splitting the cases on 00 426

3 replies to this topic
  • okieonayamaha

Posted April 28, 2004 - 05:14 PM


I have already torn the top end down on my 00 426. Now I need to know what specialty tools if any I might need to split the cases and if it is even possible to do on your own at home. The reason is we believe that either a rod bearing is out or a crankshaft bearing so we are just going to replace them all. We shouldn't have to mess with any of the sprockets for the gears should we? Just want to pull the crankshaft out and replace the bearings. Any advice would be appreciated and if there is something else I have to do and someone knows please let me know because this is a first for me. thanx

  • TonyDeCoster

Posted April 29, 2004 - 07:30 AM


Are you flying without a net ( service manual)? :thumbsup:

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  • SXP

Posted April 29, 2004 - 09:35 AM


Click on my name on the left, then click on "show all user posts" then go my earlier posts in the Feb/March 04 time frame. There is a lot of Q&A info on this very subject from a bunch of TTers.

Also, here is info I received via PM when I went through the same process. I hope the respective TTers don't mind my posting it on the board

From Mad_Potter:

OK, first off, you MUST have the manual. Follow it and you shouldn't have any problems.
Tools you must have, torque wrench, circlip pliers, flywheel puller, an impact wrench will help with removing certain nuts, T-30 bit ( I think) for removing the stator. And since you are removing the crank, you'll need a puller for that.
If you have a digital camera take pictures of the wire and hose routing as you remove the tank, radiators etc otherwise you'll be pulling your hair out trying to remember where things went. You are replacing the rod which is a little more complicated than what I did. I was able to leave the crank, rod, piston assembly attached to the left case since I was only replacing gears in the tranny. You won't have to take the gears off the shafts, just take the gear, shaft assembly out of the cases. I laid out paper towels on my bench and as I removed parts I would lay them in order and also write what the part was and the page number in the manual next to it to help me remember what things were. It is a lot of work and there is a lot of going back and forth from one section of the manual to another but it's not that hard. Just follow the manual!
Good luck!

From Henrik:

yeah, there are some things to concider. The bearings that sits right were the clutch lever is can be tricky to get out. You need some kind of puller. I used a sliding hammer (don't know what it's called really, it's a long rod with a hook attached in one end and a end stop in the other. On the rod there is also a big heavy slider that you knock against the end stop. Place the hook in th bearing and tap/knock it out. Thing is - there is not alot of room there so I suggest you ask a Yamaha mchanic if they have either the original tool meant for this OR buy the kind of dvice I described (which shoulnd't be expensive at all!). Apart from that single bearing I don't think there is any problem getting them out. In however. The enginecase is aluminium as you know. I don't think pounding on it is very good but I didn't have a press so I used this trick to get the crankbearings in. Put the bearings in the freezer or out side if it's winter and cold for like an hour. Oil up the bearing outer race and put it in the bearing seat. If you are lucky it will just slip in, if not... Tap gently all the way around the outer race of the bearing gently pushing it in. Of course, again, it is better to pess them in but this is how I did it. make SURE that the bearing is all the way in, you won't get your case together otherwise and that my frind won't be fun! MAKE ABSOLUTLEY SURE THAT THE BEARING IS PROPERLY SEATED OR YOU ARE TOAST. ok? Great!. Only apply thread lock where the manual states you should (and that isn't every bearing lock!) Never tap on the inner race of the bearing!!! NEVER!

All the other bearings are a breeze. To remove you tap on the inner race (only to remove!!!) and to get them in you tap on the outer race. Do not use moore force than you think it can take thn youwill be safe. Remember to lube up the bearings to get them to slide in - the excess oil will escape and th beraings won't just spin in the case, I promise! But it is important to lube them when putting them in or you will kill the bearing seat.

If you don't buy the bearings from your local Yammie dealer but rather from a hardware store that sells SKF (the best!) or the same brand Yammie uses (can't remeber it rightnow!) remember this:

- Double check which bearing goes where
- Some (at least one!) is a high speed bearing denoted C3 or C4 in the serial number - it is vital you get this right. An ordinary bearing can't take the RPM's but the C# will.
- Three bearings you have to buy from Yammie: 2 crank bearings and then the bearing for the PTO (the shaft where the front sprocket is attached!)

Yammie will charge twice what the hardware store will!!!!

When you change the bearings remeber to buy all the seals too (remeber the seals for the waterpump too!!). These are ordinary standard seals that you can buy at a good hardware store. Since I'm from Sweden I can't recomend any good american hardware store but you'll figure that one out on your own. Oh, when you buy seals and bearinsg - always bring the old seals and bearings with you to compare with the new ones. It's really easy to get it wrong. Also remember that some (at least one!!) bearing needs to be sealed, denoted -RS1 or -RS on the bearing number. Now here comes anothr clever thing... The bearings that are fully sealed are usually cheaper bcause theyr are moore widley used. You too can use them by simply jerking out the bearing seals there is no difference on the bearing it self, just the sealing and pricetag. The bearings that are totally sealed are denoted -2RS on the bearing number.

Oh, try to get as much thread lock out as you can. It may cause problems when you try to get the bolt in other wise and busted threads mean that you will be spending ALOT of $$ for nothing buying a new engine case. Clean everything as good as you can. Cleaning is cheap compared to fixing.

I hope I didn't scare you by all this, it really is just as simple as it sounds. Just think twice! Oh, feel fre to ask away if ther is any other issues. I check the forum at least three times a day!!!'

Best regards Henrik

Also from Henrik:

First off - I think it's wise to press the bearings in so that you see the number when you split the case. That way you instantly know what type of bearing it is and you can order them without evn taking it apart. Now, I know it doesn't matter but that's just my thought.

Yeah, knowing when the crank is in place is tricky. Even knowing when the bearing is seated correctly can be tricky. I used a bit of gut feeling. I cooled the crank down and then I put the crank on the working bench. I then took the left case half and put it on the crank and then gently tapping on the inner race while a buddy pressed on the case half I drove it on to the crank, sort of the other way around what the manual says.... But it worked. The thing is, the sound changes from the tapping when the bearing/case half is seated correctly on the crank!! Remember not to support the crank on the crank end - it will bend. And take it easy with the tapping... Oh, lube evrything up too!!

Hope this helps and good luck. It's not as difficult as it looks :thumbsup:

  • Boostn

Posted April 29, 2004 - 05:58 PM


if you have to take the crank out, I'd imagine you have to take everything apart. I am not sure, but I did have to go all the way down to replace the tranny gears but left the crank and piston on.

Definitely get the manual, couldn't do it without. Read and REREAD details to get it done right, don't skimp on anything. Lube everything.

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