85 250sx rear rebuild

[fastfrontier17]

The rear on m 250sx locked up before it was put away and now I'm looking into either rebuilding it or replacing it all together...The previous owner never maintained it from the looks of it and when I open up the drain bolt nothing came out....I still can't get the drive shaft disconnected from the rear however, ran out of time to mess with it over the weekend and still can't figure out how to get it off...

anyways...at this point without cracking it open I wanna say the bearings are completely seized up and since oem bearings are so much I'm wondering if any of you guys have gone through local bearing suppliers that have matched up the originals for you and how much it all cost?

[dougspcs]

Ebay for the bearing and seal kit. Get your differential kit and axle bearing kit both..since it's all coming apart.

Now the bad part..is the crown and pinion trashed..if it is. Find a replacement rear end..look in the fill hole with a flashlight and visual the condition of the crown gear. If it is a scored mess..forget it.

If it's decent..get the manual from the site here and start tearing it down. You should be able to get the differential out and split with standard hand tools(impact would be really handy). This will be the moment of truth. If the gears are good then start popping the bearings and seals.

You will need the special tool to remove the pinion bearing retainer ring!! $70 on ebay..or take it to the dealer.

It's a lot of work, but these differentials are getting hard to find!! Good luck..

[fastfrontier17]

haven't people made the tool before? how much would the dealer charge? reason being is i have other projects and i don't wanna put too much money in this one...

...but when i felt around in there with my finger last week it felt pretty good, but once i manage to get the drive shaft disconnected i'll be able to visually inspect it...

thanks for the help!

[fastfrontier17]

with the bearing housings bolted up to the rear end the axle wasn't turning....unbolted and it would move the whole housing when you turned the axle

[dougspcs]

haven't people made the tool before? how much would the dealer charge? reason being is i have other projects and i don't wanna put too much money in this one...

...but when i felt around in there with my finger last week it felt pretty good, but once i manage to get the drive shaft disconnected i'll be able to visually inspect it...

thanks for the help!

Some say they have made the tool, but to spend a couple hours fabbing something was unproductive for me..now I have the right tool and could do it again to my other machines or someone elses..

Spend what it takes to get the job done right..save a buck here and there and it will do you no good. Just fail again!! Fix it right, it lasts forever.

Hey Ship it here..I'll do it for a fee of course!! ;)

Anyway, I like the hands on so I didn't even call the dealership..how much would depend on what you had done 1st I guess. Differential pulled and ready to rebuild..2 hours labour?? Still in the trike..4 hours?? @ $50-70/hour..do the math. Worth the tool to me.

Plus I am a very anal guy when it comes to this..CLEAN, CLEAN, CLEAN. Shop guys paid flatrate aren't gonna do what I do!!

A bit of time and effort and mine is perfect..last forever since I will change the oil unlike the lunkhead that owned it before me..

[fastfrontier17]

you seem pretty knowledgeable...another quick question...when I was cleaning the carb I tried to remove the pilot screw before I soaked the entire assembly and the head of the screw broke off in place...I didn't have a replacement and I didn't want to break any of the other jets so I left them on (took off the main jet however) and let it soak in a 1 gallon can of carb cleaning solution I've used with great success in the past... cleaned the carb very nicely...let it dry...put it back together...re-installed it on the bike...washed the gas tank out with water...disassembled the petcock and cleaned it with carb cleaner...installed some fresh gas...cleaned the air filter...installed a new plug...sprayed some starting fluid on the filter...cranked up on the 2nd kick...puttered for a second and then revved to redline on its own so I shut it off...

first thing I did was check that the throttle was moving up and down and not hung up... one thing I noticed was that the throttle appeared to not be seating on the idle screw and would not come up high enough to reach the little plate next to the throttle cable...so not sure whats going on there...so i removed the throttle cable and closed the throttle all the way down...moved it up just a little bit with the idle screw...started it up and it puttered for a few seconds and then revved to red line (without the throttle moving) popped a few times and shut off... if there is an air leak I'm not sure where it could be... any ideas?

[Jason125m]

Hey Ship it here..I'll do it for a fee of course!! ;)



Will be keeping this in mind if mine ever goes. I change the oil every ride... Hopefully it never does! I HATE messing with diffs. My one weakness. LOL

[dougspcs]

Will be keeping this in mind if mine ever goes. I change the oil every ride... Hopefully it never does! I HATE messing with diffs. My one weakness. LOL

Now I've conquered that challenge I wouldn't mind doing another..with the right tools it's easy.

[dougspcs]

you seem pretty knowledgeable...another quick question...when I was cleaning the carb I tried to remove the pilot screw before I soaked the entire assembly and the head of the screw broke off in place...I didn't have a replacement and I didn't want to break any of the other jets so I left them on (took off the main jet however) and let it soak in a 1 gallon can of carb cleaning solution I've used with great success in the past... cleaned the carb very nicely...let it dry...put it back together...re-installed it on the bike...washed the gas tank out with water...disassembled the petcock and cleaned it with carb cleaner...installed some fresh gas...cleaned the air filter...installed a new plug...sprayed some starting fluid on the filter...cranked up on the 2nd kick...puttered for a second and then revved to redline on its own so I shut it off...

first thing I did was check that the throttle was moving up and down and not hung up... one thing I noticed was that the throttle appeared to not be seating on the idle screw and would not come up high enough to reach the little plate next to the throttle cable...so not sure whats going on there...so i removed the throttle cable and closed the throttle all the way down...moved it up just a little bit with the idle screw...started it up and it puttered for a few seconds and then revved to red line (without the throttle moving) popped a few times and shut off... if there is an air leak I'm not sure where it could be... any ideas?

All I could say it that is sounds like your were pretty thorough, but everyone misses stuff once in a while.

Is the carb seated into the boot? Choke plunger in properly and seating..air can leak thru there also. If so then I guess pull it back out and triple check what you have done. Something is hanging up somewhere..

The idle mixture screw being broken isn't the end of the world provided you mean that just the brass tip of the adjuster broke..the jet is siezed in the hole I'm guessing.

Make sure when it's apart you use compressed air to really push out any small grit or gum..