Some pointers about rebuilding a 250sx diff..

[dougspcs]

I was concerned about a growl noise from the rear end of my SX..so I followed the manual and pulled the differential out..

Pretty obviously the pinion bearing is trashed..

Anyway the next step is to tear it down but it the manual says I need alot of special tools..

Any pointers on how to tear apart the differential to replace the bearings using standard hand tools would be great...

[dougspcs]

Never mind..I figured it out.

I split the case, removed the crown, bearings and seals..

Then came the pinion..there isn't any way under the sun to remove the pinion shaft without the special tool.

So off to the dealer I go tomorrow..unless one of you guys has a way to save the day??

[atc007]

Clean her all out,heat er up a little. Big cold chisel and hammer. That lock nut spins right out of there. Obviously using the gentlest touch possible. Remove your pinion,,now's where you say,,there's no way to go ahead! The inner pinion bearing is a tricky little sucker without the proper bearing puller. I dremel it old school,2 places then she comes right out w a little work. . Like a broken off female pipe. IF you have access to a dealer w the proper tools,and they don't bend you over too bad,,it's worth it! But it can be done quite easily with your shop tools. A good vise is essential throughout,you need all the hands you can use here! Good luck! There was a great how to on here by ?? A TriZ guy near Buffalo. But he has all the Honda tools : (

[atc500x]

There is an easy way to built a special tool to remove the special nut on the pinion.
Took a steel tube with a 1/4 wall thickness that fit ''tight'' in the nut,weld 2 spot on the tube and grind it,they will fit perfect in the nut,using a pipe wrench to turn the tube.....you have a special honda tool in 10 minute

[MonroeMike]

Good thread here.
http://www.3wheelerworld.com/showthread.php?92488-The-curious-case-of-Jim-s-SX-How-to-save-a-Trike

A tool Racerxxx made (same thread).

http://www.3wheelerworld.com/showthread.php?92488-The-curious-case-of-Jim-s-SX-How-to-save-a-Trike&p=708050#post708050

[dougspcs]

There is an easy way to built a special tool to remove the special nut on the pinion.
Took a steel tube with a 1/4 wall thickness that fit ''tight'' in the nut,weld 2 spot on the tube and grind it,they will fit perfect in the nut,using a pipe wrench to turn the tube.....you have a special honda tool in 10 minute

That isn't a half bad idea...wish I had a welder.

Or I found this:

http://cgi.ebay.com/ebaymotors/Honda-ATV-Pinion-Bearing-Nut-Tool-60MM-/170616494014?pt=Motors_ATV_Parts_Accessories&hash=item27b98917be

But at $70 am I ever gonna need it again..might just as well take it too the repair shop and let them do it for that much money.

[dougspcs]

I decided to do the rebuild myself so I bought the special 60mm tool from ebay..got it today and had the rest apart in 15 minutes. Pinion bearing is replaced, the little shaft support bearing is a major bltch like 'atc007' mentioned..but upon closer inspection is it completely clean and running smooth and quiet. I think I will leave it in..

Should have it back together in by tomorrow..

New exhaust, new Bear Claws all around, diff rebuilt..should be ready to go to hell and back!!

[Dirtcrasher]

Out of maybe 6 or so diffs, I find the same size shim on either side; in other words, they don't shim it.030 one way and .010 the other. They seem to be identical.

You should be fine as long as that tiny needle bearing is good and the shaft looks good. It's that big pinion bearing that flops all around..........

[dougspcs]

Out of maybe 6 or so diffs, I find the same size shim on either side; in other words, they don't shim it.030 one way and .010 the other. They seem to be identical.

You should be fine as long as that tiny needle bearing is good and the shaft looks good. It's that big pinion bearing that flops all around..........

Yeah the big bearing was f*&^ed..came apart as I was hitting it off the pinion shaft.

The shims do seem identical, but I didn't measure to be sure..but I have marked them to indicate the side they came off so I can put them the same side..just in case!!

[atc007]

REALLY check that pinion bearing!! Make SURE those needles won't fall out ,and be sure it is good! Not doubting you,,,just saying,,,ALL this work ,then have that give up 200 miles down the road.... They are usually whipped? You must have really caught her early. Actually,,I have SETS of BROKEN cases. That is where they will break,,right on the pinion bearing! But,,that is obvious stupidity.. Which,,I've seen my fair share of!

[Headsup]

Ok so i know i need the Bearing Remover to Get mine out.. Well ill start saving for it now because i hear a noise in the rear, My swingarm bearing were completely whipped out. I can imagine These.. Anyway Thanks as always, Love just reading on 3WW, Always find more information..
Also atc007 makes me not want to ride until i get them replaced.. Maybe time to strip her down for teh winter..

[dougspcs]

REALLY check that pinion bearing!! Make SURE those needles won't fall out ,and be sure it is good! Not doubting you,,,just saying,,,ALL this work ,then have that give up 200 miles down the road.... They are usually whipped? You must have really caught her early. Actually,,I have SETS of BROKEN cases. That is where they will break,,right on the pinion bearing! But,,that is obvious stupidity.. Which,,I've seen my fair share of!

I know what you're saying..I checked it REALLY well!! It's good..I will be thoroughly cleaning it tomorrow before reassembly and will double check!!

[threewheelin-feelin]

bringing up an old thread here but i need some help. i have gotten the whole thing apart. we even made the tool to get the locknut out. well now im stuck we can not figure out how to get the little needle bearing out...any suggestions?

[Flyingw]

You need a blind hole bearing puller to get it out. When installing the new bearing, since its a needle bearing you cant beat on it without destroying it. Freeze the bearing overnight. When ready, heat the case to about 250 in your wifes oven. The bearing should drop right in. be sure to heat the case for at least an hour. This method works for the ring gear bearings as well. For the pinion bearing, freeze the pinion shaft and heat the bearing. It will drop right on to the shaft then freeze the pinion shaft with the bearing on it. Heat the case to install the pinion shaft and bearing. Its a little time consuming but I use this method for hassle free bearing installation.

[atc500x]

Don't use your wife oven,I ever do it,she will kill you,hehehe
Everything she will cook in the next week will taste gear oil.Clean or not there is always oil somewhere in aluminium.


You need a blind hole bearing puller to get it out. When installing the new bearing, since its a needle bearing you cant beat on it without destroying it. Freeze the bearing overnight. When ready, heat the case to about 250 in your wifes oven. The bearing should drop right in. be sure to heat the case for at least an hour. This method works for the ring gear bearings as well. For the pinion bearing, freeze the pinion shaft and heat the bearing. It will drop right on to the shaft then freeze the pinion shaft with the bearing on it. Heat the case to install the pinion shaft and bearing. Its a little time consuming but I use this method for hassle free bearing installation.

[Flyingw]

If he was smart, he would do it when she isnt home then claim ignorance when the chicken tastes like oil. This is why I have a wall oven in my garage. An alternative is to buy a small countertop oven for less than 50 bucks.

[threewheelin-feelin]

You need a blind hole bearing puller to get it out. When installing the new bearing, since its a needle bearing you cant beat on it without destroying it. Freeze the bearing overnight. When ready, heat the case to about 250 in your wifes oven. The bearing should drop right in. be sure to heat the case for at least an hour. This method works for the ring gear bearings as well. For the pinion bearing, freeze the pinion shaft and heat the bearing. It will drop right on to the shaft then freeze the pinion shaft with the bearing on it. Heat the case to install the pinion shaft and bearing. Its a little time consuming but I use this method for hassle free bearing installation.

thats some pretty good advice. we will be working on it tomorrow night so we will see how it goes

[threewheelin-feelin]

If he was smart, he would do it when she isnt home then claim ignorance when the chicken tastes like oil. This is why I have a wall oven in my garage. An alternative is to buy a small countertop oven for less than 50 bucks.
lol how bout a map gas touch?

[Flyingw]

I have tried applying MAPP gas heat and it didn't have the same effect. Heating the entire part in the oven workes very well. I now use this method for installing most bearings. SX axle tube, front wheel hub, tranny, crank, rear carrier etc..... Most bearings stay in place with whats called an interferrance fit meaning the bearing is a CH larger than the hole. Heating the part expands the bearing hole and freezing the bearing shrinks the bearing and in most cases allows the bearing to drop in to the hole with little or no effort. All you have to do is wait till the part cools off. I was putting bearings in to a 250R case and I dropped the bearings in and flipped the case over and all the bearings fell out. This is also a great way to install timing chain gear on the crank for the 185/200 series motors.

[threewheelin-feelin]

well the bearing is in the freezer for the night. we finally got the needle bearing out after 4 nights of working with it. we ended up fracturing the case in the process. im so fed up with the rebuild i dont even care anymore so it will be getting jbweld tomorrow and everything reinstalled. i also plan on NEVER rebuilding another one....this has been over two weeks of hell

[Flyingw]

Do you need a case?

[Flyingw]

You want me to put it together with a fresh case? Send me your diff and the rebuild kit and I will return it looking like new.

[threewheelin-feelin]

ill tell you the truth between buying all my esr parts for the 250r, christmas and the bearing kit for this diff..i am about out of extra money...just curious how much would you charge for a new case if i cant fix mine

[Flyingw]

It's not about money for me. I have an extra case I'm offering up along with my services. Just cover shipping and I will take of the rest. It's Christmas time..... What can I say.

[threewheelin-feelin]

i dont think im going to have any problem putting it back together...and thank you so much for offering to put it together...but i will certainly pay shipping on the case to 23661 if you dont mind sending it...any parts you need? maybe i can send you something

[Flyingw]

Not a problem. PM me your address. I'll send it USPS flat rate so 11.20 for shipping. I'll put my return address in the box. Would you like the case powder coated? Right now its completely stripped (bead blasted). I PC my own stuff.

[userj8670]

What a gentleman you are Flyingw! Thats a real man right there.

[Flyingw]

Isn't that why we come here. To help eachother out.