Popping out of gear

[8ball3290]

Looking for some help, I've posted on Yanmars boards, but really need advice.
My ym2000 pops out of high range when under load. Lets say i'm pulling my brush hog, not mowing, it will jump of of high range. I opened up the shifter box and the forks appear intact, and the gears look fine to me although I am clueless as what I am looking for as far as damaged gears etc.. It also has never been able to shift into all gears since I picked it up. This weekend I pulled the shifter assembly off, checked things out, lined up the forks and the gears and it was running fine. Was able to shift into all gears, and it didn't pop out of high range. The next morning I put my c-tine cultivator on to work up the pumpkin patch, and it ran fine for about 15 mins or so. when I stopped the shake off some extra vegatation from the cultivator, the only gear that worked was 1st and reverse was in the neutral spot... help. Pics of gear box and forks below. Are the forks suposed to move easily up and down the shafts? Mine do not however I can feel when they pop into the grooved area of the shaft. Also how do you get to the ball and spring, I assume you pop out that pin, which way... sorry I am completely clueless when it comes to mechanical stuff.

 

[RoyJackson]

Re: Pooping out of gear

Might want to edit the title of your thread, friend...you can do this if you select the "advanced" options when you click edit

 

[winston1]

8ball,

I'm attaching this drawing here because I can't do it with clarity on Yanmar Tractor Support. Thought it might help you identify all your gears.

 

[8ball3290]

I've got quite a few manuals which I Stated going through last night. They are mostly in Japanese, but like I stated I'm going at this blind an usually what happens is I'll jack it up worse than what it was before. So tryin to get some sound advice and save a few $ before taking it somewhere

 

[careyo63]

From the Pic all the Gears look fine the shifter forks also look good.I've seen a H _ _ _ of alot Worse. Multiple springs and detent balls going bad Very Doubtful. If it won't shift into gear and or stay in Gear Then I would be looking Hard at the Shifter assembly. Esp.The Shift Lever or the Swivel/Ball at the bottom the Shift Lever which also maybe bent and were it seats on the Shift Lever Guide. Or the shifter Guide itself. Almost have to be. My guess it's either Bent,Warped,Worn and won't let the fork move the Gear far enough to go into gear or if it barely does but not far enough to lock in to the Detent Ball and Spring. I'm almost willing to put money on it. See if Hoye can email you a pic of a good used Shifter and replace it or if you can email them one and compare them. Just Guess but a Real good one

 

[8ball3290]

Thanks man. I will start there, I brought the shift assembly home with me so I'll take a look at that.

 

[Doppelgangar]

The ball with the slots on the gear leaver wears.. Take it out of the housing and you will more than likely see were the retaining pins are warned.

the retaining pins are also more than likely warn and will have to be replaced.

these pins will more than likely have to be made.

Taking then out is easy as just grind off the rivited end and punch the pin out. Don't drop them in the gear box.

as for repairing the slots you can use brazing or metal weld. you can file the slots square to the correct size.

 

[8ball3290]

Ok i got the shift assembly apart heres some pics... dont know if any thing is wrong or not the shifter rod itself looks a little out of wack, but i have nothing to compare it to right now. All the parts were together and accounted for and not broken. that last pic is way fuzzy but it looks kinda bent to me.. anyone else think so also.

 

[winston1]

I can't see any bend other that what is suppose to be there. Don't mean it's not bent. How is the fit of the ball on the shaft and the pin going through the ball? Does the ball seem to fit tight when it is up in the housing?

 

[Car Doc]

I see what looks like someone has staked the last shift fork with a center punch. I presume to take up clearance (but why?) on what I believe from what I see is the reverse fork.

The middle fork (3-4?) has what looks like quite a bit of off center wear also. I wish I knew how to draw on these pics I would show you what I am talking about.

As to why I cant tell you but looks like if I am seeing what I think someone else has already been in it and that always makes me nervous.

I will say this that on non-sycromesh tranys the ball detents in the shift housing on the shift shafts are what hold the trans in gear. They have to be right since there are no syncro clutchs which have shift dogs that have detents in them also. Everything has to run paralel also meanaing no bad main shaft or counter shaft bearings.

edit: The shifter looks fine btw. I presume it fits the shifter socket snugly? Some tranys have a plastic bushing pushed on the end of the shifters on the small ball and that can cause gears not to be engaged far enough but if it doesn't have one and it fits snug it is for sure ok as long as the shifter seat is good and that is the seat which the larger ball with the pins pivots and sits in and keeps pressure on the big ball with the pins so it doesn't move up and down. (sorry this is hard to explain in detail on 1 dimensional internet. I guess what I am saying is its very likely the shift tower rather than the bottom end better than 50/50 anyway.)