250sx output shaft - OOPS

[rallyhard]

Hello all!
I've been visiting the site for a long time, but haven't posted until now.
I appreciate all the help you guys give so unselfishly.

I recently picked up a well-worn '85 250sx that needs a fair amount of work, but it runs pretty good and was rideable. The main problem is the swingarm pivot bearings were shot.

I did a little bit of research and ordered up the All Balls bearing kit, which should be here tomorrow.

Here comes the OOPS part. I didn't read enough of you guys' posts here to know that you're not supposed to, and I pulled the output shaft out of the engine while I was trying to get the left swingarm bearing free.

Now I absolutely have to "split the case" to get it back in there, right?

I haven't attempted to split a case since I was like 13 (12 yrs ago, wow), working on a Honda 50 minibike. I ended up having to have my cousin put that thing back together.

So, does anyone have any tips or tricks on the procedure? Like the order of dis/assembly, and which half of the case the gears and stuff should be put in when assembling, that kind of thing? Is it going to REQUIRE any special tools? Should I bite the bullet and pick up a repair manual?

[hublake]

Definately get a manual. Try this webite for the manual. www.helminc.com If you order from the Honda dealer he will get it from them. They have reproduction manuals for all Honda ATCs. I did the same thing when I was rebuilding my 250sx and after finding out how much of a job it was, I took it to a local motorcycle, atv shop and the final cost was over $400.00. It involves quite a bit of labor.

[rallyhard]

Thanks for the replies!

Sounds like I'm screwed. I'll be picking up a manual and I'll keep y'all posted on the progress.

[cybrman]

You should be able to download an electronic manual... do a search here someone has a site where you can download them.
I haven't pulled one completely out like your describing but I have pulled one out partially and had a thrust washer fall off. I had to pull off the right side engine cover in order to get it back together. Do another search on 300sx there was a post a while back where someone swapped a 250sx output shaft into a trx300 motor and they had some good tips for resolving the issue. It sure looks like a lot of work but it can be done.

[rallyhard]

YES! Thank you for the recommendation, cybrman! I searched the forums and found this thread, ttp://www.3wheelerworldforums.com/showthread.php?t=56218&highlight=service+manuals, which has a link to downloadable manuals for quite a few wheelers, including mine

My All Balls bearings just arrived, and I'm impressed.
For 27.80, I got the two tapered roller bearings, seals, and the tin plugs that you knock out when you go to drive out the old outer races.
For 6.45, I got front bearings for my Tri-Moto 125, which I added to the order after I'd placed it, via email.
And 4.95 for shipping.

I'd probably be riding by now if I hadn't pulled that shaft out.

OK, time to study my shiny new downloaded service manual!

[Dirtcrasher]

I have fixed 2 of these without splitting the cases. If you remove the clutch cover and the kickstarter assembly, you can get in there....

The gears that fall out are a piece of cake to get back in right, the problem is the thrust washer next to 1st gear that falls out and into the case. That will have to be retrieved and put back in place.

Get a manual, get the washer in place, get the gears in right and then slide the shaft back in while rotating the output splines to get it all to mesh. Some internal gear bushings have oil holes that must line up and I believe the SX tranny has one of those bushings. If you have all the pieces out of the case, then you'll see what I mean....

All hope is not lost!

[rallyhard]

Very good, sir. Your confidence is inspiring.
This is just what I needed to hear.
I'll make the attempt of getting everything back on the shaft without splitting case and let y'all know how it goes!

[Dirtcrasher]

After you find all the goodies and figure out how they go together.....

Lay it on it's right side and get the motor as flat as you can. Put each gear and bushing in place, use grease to hold them in position if they move around. Don't overlook the "dreaded" 1st gear thrust washer as it will run and shift but you'll be missing a few thousandths of engagement and 1st gear will soon die. Then just slip in the shaft and rotate it to get it through, then you can flip the SX upright and get at the rest of it from the clutch side. I believe that output shaft also runs a kickstart idler gear and bushing (I'm running on memory here though....) Good luck!!

[rallyhard]

Good info. Thanks again!

It looks like the first/next step, in my case, would be to remove the output shaft from the driveshaft. Then I'll do the swingarm bearings and get that mounted back up so I can lay the machine over on its side easily. Next I need to pull the RH (clutch) cover, and the clutch itself (which has a LH threaded nut). After that, I might have to deal with some gears and such in there by the clutch and get them out of the way for the shaft to come through. Then I do as you said and stack up the goods from the left side, slip the shaft through, and reassemble.

EASY AS PIE

Cool, well here goes!

[rallyhard]

Well, I finally got around to finishing up the 250SX swingarm bearings/output shaft fiasco/operation.
I was able to get the shaft back in there without splitting the case.
It wasn't all that hard, really. Only 2 concerns:
1. The 1st gear washer never showed up. Hopefully, it just stayed in place.
2. A little chunk of metal that obviously broke off something did show up in the bottom of the case. I'll have to snap a pic and see if anyone can ID it.

It seems to shift all right, but the auto clutch isn't doing its thing, yet. When you pick the shift lever up into gear, it immediately lurches forward, and you can feel the clunk of each gear when you shift. I haven't gotten around to messing with the adjustment, but hopefully that's all it takes. I'm pretty sure that it was doing the same thing when I test rode it for the first time, back when it still had the shot swingarm bearings, so I'm not too concerned.

BTW, I'm in the process of buying a new swingarm and axle for the 225DX from willrideanything, so I should have some that beast back on the trail soon, too!
I'll put up pics.


Anyway, thanks again to you guys for your help!

[rallyhard]

concerns:
1. The 1st gear washer never showed up. Hopefully, it just stayed in place.
2. A little chunk of metal that obviously broke off something did show up in the bottom of the case. I'll have to snap a pic and see if anyone can ID it.

1st gear went out not long after getting the bike going again. Ran fine w/o 1st for 3.5 years, until I sold it the other day.

I'm in the process of buying a new swingarm and axle for the 225DX from willrideanything, so I should have some that beast back on the trail soon, too!
I'll put up pics.

The swingarm that I got from willrideanythin had an extra piece of metal with an o-ring on it where the rear gearbox mounts, compared to the old one. I was able to simply saw it off and file the surface flat, and it worked like a champ for the next 3.5 years, until I sold it the other day.