Posts
480
Joined
2/23/2015
Location
Byhalia, MS, USA
Edited Date/Time
5/15/2024 7:58pm
Bought a blown up yz a couple months ago and been rebuilding it. Done a few bottom ends and they always seem to be a little different from the next. Anyways I got the transmission in and put the case halves back together but can't get the transmission into neutral. Shifts through all the gears fine with no binding but when I put it where neutral should be the output shaft still spins. Tried rocking it and stuff but no luck. Before I resplit the cases has anybody has this happen? I know in my kx it wouldn't shift through the gears until the case halves were torqued. Curious if this is some oddity or if one of the shift paws fell out of the drum or something.
Did you put the transmission in one side of the crankcase and check it went through the gears, before assembling the other crankcase?
Yes of course. It shifted through the gears and into neutral. Though it is harder to shift that videos I've seen online. The pins the shift dogs are on kind of twist when shifting without the other case half on. When I put the cases together it still shifted through all gears but when I lined it up for neutral the output shaft won't disengage.
I went ahead and split the cases again just to double check everything and it all looks fine. Just such an odd problem.
Also after splitting the cases it goes into neutral properly again. I can't see any washers or spacers on the diagram that might have fallen during disassembly.
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In my opinion, you have to build the YZ transmission in the right engine case half, then install the left engine case after you check it.
The right case half locates the shafts and the shift drum relative to each other.
I would pull everything out and go through it piece by piece to ensure you aren't missing or doubled up on any of the thrust washers or shims. Also, carefully inspect your shift forks.
Once you've dropped everything in the right side case, check through the gears and watch closely to see if any dogs are dragging.
The terrible shift fork design still allows a lot of misalignment without both cases assembled.
This may be too obvious but I will suggest it anyways.
Just make sure when it is in the neutral position that you hold the output shaft independent of the clutch shaft. There is enough drag that if you do not hold one both will still spin despite being in neutral.
I had a similar issue. Could get neutral without the case closed up. Once together the tranny would spin and lock up in neutral. 3rd time splitting I discovered I had one gear facing the wrong way. 3 gears slid off and I was convinced I put them back properly.
If the tranny will function correctly without the left side case half on you almost certainly have a gear or shim that needs to be orientated correctly. This has been my experience.
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