Is it nessesary to remove the transmission to replace crank,bearings and seals? In this video,
Could I just leave all the stuff on the left side of the crank where it is? He leaves it there until after splitting his cases, is this the better way to do it?

Edited by DrDuke, 04 April 2012 - 08:05 PM.

Dang that guy in that video is a hack! Hacking away with Craftsman tools. Thats probably what ya get at most dealerships these days. Hacks with sub-standard tools.

mrmoto35, on 04 April 2012 - 09:54 PM, said:

A hack for using affordable decent quality tools? I forgot how not having enough money to blow on Snap-On tools makes me, him and everyone else with Craftsman tools a hack?

The transmission does have to come out to make it easier to work on each case half individually, but you can just remove the shafts and gears as a unit, then slide them back in afterwards.

Lead Head, on 05 April 2012 - 06:44 AM, said:

No Sorry man wasn't trying to insult anybody. I was referring to dealerships and thinking all the negetive comments about dealerships I have read here. It was late, I was very tired and I was thinking about a dealership here in SoCal. The few times I took my bike there it would come back leaking oil, bolts loose or missing, things installed backwards..... Worked out ok though as it got me working on my own bike again.

When the guy in the video is running the air impact and holding the piston at the same time, had the piston moved enough it could have bit him good. Same thing with the sprocket. 99.9% of the time it may not happen but ya never know.

Edited by mrmoto35, 05 April 2012 - 10:49 AM.

I had to stop watching the vid at 1:47 in. What an absolute hack. That guy will be missing a finger or two before he dies. And out of shear stupidity.

Why didn't he take the cam chain guide off when he took the damn stator off...why did he stop and go to the other side before one side was done? I dont even want to know.

I wouldn't let that guy change the oil in my lawn mower.

To the original question; its easier to just take the trans out. Pull the shift drum and the shift fork guide rods. Pull the shift forks out, and lift the transmission up and it comes right out. The input side in the left hand, the output side in the right hand. You can leave it completely assembled. When you put it back, put it back exactly the same way in reverse.
Make sure the transmission spins, done. If it doesn't spin, you need to align the shift forks and get the trans into a gear or neutral. Its easier if its in gear though. Just make sure the drive dogs are all the way in.

I made an case cradle that allows the input shaft to hang out so the cases sit flat on the bench. Its just a stacked up pair of 2x4's drywall screwed together in a nonparallel  box. Makes loading the cases super easy and stable though. Worth the 10 minutes it took to make.

Shawn_Mc, on 05 April 2012 - 09:11 AM, said:

Ok, I guess I will try that.. At least then I can check my trans bearings. I remember reading about the stand, what are the dimensions? Also if you are going by the manual word for word when rebuilding, you will first lift off the right side of the case, only too reinstall it, turn the engine onto it's right side and then lift the left cover off and remove transmission. Couldn't I just swap out my right side bearing when I have it on the left side, then "temporarily reinstall" the right side case and flip it onto the right side, replace left crank bearing and crank, then bolt it back together?

Its easier to just take the trans out and set it aside. Trust me, its not going to explode on ya
When I first started doing this, I found the parts fiche to be much more helpful than the manual. The parts list gives you dimensions on the thrust washer sizes too, that the manual doesn't. It also gives you the number of teeth on the gears to identify them more easily too.
It just lifts out. No struggling or yanking necessary.

Depending on your bike, #5 may be changed with #38 (they upgraded the bushing to a roller bearing) and #40 goes inside gear #10. If you notice, some of the gears are retained on the shafts with a snap ring. Only a couple can fall off when you drop the trans and everything rolls down the drive way into the street.   JUST KIDDING!!

If youre nervous about this, have 2 beers before you start. But no more. I just saw a study that people that had been given two beers completed puzzles in 40% less time with and with greater accuracy.

This is not a more is better situation though.   It also only worked with men too, go figure.

Just pulled the trans. It did not come out as easily as expected! It's hard to not let gears slide out, etc. I had to hold the case on an angle and push on the shafts from the other side. Does it matter if the gears moved around a little side to side? If they are in any way timed then I definatly mixed it up. I had to pull the main shaft first, then the countershaft.

With the manual it's easy to put back...

if youre doing crank bearings you might as well do the trans bearings as well, cheap insurance as opposed to having to split them again when the trans bearings take a dump.

No need to get carried away....some of the bearings in there hardly get used at all like the shift drum bearing and the clutch actuator bearings.  Of course then again they are pretty cheap.

I am taking my right side case cover off to inspect for a tang that presumably made it to the oil when inserting a helicoil in two of the oil filter cover threads. One was a through hole, so a 1/4" medal tang in ones engine is unsettling.   Since I am going to be in the gears anyway and my bike is a 2005 yz250f that otherwise runs well, is it wise to replace any certain bearings while I am in there?  If so, what is the approximate cost of replacing those bearings?  If they turn smoothly, is that enough to assume they are in good shape?  I'm 48 and do not race.  This is my play toy, but I don't like doing things twice if i can avoid it for a few bucs.

Does the clutch have to come out first, before the cover can come off or will the entire cover come off with the clutch assembly intact?  Obviously something must be disconnnected first.

Thanks
Eric Klee
Hudson, Fl