Bottom end rebuild. Gears giving me fits

Split my cases on my 05 250 last night. Cleaned everything up and pulled my tranny gears out along with shift forks and drum. Now I attempted to put it back togather just to make sure I remember and now when I get both sets of gears in they seem to have a catch in it that wont let the gears make a full rotation... Im assuming gears/shift forks/shift drum have to go in at the same time? Any help/advice?

Yes, the shift drum with shift forks have to be installed at the same time. With everything installed, you should be able to "shift" the bike thru all of the gears while rotating the countershaft axle.

Did you install them in the left or right case half?  They're supposed to go in the left half.  Anyway, sometimes the shift fork shafts, the gear shafts and/or the drum rock just a bit and cause that catch you're talking about.  Either dry assemble the case halves (without the crank) to stabilize the shafts and try again, or maybe you can hold the shaft ends while rotating the countershaft with your third hand.  Either way, I'd make sure the trans rotates and shifts smoothly before installing the crank.

Edited by bg10459

Yeah I installed them in the left half. What a giant PITA. I only installed both sets of gears and there was still a catch...couldnt find anything it was catching on

YZ must be different from KX. i install the trans in the right side....it is easier to adjust the drum and set forks. I then install the idler so the trans stays in place  while  I set the crank in the right side case also......check all movement and and then install the left side case making sure everything stays lined up.

I have installed YZ250 gears both ways - into the right case and into the left case. The left case is BUNCHES easier. The manual also states that the gear clusters should be installed into the left case. You are doing that right.

Yeah I installed them in the left half. What a giant PITA. I only installed both sets of gears and there was still a catch...couldnt find anything it was catching on

It IS a giant pita, but it's best to install the drum and shift forks also.  That will hold the sliding gears in the right place.  I bet they're not in the right spots and that could be the problem.  I had this exact same issue and nothing was wrong, just things not lined up properly.

I had full intentions on not messing with the gears and just leaving them in...then I figured I had better check the bearings while I had it apart. Its a simple process as far as how they are supposed to go togather. But when you have to put all those pieces in as an assembly It gets difficult with only two hands. Oh well ill make it happen. Thanks for the replys!

where are you at ?  if your close i can show you, its ez after 50 times ...............lol !   don't ask why! 

I am in oklahoma. Ive got a buddy who is going to help me once I get the new bearings in.

I am in oklahoma. Ive got a buddy who is going to help me once I get the new bearings in.

Hollar at me when you go to put it together. Id love to get in on that, if Im off. I need to learn more on that before I tear into mine.

always best to learn on someone elses..............................lol ! 

I have installed YZ250 gears both ways - into the right case and into the left case. The left case is BUNCHES easier. The manual also states that the gear clusters should be installed into the left case. You are doing that right.

so you guys install your crank into the left side first also?

so you guys install your crank into the left side first also?

Yes.  The crank should be installed into the left side with a puller and the right side case pretty much slides over everything.

Tried the left handed method without any success. I was way more lucky in the right handed approach. 

Yes.  The crank should be installed into the left side with a puller and the right side case pretty much slides over everything.

Another yes here - install the crank into the left case first. As you can see different people use different procedures. Left works great for me and right (first time) took forever!

make sure your shift forks aren't upside down also when you turn the shaft they will have an end point until the other case half is on, also you will not be able to shift the drum easily by hand. the pics are off my yz250 99 but should give you an Idea, good luck:)  also check out my build thread  http://www.dirtbikeworld.net/forum/showthread.php?t=108383

 

IMG_2001.jpgIMG_1999.jpgIMG_1998.jpgIMG_2002.jpgIMG_2060.jpg

Edited by Two choker

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