Yanmar Tractor Support Message Board

Similarly to a previous post, I have a Yanmar 336d that lost gears 2 and 3 on the power shifter. Its not making any awful noises, and R thru 1 seem to work great. It was like this when I bought it and I don't particularly need the higher gears since I'm on a tight and rough piece of ground but if its a simple fix, I'll probably dig in. I am mostly worried that it might be a harbinger of the other gears dropping out as well. Other than that, and a few minor things like the headlights not working, it seems to be a great little tractor that only set me back about $5K with a YFL 1500 loader.

I'm pretty new to tractor ownership. Any ideas where to start troubleshooting this one?
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Yanmar 336D
Colorado Springs

It sounds to me like it may be a problem with the power shift valve or it may be a problem with the powershift clutch pack for gear 2&3 (in the same pack). It makes it a little hard to say since you got it that way and there is no previous history of what could have happened to cause the problem.

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Aaron
Contact Me
(940)592-0181
http://www.HoyeTractor.com

Since yours is not a "grey" there should be English manuals for it (Service, Parts, Operators).

A follow up from a powershift issue I was having a year ago.
When I first purchased the tractor gears 2 and 3 didn't appear to work.

Now I've found that when I'm out and its cold (between 0 and 40 F as I predominately bought it for moving Colorado snow), the higher gears work reasonably well but slightly sluggish and 3 works slightly better than 2. In warmer weather they seem to go out again unless I can get up a good bit of speed or something. In colder weather I can cycle between gears for quite a while and it will still work. C and 1st gear always work but for the higher gears it seems temp related but I would have thought the fluid would warm up enough after running an hour that this might not matter. I always warm the engine up with a block heater and let it idle quite a while after starting in cold weather so I'm happy but perplexed. Its a consistent trend for many different days of operation now.

Anyone have any better ideas as to why this might be? Clutch? Filter? Fluids?
Is it possible that just cleaning the trans/hydraulic filter would fix the problem? That seems to cure a lot of ailments for folks on this board. I did have the JD dealer change all the fluid and filters when I bought the thing but maybe they "overlooked" that filter or worse, put an incompatible one on (althought this would cause me to think the low gears wouldn't work - but I did see the caution on the Hoye webpage)
Also, where is the darn filter/screen on a 336d and if I do remove it am I going to be able to do it in a manner that doesn't require me to change all the fluid or should I just plan on buying more fluid? I only ask because it will determine how much of a mess I make on the driveway and whether or not I need to plan a trip to town (I'm pretty remote)
The picture in the manual isn't too good or maybe my copy is just deteriorating.

Thanks!

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Yanmar 336D
Colorado Springs

Correct me if I'm wrong- there is no slippage in 1st or reverse? The problem is only with 2 & 3?

The screen is locate behind the 3 bolt plate under the pto shaft. Replacing the filter, cleaning the screen, & replacing the fluids would be my first step. Just to be sure.

If those are all ok then you need to see if possibly the Teflon sealing rings on the powershift selector valve are leaking - there are 5 of them. That would be my next step.

Letting those clutch packs slip like that WILL cause serious damage. They are not designed to slip. They have linings on them just a few thousands of an inch thick. You need to find/fix the problem or you will be looking at seriously costly repairs (may be too late).

PS- I have deleted your new duplicate post to maintain the continuity of this topic.

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Aaron
Contact Me
(940)592-0181
http://www.HoyeTractor.com

You are correct - no slipage in 1st or reverse.

That would cause me to suspect its more likely the clutch paks and not the fluid/screen. I'll change it all out and work down the list as you describe, but it seems like fluid and filters would be more likely to affect all the gears right?

Thanks for the quick response!

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Yanmar 336D
Colorado Springs

I might note that any clutch slippage is much more likely to occur first/most in the higher gear ratios, (2nd & rd), than in the lower, (1st & reverse). If you want to test for a slipping clutch in your stick shift car, try starting off in the highest gear.