transmission output shaft

Got questions? We got answers....
crf_kdx
Member
Posts: 106
Joined: 08:52 pm Aug 15 2005
Country:
Location: Richmond, KY
Contact:

transmission output shaft

Post by crf_kdx »

Hey folks!

Cleaning up the bike after a ride today and I noticed that the CS sprocket had a lot of free play (not side-to-side but "rotational"). A closer look revealed that the teeth on the counter-shaft itself are wearing away. I'd conjecture maybe half of each spline is gone. I assuming there's not much I can do to save it at this point. Sigh . . . but I have a couple questions:

(1) Is this sort of wear normal for 4000 miles? If not, what might cause it? Should I run cheaper CS sprockets assuming they are made from a softer metal?? Btw, I typically run a Renthal CS sprocket.

(2) It looks like the part (13128) can be had for a bit under $100 at a couple of online merchants. When this critter gives way and I have to open up the girl, what else should I regard as a wear item and consider replacing? Btw, the top end has only about 600 miles on it.

Thanks in advance for your input!

Kirk
"There are two kinds of adventurers: those who go truly hoping to find adventure and those who go secretly hoping they won't."
~ William Trogdon

2002 Honda Shadow ACE 750
2005 KDX 200 (mine)
2006 CRF 250X (son's)

2004 TTR 125LE (for sale)

KORHS Series: Senior C
User avatar
Jeb
Gold Member
Gold Member
Posts: 1894
Joined: 08:01 pm Jul 14 2006
Country:
Location: Cincinnati / Northern Kentucky

Post by Jeb »

If I understand you correctly you'll be replacing the shaft, requiring splitting the cases. (?)

Since the play is rotational and 1/2 the spline is gone I'm assuming what's missing is the thickness of the teeth as viewed from the side. 'Sounds bizarre. I'm trying to imagine what would cause that kind of wear (it doesn't make sense). I've heard that having one's chain too tight can cause premature wear, perhaps this is an example. (I don't know that to be the case, someone else chime in please).

Can you take a digital picture and post it this evening?
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

CLICK FOR PICS!
crf_kdx
Member
Posts: 106
Joined: 08:52 pm Aug 15 2005
Country:
Location: Richmond, KY
Contact:

Post by crf_kdx »

I'll post a picture soon . . . it is strange indeed.
"There are two kinds of adventurers: those who go truly hoping to find adventure and those who go secretly hoping they won't."
~ William Trogdon

2002 Honda Shadow ACE 750
2005 KDX 200 (mine)
2006 CRF 250X (son's)

2004 TTR 125LE (for sale)

KORHS Series: Senior C
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 »

I've run some junk CSS that were loose to start with..and there was no wear on the splines.

I generally run Renthal CSSs, 'cuz they fit better..last longer...still no wear on the shaft.

I've not heard of that as a common complaint. I have heard of guys welding their sprockets on the shaft as a 'last ditch' effort at getting in some more riding time before having to fix it.

I can't imagine that went well..there being a seal close by and all that...but it's been done.

I'd have to hope it was a less than stellar quality shaft that the 'not normal' part. That doesn't give you thrills and chills at the prospect of NOT getting another one, I s'pose.

CSS are cheap. One that IS cheep isn't going to do the rest of the sub-assembly (final drive) any good.

You question is valid..run cheap or not. While I've not heard anything of the sort being 'normal', neither do I know of a reason to not use Renthal CSS.

Comes down to your choice.

Good luck!

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

bike profile: !clicky!
User avatar
kawagumby
Gold Member
Gold Member
Posts: 927
Joined: 10:09 am Nov 30 2006
Country:
Location: California

Post by kawagumby »

Might have been a part that didn't get quite the heat treatment it was supposed to - that happens sometimes on any kind of machinery. In any case (no pun intended), I'd certainly change the bearing while I was at it since that bearing takes a lot of abuse also.

Like Jeb allluded to, and you probably know this already, make sure you're running the right amount of chain slack, more so if you ride in a lot of mud.
1994 KDX200, Beta 200rr, yz125, yz250, kx100 modded for adult, gasgas contact 250.
crf_kdx
Member
Posts: 106
Joined: 08:52 pm Aug 15 2005
Country:
Location: Richmond, KY
Contact:

Post by crf_kdx »

I finally got around to taking a picture tonight . . . any thoughts?

[img::]http://kdxrider.net/media/albums/album136/splines.jpg[/img]
"There are two kinds of adventurers: those who go truly hoping to find adventure and those who go secretly hoping they won't."
~ William Trogdon

2002 Honda Shadow ACE 750
2005 KDX 200 (mine)
2006 CRF 250X (son's)

2004 TTR 125LE (for sale)

KORHS Series: Senior C
User avatar
Jeb
Gold Member
Gold Member
Posts: 1894
Joined: 08:01 pm Jul 14 2006
Country:
Location: Cincinnati / Northern Kentucky

Post by Jeb »

WOW!! Gosh Kirk, that almost looks machined! I'd say that's unusual wear. I wonder if the previous owner had a sprocket on it that had a poor fit, one with large gaps between the sprocket splines.

'Certainly no getting around eventual replacement. If and when you do it call us fellow Kentuckians; maybe we can make a road trip, help you get it fixed, then go riding the next day at MPOR or somewhere.

You probably already know this but it should look more like this:

[img::]http://kdxrider.net/media/albums/album66/cs_shaft.jpg[/img]
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

CLICK FOR PICS!
crf_kdx
Member
Posts: 106
Joined: 08:52 pm Aug 15 2005
Country:
Location: Richmond, KY
Contact:

Post by crf_kdx »

It *is* amazing how "clean" the wear is on the shaft. I can't blame this woe on a previous owner as I bought the bike new. Sigh . . . I initially used RMMC house brand sprockets but I've been using Renthal CSS for quite some time now. Chain care (cleaning, adjustment and such) is part of my after ride bike routine. The notion of an insufficient heat treatment makes sense to me . . . especially since other options place blame somewhat on my shoulders! :-)
"There are two kinds of adventurers: those who go truly hoping to find adventure and those who go secretly hoping they won't."
~ William Trogdon

2002 Honda Shadow ACE 750
2005 KDX 200 (mine)
2006 CRF 250X (son's)

2004 TTR 125LE (for sale)

KORHS Series: Senior C
User avatar
scheckaet
KDXRider.net
KDXRider.net
Posts: 3740
Joined: 12:09 am Nov 10 2005
Country:
Location: edmond oklahoma

Post by scheckaet »

it's just weird how the wear looks so even and clean. Is it the same everywhere???
crf_kdx
Member
Posts: 106
Joined: 08:52 pm Aug 15 2005
Country:
Location: Richmond, KY
Contact:

Post by crf_kdx »

Yes, the wear is uniform / consistent around the shaft. And it is very strange!!
"There are two kinds of adventurers: those who go truly hoping to find adventure and those who go secretly hoping they won't."
~ William Trogdon

2002 Honda Shadow ACE 750
2005 KDX 200 (mine)
2006 CRF 250X (son's)

2004 TTR 125LE (for sale)

KORHS Series: Senior C
User avatar
scheckaet
KDXRider.net
KDXRider.net
Posts: 3740
Joined: 12:09 am Nov 10 2005
Country:
Location: edmond oklahoma

Post by scheckaet »

almost looked machined or sumthin, the edges look sharper than I would expect if it was due to sprocket wear from too much free play.
Damned gremlins!
crf_kdx
Member
Posts: 106
Joined: 08:52 pm Aug 15 2005
Country:
Location: Richmond, KY
Contact:

Post by crf_kdx »

I started to read the service manual and I began looking at the Kawi "microfiche" tonight to see what I in for when this shaft goes. ((I wish I knew how long it would last as the first two HS of the year here in KY are April 20th & May 4th. Not that I'm any good but it's a boatload of fun even finishing near the bottom.)) Anyway, I found a couple links at ThumperTalk with pictures showing the case splitting process and I thought I'd share them here:

http://www.thumpertalk.com/forum/showth ... t=no1clyde

http://www.thumpertalk.com/forum/showth ... t=no1clyde

I'm going to try to get the parts here so when she goes belly up on me I'll have everything ready for replacing the shaft. I'll post my best guess for a parts list within a day or so to let you folks weigh in on it . . . overkill, underkill, hey stupid - you can't tell what's bad 'til you tear it apart. I do plan on keeping the KDX for the long haul and so I don't mind a bit of overkill if it buys me something down the road.
"There are two kinds of adventurers: those who go truly hoping to find adventure and those who go secretly hoping they won't."
~ William Trogdon

2002 Honda Shadow ACE 750
2005 KDX 200 (mine)
2006 CRF 250X (son's)

2004 TTR 125LE (for sale)

KORHS Series: Senior C
User avatar
Jeb
Gold Member
Gold Member
Posts: 1894
Joined: 08:01 pm Jul 14 2006
Country:
Location: Cincinnati / Northern Kentucky

Post by Jeb »

Kirk - how well does the service manual illustrate splitting the cases and getting to this shaft? If you're uneasy about the info you have, the online manual provides a decent description and pretty good pictures. PM me to learn more . . .

rockymountainmc.com sells a case splitter for a decent price:

http://www.rockymountainmc.com/productD ... lyId=17167

better yet, consider contacting a local shop to rent it.

You probably already have this on your impending list but if not include piston rings and a complete gasket set.

'Hope she holds out for the next few races. I'll be joining you June 8 in Boiling Springs, possibly in Millerstown
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

CLICK FOR PICS!
User avatar
fuzzy
KDXRider.net
KDXRider.net
Posts: 3437
Joined: 01:29 pm Jun 18 2003
Country:
Location: Fredneck, MD

Post by fuzzy »

You can spit the cases, and take it apart easilt enough. Good luck getting it back together, and having the bottom end be reliable. Might as well just go ahead and have the bottom end done...Replacing the output shaft while your at it....Or live with it until it's an absolute necessity.
'91 KDX 200 Project $300 KDX
'95 KDX 200 Project $600 KDX
'94 WR 250 Always a project
crf_kdx
Member
Posts: 106
Joined: 08:52 pm Aug 15 2005
Country:
Location: Richmond, KY
Contact:

Post by crf_kdx »

Oh, my plan is to ride it 'til the output shaft craps out or nearly craps out before I split the cases. Curious, fuzzy, in your mind what does "have the bottom end done" mean?
"There are two kinds of adventurers: those who go truly hoping to find adventure and those who go secretly hoping they won't."
~ William Trogdon

2002 Honda Shadow ACE 750
2005 KDX 200 (mine)
2006 CRF 250X (son's)

2004 TTR 125LE (for sale)

KORHS Series: Senior C
User avatar
fuzzy
KDXRider.net
KDXRider.net
Posts: 3437
Joined: 01:29 pm Jun 18 2003
Country:
Location: Fredneck, MD

Post by fuzzy »

Bottom end rebuild. New crank bearings, have crank checked and rebuilt if necessary. And....obviousely have the output shaft replaced. A 2-stroke bottom end is not like a 4-stroke 'block.' The cases/crank must be aligned (w/ gauges) during assembly as opposed to being able to bolt in a crank/new bearings on a 4-stroke.
'91 KDX 200 Project $300 KDX
'95 KDX 200 Project $600 KDX
'94 WR 250 Always a project
User avatar
kawagumby
Gold Member
Gold Member
Posts: 927
Joined: 10:09 am Nov 30 2006
Country:
Location: California

Post by kawagumby »

For what it's worth, the lower rod bearing is usually very durable and if the bike is not an extremely high-time unit, you could just limit the work to replacing the crank seals and the output shaft and bearing. I've gotten over 500 hours on a KDX lower end before either selling or rebuilding.
1994 KDX200, Beta 200rr, yz125, yz250, kx100 modded for adult, gasgas contact 250.
crf_kdx
Member
Posts: 106
Joined: 08:52 pm Aug 15 2005
Country:
Location: Richmond, KY
Contact:

Post by crf_kdx »

It looks like I can replace all the bearings, seals, bushings, c-clips and such for a bit over $225. Btw, Service Honda seems to have a price on OEM parts that beats MSRP, MotoSport, Ron Ayers, et al. If I'm going to split the cases . . . I might as well take care of what I can while I'm in there. Like I said above, I plan to keep this bike for the long haul. The bike has about 4k miles on it . . . likely well under the 500 hours mentioned by kawagumby. From the reading I've done it sounds like a (cheap) press might be in order here too. Harbor Freight has a 6 ton press for about $80.
"There are two kinds of adventurers: those who go truly hoping to find adventure and those who go secretly hoping they won't."
~ William Trogdon

2002 Honda Shadow ACE 750
2005 KDX 200 (mine)
2006 CRF 250X (son's)

2004 TTR 125LE (for sale)

KORHS Series: Senior C
User avatar
kawagumby
Gold Member
Gold Member
Posts: 927
Joined: 10:09 am Nov 30 2006
Country:
Location: California

Post by kawagumby »

That's the ticket...I built my own press and used it for motorcycle work so much it paid for itself many times over. Also look for pullers to disassemble the case halves and those that will pull the bearings off of shafts. Flat bearing removal tools that fit behind the bearing so that you can grab and pull with the puller are great to have too. Don't be afraid to heat the cases and freeze the bearings/crank before reassembling, that really helps avoid problems that come from forcing.

Be sure to check out the tranny end shaft bearings. The only bearings that ever failed on my KDX's were the smallest tranny bearings that reside in the case. Believe it or not, the latest crop of KDX's still used the same bottom end and tranny (with only minor revision) that was used in the air cooled models. A great, bullet-proof design.
1994 KDX200, Beta 200rr, yz125, yz250, kx100 modded for adult, gasgas contact 250.
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 »

Interesting to see pics using a harmonic balancer puller. I've never split a case..never seen it done.

I figured there would need to be pressure applied in the transmission area, too. Is it generally, always, or sometimes true that pressure applied only at the crank will do the job?

Simply tapping the trans end is enough to loosen the transmission shaft bearings?

Seems a lot to expect considering the number of shafts on that end.


Some pics similar to the ones noted above would be a great reference for the rest of us that will get to do that sooner or later...


hint hint hint...

Good luck!!

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

bike profile: !clicky!
Post Reply