transmission output shaft

[kawagumby]

The tranny shafts are a fairly loose fit in the inner race, the bearings reside in the case, and ordinary arm strength without too much fidgeting-cussing will usually do the trick. A heavy plastic mallet/wood dowels can sometimes used to coax things apart too. The puller (and the hassle) mostly centers on the crank bearings - sometimes you'll even get that "pop" that comes from a press fit when they let loose. I use a standard 3 arm puller with some extra long bolts to get the job done. (I wish all those neat specialty tools were available back when I got started!).

Assembly is what's tricky; you dont want to force anything (or screw up the case seals) and if the crank bearings are cranky about getting back into position, you can't "feel" the assembly as well to be sure everything is lined up and going together OK. That's why I'm a fanatic about using heat ( just 200 degrees or less) and cold - to get everything together easily without something getting cocked and then binding. I want to be able to assemble the case halves without using the bolts to force them together (except for the very last umph), that way I can spin the crank as I go and make sure everything is free. A heavy plastic mallet comes in handy at this stage also, to keep every thing going together in a parallel manner in places distant from the crank bearings.

If something binds you need to take it apart and start over.

I'm no expert, but I've split a lot of cases and never had a problem. I'm sure someone out there has more info or tricks to part with.

Sometimes to get a stubborn tranny small needle bearing outer shell out of the case, I've used a dremel grinder to grind enough material out of the shell to relieve the press fit - then it'll come loose without the potential to screw up the case.

[fuzzy]

It's this step that can get you in trouble...Like you mentioned.:

http://img.photobucket.com/albums/v325/empm/m12.jpg

[crf_kdx]

Hey folks!

I found the following three YouTube clips on a bottom end rebuild.





Btw, they are produced by RMMC.

Say, fuzzy, would the tool RMMC sells for putting the case back together reduce your concern about pressing the case halves together? It strikes me one *might* have a greater feel with this tool over a hydraulic or arbor press.

[fuzzy]

YES! The socket over the output-hole trick just doesn't do it for me. I also always forget the bike cases are basically self aligning....Unlike the kart engines I'm used to dealing with.

Those vids rock!

[canyncarvr]

I probably missed it...did they show putting the alignment dowels back in the cases before reassy?

Probably. In any case (HA!...I say!!..Thass'a joke, son!!)...don't forget 'em!

Sometimes you can 'make do' if you don't have 'The Tool'. Sometimes it just ain't worth messing with it.

Thanks for the links!!

BTW...

Tusk case splitter from RM:Part# 1177390001 $60

Tusk crank tool from RM: Part# 1177380002 $60


Haven't used one...but the pulling method certainly beats the pounding method for putting the crank in.


If RM happens to change their links, (the above clicks don't get you there), you can put the PN in the search field.

No recommendation or guarantee inferred or implied, just a place to look at 'em. Your results may vary. You have specific legal rights which vary from state to state. Pictures are representative, actual product may vary in appearance but will be suitable for advertised use...if you have the sense to know that use is. Smiles all 'round.

[crf_kdx]

Okay - I finally got around to replacing the output shaft on my ride this week. The engine is sitting on my bench with the bottom half back together. (Well, maybe!) I'm sitting in the ole hot tub after dinking around on the beast for about 6 hours tonight thinking back over what I"ve done and panick sets in.

Check out the URL

http://www.motosport.com/offroad/oem.ph ... upId=20692

The two o-rings numbered 92055 in the picture - I'm positive one goes outside the case between the between the collar and the case. What I don't know is about the second o-ring . . . I'm now wondering if it went on the shaft last prior to putting on the left case. Unfortunately, the output shaft can be moved back and forth some . . . about the thickness of the bloody o-ring. I took pictures as I pulled off the case and I don't see the o-ring on the shaft but it's possible I removed it after I took off the case and before I took pictures.

Does anyone have recall of whether the o-rings go on either side of the case? If so, is it possible to just remove the left side case to install the o-ring without tearing down the right side?

Can someone check to see if their CS has any side-to-side movement for me? If so, maybe the o-rings both go on the outside of the case!

(**(&^&(*%*&$&#$ I hate it when this stuff happens!!

[crf_kdx]

Argh - I think I've answered my own question. I went back and looked through my photos and found




It seem really unlikely to me that that o-ring could have been outside the case on the CS. It seems like the bearing wouldn't have rolled over the o-ring. I think I've gotta remove the left case to install the o-ring between the shaft and the bearing. I'd understand a thrust washer there but an o-ring?!?! Sigh . . . I hate being stupid!!

Stop me if you all think I"m wrong!!!!!

[canyncarvr]

Whoa! Hold the phone.

I do NOT have any recall of (not having mine apart) or personal experience from another's KDX...BUT...

The diagram clearly shows the o-rings together. They don't fit past the collar machined into 13128. They clearly do not go outside the case.

Re: 'If so, is it possible to just remove the left side case to install the o-ring without tearing down the right side?'

Seems plainly so from the diagram.

Why two o-rings together? I asked to my mechanic BIL about it (he just walked in bragging about his new Versys..), he didn't think it was odd at all, had seen such a configuration before. One ring acts as a cushion, the other is more the seal part.

Re: 'I'm positive one goes outside the case between the between the collar and the case.'

Not from the diagram...and I doubt it.

[Jeb]

I found the answer, in pictures, in the online manual under "Output Shaft Seal Replacement" . . .

Remove the output shaft seal, shaft collar and two O-rings. Inspect all mating surfaces for damage. Replace these items as needed.


Clean and lightly lubricate all parts prior to assembly. Install the first O-ring onto the output shaft so it rests against the bearing as shown.


Install the second O-ring.


Make sure the O-ring does not become twisted - a light coat of engine oil will help it slide on easier. This can help avoid damage from the sharp ridges on the output shaft as well.


Lightly lubricate the inside of the seal with engine oil

[MX500]

Was your sprocket torqued down? Actually... It looks like these KDX's use a circlip to hold the sprocket on? That is probably half of the cause. If the sprocket was tight, it would have held in one spot and not been shock loaded and pounded into that shape.


Just my $.02 for what could have helped cause that issue.

[crf_kdx]

Thanks all. The critter is all back together. I'd love to fire it up and take her for a spin to test her out but I'd like to stay on good terms with my neighbors (it's 12:40am here)!! Jim: I greatly appreciate you taking the time to chase down the info in the online manual. Clearly, at my skill level the owners manual is insufficient and I gotta subscribe to the repair manual.

Btw, I'm still clueless as to just what caused this in the first place and I'd say anything is possible!

Again, I greatly appreciate everyone's input here!!

[canyncarvr]

The OEM trans diagram shows the orings together, then the collar, then the seal.

The OEM CASE diagram shows the bearing..but no indication where it fits with the other parts.

..so much for the obvious (and also obviously, from looking at the trans diagram, I had it all wrong).

The online manual showing how they fit (all OUTside the bearing) sure is nice!

Thanks Jeb!

But...they kind'a left out the collar, 'eh?

Or...is there a pic in the sequence missing?

crf: So, it's back together...but did you split the case again to get the oring off the shaft INside the bearing as your pic showed?

Thanks for the learnin'!!

[Jeb]

>|QBB<[/url]

But...they kind'a left out the collar, 'eh?

Or...is there a pic in the sequence missing?

I didn't include all of the pics, intending only to show where the o-rings went. But it woulda' been nice to see this TOO!

After the seal is seated uniformly and driven in place, the collar is installed with the "internal ridge" towards the engine . . .

[crf_kdx]

Well, truth be told, I had the engine back in the frame and virtually all buttoned up when Jeb's post came through; My heart sank at that point as I had an o-ring on either side of the case because that just seemed right to me. I had removed ONE o-ring from behind the collar BEFORE splitting the case and so I was positive one went outside and I didn't see a second o-ring at that point. I just didn't see how it made sense for both o-rings to be outside between the bearing and collar. Go figure.

So, it's late Friday night and I'm suppose to run a two-man hare scramble with my son on Sunday - what do I do?!!? Curiousity prompted me to measure one of the old o-rings and it's less than 1mm in diameter. Hmmmm . . . I decided I had three choices - tear the girl down again and do it right (but that probably meant sitting out the hare scramble), run with two o-rings - one inside, one outside, or try running three o-rings - one inside & two outside. So, I removed the chain, sprocket and put a second (old) o-ring outside the case and I'll be damned if the sprocket didn't go back on with THREE (compressed?!) o-rings. Recall - I was also uneasy in an earlier post about all the side-to-side play in the shaft before I split the case a second time to put one o-ring inside. I put about 15 miles on it this afternoon dinking around on country roads going up and down through the gears. Not only did it shift fine but the shifts felt more solid (less slop?? my imagination??). In the short run I'm going to run with three o-rings and hope-hope-hope that the shaft naturally had enough slop to not cause me any "alignment" woes with that inside o-ring. I'm secretly hoping the shaft eats the inner o-ring and I find pieces of it in my oil . . . but when that doesn't happen I'll probably have to pull the engine and do that dance another time since I didn't do it right the first time. Sigh. To be honest, I really don't mind the work . . . but the wife unit probably has a limit on just how much time I can spend in the garage and my son Austin is pretty keen on running our hare scramble schedule.

This has been a real education for me!

[Jeb]

Darn, wish I'd had looked up the oring pics earlier . . . I don't suppose the o-ring pieces could cause damage if they did end up floating around in the gearbox.

Good luck on your harescramble . . . it's the two man race, right? I'm GOING to race a few this year with you guys, it just hasn't worked out thus far. Tryin' to get Rick to come as well but he works Sundays

[Rick]

One of these days Jim!

[kawagumby]

I wouldn't worry about the unnecessary internal o-ring. Chances are it will just sit there till the bike is sold or rebuilt. The output shaft/output bearing position relationship is not all that critical IMO, based on my experiences rebuilding many of these things. If the case halves mated up tightly without having the assembly bolts cranked down to pull them together, that kind of speaks for itself. BTW, I've run a single O-ring without any oil leaking, but I tend to use whatever is laying around the shop so maybe my el cheapo Harbor Freight O-ring kit has fatter rings. Most bikes I've owned use one O-ring at the output shaft.

[canyncarvr]

I'm not being persnickity...I am wanting a correct picture of what's happened and how it should be. I'd appreciate your patience...

Re: 'So, I removed the chain, sprocket and put a second (old) o-ring outside the case..'


The 'outside the case' phrase doesn't gibe in my head with what I think I know about this. Considering Jeb's photos, all of it (orings, seal, and collar) are 'outside the case' from the standpoint of being able to get to them/replace them without splitting the cases. Saying one 'inside' and one 'outside' in this case refers to which side of the collar they're on? Do I understand your meaning correctly?

Re: 'before I split the case a second time to put one o-ring inside.'

From Jeb's input based on the online manual..there is no splitting necessary for orings, collar or seal. So....I'm presuming split #2 was done before those pics were posted. Right?

It's easy to see how it works after someone TELLS me how it works, but the flange on the output shaft is pretty clear. At this point (everything is easy when you know how to do it) it's clear that both orings, the collar, and the seal can be removed and replaced from the outside.

If the goal is replacement, I would think you could remove the collar and be able to retrieve the 'inside' (against the shaft flange..'inside' the collar) rings without too much trouble. A mechanics scribe should work for that...or some small tweezers. Once the collar is off there should be a good bit of working room to do that. Certainly adding one would be easy to do.

Re: 'internal ridge toward the engine'

Not sure from the pic...is there a relief in the collar that the orings fit into? I wouldn't call a 'relief' a 'ridge'..and I think I see such a relief in the pic.

Again...sorry if this is beating the proverbial dead horse. The pics are clear to me as far as how it fits..but when the trouble is gone to to take the sprocket off to put a seal on the 'outside' of the collar..I just don't get why the collar wasn't slipped out and it all put together to spec while it was accessible.

FTR..those splines do get an edge to 'em. The online manual cautions against twisting the oring when placing it on the shaft..but I'd be putting a bit of tape on the shaft before I tried to slip the orings on. At 1mm in thickness, it's going to take nothing in the way of a nick to ruin one of 'em.


A learning experience indeed! Thanks for the writeup, crf...and thank you Jeb for the first and second picture posts from the manual.


Up to now, I have assumed (there's that word...) the online manual to be a rendition of the OEM manual. From the pics Jeb posted, it obviously isn't just that. Guess I wasn't paying attention when The Moderator was champeening the cause...........

Learning things is good!!

[Indawoods]

I tried to tell ya'll that CC!

http://kdxrider.net/forums/viewtopic.php?t=3067

[canyncarvr]

But...but....I don't recall you saying there were facts and figures and diagrams and twenty seven 8x10" color glossy pictures with circles and arrows and a paragraph on the back of each one.



You CAN get anything you want.....