Unitrack service

Got questions? We got answers....
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Unitrack service

Post by canyncarvr »

I've had it with the bottom shock bearing on these things.

Mine was toast again.

I have a hunk of teflon that I got from my brother-in-law (let's call him Marty!). He's a diesel mech.

Marty thought it would be worth a try to get some of it machined to replace the bearing/sleeve/seals. They use it for sliders on dump beds. He's never seen it wear out.

Don't know how it will work as far as load capacity and such. It's not going to be very thick. I can put a bolt thru a hole drilled in the stuff, smack it sidways with a sledge and 'pooch' it.

Hope I don't end up with a goobered unitrack! I'll keep an eye on it, maybe catch that before it gets bad...if that's what happens.


I've serviced my suspension as often as 4X/year...and this bearing is usually wasted. I'm tired of messing with it.

...that and the $30 or so it costs to replace it all.

I'll probably get a few of them made. If anyone is interested in trying one of 'em, let me know. I'll send you one.

Oh...the teflon is GREEN. THAT'S gotta be a good sign, doughnit?

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

I'm doin' a complete teardown and I'll give it a go! Hell CC... if it works... you may have a new product! :wink:
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

Mr. Moderator:
Cc: Rethnal
Cc: Inda

What bonehead posted this here? Shouldn't it be in Q&A?

I mean...like...isn't this for parts diagrams and stuff?

What?? Can't the guy have two forums open at the same time and keep track of what goes where?

Maybe somebuddy kin moove it? :oops:


Oh...I don't know if the machinist I have in mind is around about now. It may be a few days before I get ahold of him. If he says it's a go, I'll send 'ya one!

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
dave04kdx
Supporting Member II
Supporting Member II
Posts: 256
Joined: 01:01 pm Nov 09 2004
Country:
Location: Casa Grande, Arizona

Post by dave04kdx »

Hi Carvr

If you can't get ahold of the machinist, I'll machine a few of the test bushings for you. I can do them at work and most likely get them on the way back to you the same day I get the material. I don't have any teflon stock, but I have tons of UHMW (ultra high molecular weight) and Delrin I can make a test bushing from if you want to go that way. I have used the UHWM and Delrin for all kinds of applications like your bushing and they have an extremely high wear life. I made chain rub guides for the swing arm on my 88 out of these materials and they show no wear at all after 1 1/2 years.
At age 4 success is . . not peeing in your pants.
At age 12 success is . . having friends.
At age 16 success is having a drivers license.
At age 35 success is having money.
At age 50 success is . . having money.
At age 70 success is . . . having a drivers license.
At age 75 success is . having friends.
At age 80 success is . not peeing in your pants.
89kdx200rdr
Supporting Member III
Supporting Member III
Posts: 245
Joined: 04:06 am Nov 16 2004
Country:
Location: Blountville, Tennessee

Post by 89kdx200rdr »

whoever makes them if they use delrin i will try one. let me know i will pay for it
1989 KDX 200
2003 KX 250
2006 KX 250F
User avatar
skipro3
Gold Member
Gold Member
Posts: 4329
Joined: 11:58 pm Nov 04 2004
Country:
Location: BANNED FOR LIFE!!
Contact:

Post by skipro3 »

Sign me up! Hell, I try anything once, I'm from California!!! :supz:
No, not that :butthead:
CC, If you make me one, hang on to it and I'll pick it up when I visit ya. I have a friend who made his own leafspring bushings for an extreme 4X4 but I don't know what material he used. Poly....something or other. I know it took a pounding. Anyways, if you can send me a drawing with the dimensions, then I'll find the stock he used and have a few made out of that stuff. We have a complete machine shop where I work with a few guys into making their own 4X4 parts and such. I've done them a few favors so they should be able to do this for me.
Jerry

I'd rather be a smartass like carvr, than a dumbass like.... well, you fill in the blank!
User avatar
m0rie
Supporting Member I
Supporting Member I
Posts: 2220
Joined: 10:25 pm Nov 29 2004
Country:
Location: Crescent City, CA

Post by m0rie »

CC, i'll give one a try if you want to send it down this way.

-Maurice
1989 KDX 200
2007 TTR-50E
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

Thanks for the replies.

The more severe the application, the better. If you service your unitrack once a year and never have to replace the shock bearing....why bother?

The machinist has my stuff. He has some nylatron he thought would be better suited: Read about it here!

I had proposed making a single piece to replace the existing bearing AND sleeve. I hadn't thought that out too well.

Make a bushing that is the 'correct' length and it will stick out of the knuckle. Squeeze it between the shock fork when tightening the lower bolt...and what you end up with something that isn't moving at'all!

So...he's making a bushing from the nylatron (grey/black) AND a stainless steel sleeve that will be the 'correct' width.

The oem setup gets you .020" slop between the shock fork and the knuckle and .010" between the bolt and the sleeve. He will tighten all those up a good bit.

I'm getting three made. When it's all done it won't be any less expensive than replacing the whole mess...but hopefully I won't be doing it three times a year!!

Ski: I can send you the measurements.

dave: Have you already replaced your shock mount with a bushing? Heck...I've asked about this a few times over the years and never did find anyone that had actually done it. Nylatron should be tougher than Delrin, I'd think. That may or may not be a GOOD thing.

I do think I'm going to make me a little mud flap to keep crud off'a that joint.

So...who has the worst luck with this joint? Whoever does gets one.

Let the stories begin...........;)

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

This year will be the most severe yet for me... steppin' it up a notch over last.... mainly because everything will be fresh, unlike last year.... :neutral:
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
User avatar
skipro3
Gold Member
Gold Member
Posts: 4329
Joined: 11:58 pm Nov 04 2004
Country:
Location: BANNED FOR LIFE!!
Contact:

Post by skipro3 »

All I do is pull a bolt out, wipe it off and look at it. No sign of corrosion, the grease is still clear blue in color, looks like I just did a regrease yesterday. That's all the hardware holding the shock and the swingarm as well. Then I just regrease the bolt slap it all together, and wipe off any that escaped. Oh, while I have everything apart, I do exersize the full range of motion on all the suspension pivots just to see if there is any felt slop. I can't detect any. My old 1984 KDX was another story. When I had that, I couldn't go more than 90 days without feeling slop. On a bike stand, I would grab the rear wheel and jerk it up/down and left / right. It would pivot and move all over the place!
Where I have trouble is the rear axle. I've changed those dang bearings about every other time I put a new tire on. 3 times in a year!!! For some reason, water finds it's way in there and the grease finds it's way out.
Any tips on a source for bearings and dust covers?
Jerry

I'd rather be a smartass like carvr, than a dumbass like.... well, you fill in the blank!
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

My tip is to use a good bearing to start with.

...and put 'em in right.

CBR bearing will sell you a lifetime warranted bearing set with seals for something like $45. More expensive than the junk you get from Kawi or some other aftermarket folks...but they last longer, too.

..and then you get free replacements!!

Give 'em a try.

BTW...If all I did was pull the bolt out and look at it I'd never replace the thing. The bolt ALWAYS looks fine. But...check the sleeve to bearing connection and you will find it's a rusted mess.

Well...in my case.

Really...you aren't serious about 'just pull the bolt out...' right? Say it isn't so!!!

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
KDXGarage
KDXRider.net
KDXRider.net
Posts: 14047
Joined: 06:45 am Nov 01 2004
Country: United States of America
Location: AL, USA
Contact:

Post by KDXGarage »

OK, since he got onto you first, NOW I will jump in. :-) You really should take it all the way down. I like to break out the old toothbrush and some kerosene and clean them real well in a little plastic pail. I bought a white plastic pail from Wal-Mart that is going to let any dirt or junk show up real easy in the wash and rinse stages.

Those strut heim bearings on the '84 and other link style KDX's sure do wear fast.

canyncarvr, how many thousands of miles per week do you ride? You get the Iron Butt award!
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

Is that the same as a harda$$?

OK..I humbly accept!! ;)

Got the link back today. I'll be posting some pics in the gallery...and Ski!!..the specs of all the pieces.

But...those specs are only good for this stuff. Mike (of Barnum's Machine) had to give it a few go's to make it all work. Stuff like...the outside diameter of the nylatron for the correct 'press' fit..and the corresponding correct measurement of the inside diameter that would give a correct 'crush' fit for the 302 stainless sleeve. He said it worked out kind of odd...that usually a metal piece is about the same oversize for 'press' and 'crush' fits, a .001" or two. This stuff took a .002 or 3 for press and a .007" for 'crush'.

It all looks real good. Am considering looking for a couple of shim washers to fit on the outside to shield the joint of the 302 and nylatron. I still need to measure up the diff between the unitrack and the shock fork to make sure I get something thin enough to fit.

...and there's still the 'mudflap' idea.

Altogether was $80 for three sets.

I still want to hear from someone that has had repeated bearings in this spot (lower shock) so there will be a decent reason to even try this thing out.

Mine's going in tomorrow night! YEEhaW!!

Will put it together with permatex anti-seize for good measure.

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
skipro3
Gold Member
Gold Member
Posts: 4329
Joined: 11:58 pm Nov 04 2004
Country:
Location: BANNED FOR LIFE!!
Contact:

Post by skipro3 »

Well, I'll be honest here, the only time I've ever taken EVERYTHING apart on the rear suspension is when I tried to get a KX rear shock to fit on it. At that time, I found everything to look almost like new condition, so I just regreased with waterproof grease and tossed it back together. Once every couple of months, I pull the lower bolts and check the grease on them and stick my finger in to feel the needle bearings. Still looks and feels like new and everything moves like it should.
Now remember, 99% of my riding is in very dry conditions. Not at all like Oregon, or heaven forbid, Alabama. When it does rain here, the soil drains very quickly and there's not much mud going on. Even water crossings are rare and then it is in a granite stream bed, no mud. Even when it snows, it's usually snowing on dust. We got 3 to 5 feet of snow a few weeks ago and not a drop of precip since. I drove some dirt roads today that alternated between raising dust clouds and getting stuck in snow banks. Humidity is at 17% today. Makes for dang chilly nights, I'll tell you what. Hi temp today was 28 and lows below zero, but with the humidity that low, stand in the sun and I need to strip down to a tee shirt to work outside. Air temps have not been above freezing but the solar energy evaporates the snow without melting into water.
My air filters are another matter. Due to the dust, I take 2 when I go riding and change it out at lunch break. I keep one stored in my fanny pack all ready to go and vacuume sealed using my food bag vacuume packer. I use No-Toil filter and oil. The pretty pink of the oiled filter looks like a dirt cake within a 2 to 3 hour ride.
This weekend I will tear it all down and inspect it all. I'll report what I find but I don't expect it will be bad.
BTW, I've read several times about how the swing arm bolt freezes up in folks' bikes. Mine is checked regualarly for just that. It slides out very easy, always looks clean, but I'll take the swingarm down too this weekend.
I am planning to take Monday off to ride, so it should be a good time to do this all. I have to change my rear bearings and seals anyway!!!!
Jerry

I'd rather be a smartass like carvr, than a dumbass like.... well, you fill in the blank!
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

Remember...HE lives in California!!

...lucky duck....

Well, for the weather, anyway! ;)

OkeyDoke. Pics are in the gallery.

specs:

Nylatron Bushing

OD .868
Length .850
ID .632

320 SS sleeve

OD .625
Length .870
ID .391+

..I take it that the '+' means more than .391 and less than .392? :wink:


All measurements in newton/meters.


...just kidding. It's thousandsths bubba!

..of an INCH!!

I still don't read any horror stories that get a freebie...........;) I'd kind'a hoped to get 1/2 dz. or so..but that didn't work out.

You guys can do better'n THAT!

BTW..Mike (the Mechanic..no, wait...the Machinist!) thought Nylatron would be a better choice than Delrin...he's worked with both. Better 'cuz of the lubricative characteristics of the black stuff.

Oh..he also has used Delrin 100AF to make gears from. Says the stuff is something like $25 an INCH in stock form. Everytime he orders some he gets the same questions: '100AF? Really?'

Really.

'Do you know what that stuff costs?'

Yup.

Another BTW....if you do this, make sure the knuckle hole has no burrs. They will skin the Nylatron. AND, if..say due to maybe your knuckle being tighter... the sleeve is too tight, do not try to remove any material from the Nylatron bushing. It will cut with machine tools, but a file or sandpaper will 'fuzz' it up (he said)...and you'll never get it cleaned up.

Oh..I say, '..if you do this...', I mean if you decide to machine your own stuff. Most of the cost was the figuring and fit-testing. If you just get the pieces made to spec, it would cost a lot less.

Keep in mind not everything is the same (duh?). No. Really!! These parts were made to fit my knuckle and my shock bolt.

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
skipro3
Gold Member
Gold Member
Posts: 4329
Joined: 11:58 pm Nov 04 2004
Country:
Location: BANNED FOR LIFE!!
Contact:

Post by skipro3 »

O.K. after reading and re-reading as well as looking at your photos, my shop manual and buykawasaki.com, I now think I understand everything you are talking about. I have a couple of questions and thoughts.
1. The "black stuff" is that graphite? That would explain the lubritive properties.
2. The press fit. How much press are you talking about here? By hand, a simple lever operated bench type press, a C-clamp, etc?
3. Crush fit. At .007 clearance on the sleeve to bushing, I would think that thing would just be falling into place. Could you explain "crush fit" please?
4. Are you going to use any lubrication between the sleeve and bushing?
5. Are you going to use any lubrication between bolt and sleeve?
6. Are you going to use the stock bolt or perhaps change to a stainless bolt to match the sleeve material?
7. Instead of a thin metal washer to protect the sleeve / bushing seam, what about a gasket or washer out of rubber, vinyl, hard plastic or the same stock the bushing is made of? Should you use a stiff type of material like stainless or soft like brass if you use a thin metal washer? Perhaps sealing it with wax or parrafin, before setting your washer in place.
P.S. I couldn't wait until this weekend. I pulled my lower suspension apart moments ago. It all looks just fine!!! Whew! You had me worried there for a bit.
Thanks for a great thread by the way. This is fun!
Jerry

I'd rather be a smartass like carvr, than a dumbass like.... well, you fill in the blank!
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

JasonWho wrote: canyncarvr, how many thousands of miles per week do you ride? You get the Iron Butt award!
The "Iron Sack" Award maybe..... :lol:
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
User avatar
KDXGarage
KDXRider.net
KDXRider.net
Posts: 14047
Joined: 06:45 am Nov 01 2004
Country: United States of America
Location: AL, USA
Contact:

Post by KDXGarage »

I admire who will take his suspension apart late at night on a school night! YEAH!

I think the folks with stuck swingarm bolts are usually the victims of the previous owner(s) lack of maintenance.

canyncarvr, there has to be SOME reason why your bearing always wears out. That is why I asked how much you ride. Do you have a press for these bearings? Ever use wibby's arbor press?

***EDIT*** Just checked out the pictures...

WOW! That looks great! Be sure to give us an update whenever you check it.

Thanks!
Last edited by Anonymous on 11:41 am Dec 03 2004, edited 1 time in total.
User avatar
m0rie
Supporting Member I
Supporting Member I
Posts: 2220
Joined: 10:25 pm Nov 29 2004
Country:
Location: Crescent City, CA

Post by m0rie »

canyncarvr wrote:Remember...HE lives in California!!

...lucky duck....

Well, for the weather, anyway! ;)
Remember the sun always shines in California! :mrgreen:

Those pics of the bushing and sleeve sure are pretty looking, hope they work as good as they look. But judging from your experiences with them _any_ improvement will be a good thing.

No hard luck story here, I just replaced it in April and its still holding up.

-Maurice
1989 KDX 200
2007 TTR-50E
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

skipro3 wrote:O.K. after reading and re-reading as well as looking at your photos, my shop manual and buykawasaki.com, I now think I understand everything you are talking about. I have a couple of questions and thoughts.
1. The "black stuff" is that graphite? That would explain the lubritive properties.
*****
No. It's Nylarod...a link to the properties of which is listed above. It is molybdenum impregnated nylon.
*****
2. The press fit. How much press are you talking about here? By hand, a simple lever operated bench type press, a C-clamp, etc?
*****
A simple lever operated bench type press will do fine.
*****
3. Crush fit. At .007 clearance on the sleeve to bushing, I would think that thing would just be falling into place. Could you explain "crush fit" please?
****
'Crush' fit in this case meaning: The inside diameter the Nylarod needs to be machined to such that when fit to the Unitrack knuckle it 'crushes' to a proper fit with the sleeve.

OK? The bushing ID starts .007" bigger than the OD of the sleeve (+/-)..when the bushing is squished into the knuckle its ID decreases. Metal does the same thing, but not to such an extent.
****
4. Are you going to use any lubrication between the sleeve and bushing?
5. Are you going to use any lubrication between bolt and sleeve?
******
Yes. As noted. Permatex Anti-seize. Hey...I thought you read what I wrote! ;) Honestly...not to be smart about it...but is what I write so convoluted that it makes so little sense? Maybe I need another martini.
*****
6. Are you going to use the stock bolt or perhaps change to a stainless bolt to match the sleeve material?
*******
I am going to use the stock bolt. For whatever reason (I don't know what it's made of) it seems to have held up pretty well.

****NOTE**** If you use a bolt other than oem make sure the threads are the same 'depth'. Another couple of turns with a die and the bolt would be squeezing the shock fork too much. The shock fork is NOT squeezed against the grease seals when assembled. It just sits there..the bolt being tightened against the end of its threads.

*****
7. Instead of a thin metal washer to protect the sleeve / bushing seam, what about a gasket or washer out of rubber, vinyl, hard plastic or the same stock the bushing is made of? Should you use a stiff type of material like stainless or soft like brass if you use a thin metal washer? Perhaps sealing it with wax or parrafin, before setting your washer in place.
*****
I've got .015" between the shock fork (I'm referring to the bottom shock assy.) and the knuckle with this bushing/sleeve combo. I don't know that I can get two <anything> that will be .005" thick. IF a piece of Nylarod could be cut/sliced that thin maybe it would work. I don't know how brittle it would be. I'm not that good with my pneumatic cut-off tool!

I had a nice piece of mylar in the shop I was going to fashion into my 'mudflap.' Of course...I can't find it now......


....Being 'organized' isn't one of my strengths.

...Come to think of it...neither is anything else! ;)
****
P.S. I couldn't wait until this weekend. I pulled my lower suspension apart moments ago. It all looks just fine!!! Whew! You had me worried there for a bit.
*******
That kind'a blows! ;) I guess Kawi never figured this joint would actually be used in any kind of dirt bike conditions.

*****
Thanks for a great thread by the way. This is fun!
Well...I'm glad you're enjoying it!

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
Post Reply