro-Parts would be able to do it.

Andris

Andris!?! I didn't expect to find you lurking around here. Are you secretly building a rally car, or did that "lube" title bring this up on Google when you were looking for something else?

Thanks for the idea. I just fired an e-mail over to Craig and Guy. It's another long shot, but worth a try...

How's that Miata running?

-D

Hey, JVL, have you ever thought about using split bushings like the Motocross guys do and holding them in with little wire snap rings? Just thinking it might make servicability really slick and easy and would be a great poke in the eye to the DMSes of hte world. I know that last part would be fun for you...

-D

You got me, it was the lube.

I wish I was secretly building a rally car - I'm just lurking because I have a soft spot in my heart for rallying, and the car construction threads are more interesting than most roadrace stuff.

Miata's good, but I haven't had much time to work on it lately; I recently opened my own shop in TX which is keeping me from playing much.

Good luck with the bushings!

Andris

eyesoreracing Wrote:
-------------------------------------------------------
> Hey, JVL, have you ever thought about using split
> bushings like the Motocross guys do and holding
> them in with little wire snap rings? Just thinking
> it might make servicability really slick and easy
> and would be a great poke in the eye to the DMSes
> of hte world. I know that last part would be fun
> for you...
>
> -D

No but there's plans afoot to thread the ID on the bottom and screw in the bottom.
Then to service bushies, just pull a groin muscle talking the bottoms out, and it's an easy press.


Ya know? I could do that on existing things at service time and I could do it on DMS when they go to a different insert, or rebuild the units using Bilstein internals like that guy I suggested he try it. Well it worked and the parts are cheap, and who cares if you loose the adjustie thangs, 88.76% of the time they're seized solid.

See what I's saying? Say you have some whupprd DMS.
Rebuild internals with B46 Bilstein stuff, bore the bottoms of the tubes, thread press out dead bushes, press in new and assemble.

As long as the bottom tubes aren't utterly shot on the ears, I could make it work.

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Well, that's a hell of a lot easier than cutting the old bushings out and pulling them out the top, but it still requires a press and a pulled groin muscle. If its possible to do it with motocross-style bushings so you can remove the bushings with your fingertips, it would be a lot easier for the under-equipped guys you cater to most.

Of course, I've never had a fork apart, so I don't really know what I'm talking about, but I was impressed that the guy at the Honda shop tried to pull my bushings out with his fingertips before he realized they were press fit...

-D

eyesoreracing Wrote:
-------------------------------------------------------
> Well, that's a hell of a lot easier than cutting
> the old bushings out and pulling them out the top,
> but it still requires a press and a pulled groin
> muscle.

No muscle pulls for a buffity young dude like youse, I was thinking of old grizzled all stove-in ME!

And is a press such a problem? They have the at harbor freight for a hundred bucks!


If its possible to do it with
> motocross-style bushings so you can remove the
> bushings with your fingertips, it would be a lot
> easier for the under-equipped guys you cater to
> most.
>
> Of course, I've never had a fork apart, so I don't
> really know what I'm talking about, but I was
> impressed that the guy at the Honda shop tried to
> pull my bushings out with his fingertips before he
> realized they were press fit...

I've serviced my forks and they WERE bushes just like I use, I have no idea what the split, loose bushes you're talking about; sounds like a pain to make.
and expensive.
I ain't RSSVP.
>
> -D

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Some of the fork bushings can be split and retained by a snap ring because they're actually more of a hydrostatic bearing than a regular bushing. They don't work without an open oil bath to supply the hydraulic wedge and keep the slidy bits separated. It dramatically reduces the stiction in the fork down to basically just the seal force.

-Tim

That's starting to make a bit more sense. Where does this oil bath live? Is there just a seal above and below the bushing with a little oil trapped between, or is it more complicated than that?

-D

It's less complicated...on a conventional fork it's just splashing about inside and is the same stuff that goes through the valving. Same deal on inverted forks except gravity keeps the bushing submerged so they generally use less oil. It would be very difficult to replicate on a rally strut so everybody just went to rollers instead.