# Loss of drive yanmar186d



## Ghostwhotypes (Feb 8, 2020)

Hi all, I have just bought a 2nd hand 186d and it has trouble driving in all gears forward and reverse
When it does engage it drives well.
Sometimes if you put it in gear it will not engage and the gradually engage and then fully engage.
The clutch pedal does feel like it's just about 1/2" from final travel before engaging even when it is working well

Any help greatly appreciated
Mike from Australia


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## Hoodoo Valley (Nov 14, 2006)

Welcome to the forum Mike! We have a few "spot on" mechanics here that will be able to help you out.


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## winston (Aug 19, 2008)

Your pedal should be adjusted to have appx 5/8" free play at the top. If it is adjusted that way and slipping you are likely facing a split. It is normal to see more slippage in higher gears when the clutch is going out.


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## bmaverick (Feb 20, 2014)

Ghostwhotypes said:


> Hi all, I have just bought a 2nd hand 186d and it has trouble driving in all gears forward and reverse
> When it does engage it drives well.
> Sometimes if you put it in gear it will not engage and the gradually engage and then fully engage.
> The clutch pedal does feel like it's just about 1/2" from final travel before engaging even when it is working well
> ...


Welcome Mike.

Ah the typical, the Yanmar trouble moving forward and reverse and issues with the 3PT moving. 

EASY answer, I one hope, is to clean the hydraulic filter or replace it. Also, since this is a hand-me-down machine, I would strongly recommend changing the hydraulic fluid. Typically, these YM Series along with the F & FX use the John Deere J20C fluid. Do not use the JD303 as it's been obsoleted for tractor use for the past 45+ years and is strongly not recommended for the Compact tractors we have. 

For winter use, the oil to use is 5W30. These compacts run sluggishly on 15W40. Yanmar recommends 5W30 for most operation temps. There is a thread here with both the Yanmar and JD charts. 

Why recommend John Deere fluids? Well, Yanmar has been making their tractors for John Deere for the past 40+ years. Just painted JD green  vs. the Yanmar red . 

Also, your manual is located in the sites' MANUAL section. Poke around, and you should find it easily.


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## winston (Aug 19, 2008)

Tractor Data shows the 186 as a geared transmission which is evidently wrong. So your tractor is a power shift?


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## Ghostwhotypes (Feb 8, 2020)

winston said:


> Tractor Data shows the 186 as a geared transmission which is evidently wrong. So your tractor is a power shift?


Yes a powershift transmission


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## Ghostwhotypes (Feb 8, 2020)

bmaverick said:


> Welcome Mike.
> 
> Ah the typical, the Yanmar trouble moving forward and reverse and issues with the 3PT moving.
> 
> ...


Will do a filter when I get home, 
The screen was pretty clean and I had to put 7 litres of oil in it


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## Ghostwhotypes (Feb 8, 2020)

W


winston said:


> Your pedal should be adjusted to have appx 5/8" free play at the top. If it is adjusted that way and slipping you are likely facing a split. It is normal to see more slippage in higher gears when the clutch is going out.


I'll check thanks


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## Ghostwhotypes (Feb 8, 2020)

Ok so more data, i put a gauge on the rear port and the pressure build up is exactly as you would expect , 0 with no movement and gradually climbing until about 100psi then rapidly to 190psi where it seems to regulate quite strongly, its like another valve is not closing correctly and then it does?


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## winston (Aug 19, 2008)

Not sure about your test. Thinking you are getting your readings from the rear side plug on the regulator case. Is that right? I have a 226 manual so can only speak for it. Would assume it would be pretty similar to the 186. With a gauge in that position, fluid warmed to 104 to 122 degrees F, range shift lever in neutral, the pressure is to read 213 to 227 psi with power shift lever in R, 1,2, 3 speed positions.

These are the springs people sometimes have broken. https://www.hoyetractor.com/PROD/194446-24540.htm
https://www.hoyetractor.com/PROD/194446-24550.htm


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## Ghostwhotypes (Feb 8, 2020)

Yes you are correct, but initially it is 0 psi and takes around 30secs to gradually build to 199 psi


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## winston (Aug 19, 2008)

Out of the 226 manual.


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## bmaverick (Feb 20, 2014)

Ghostwhotypes said:


> Yes you are correct, but initially it is 0 psi and takes around 30secs to gradually build to 199 psi


Do you have youngsters at home or ones that visited? Kids like to sit on a tractor and imagine it's a race car, or truck or even the tractor as is. With that said, they will pull and yank on EVERY LEVER their little hands can find. 

So, under the seat are a few levers and the wheel-knob. And looking from the rear of the tractor there are an additional 1 or 2 depending on the model. IF any of these were touched, chances are your problems could be solved by first taking note what position they are currently at. Then move it left/right or up/down. Take not of any changes. Keep working your way around. There is a tiny lever about 1 or 2 inches long. It's not that obvious it's a lever. Still under the seat on the left side when you are seated on the machine. 

Report back if anything was noticed or improved or FIXED.


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## Ghostwhotypes (Feb 8, 2020)

Will do, thanks


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## Ghostwhotypes (Feb 8, 2020)

So far
Only 2 adjustable screws under seat
One for 3pl
the other for PTO
I pulled the hydraulic valve on the transmission apart and found the inner spring broker, the delay relief valve was stuck down and the gasket was bypassing oil, will fix these and see what it is like.


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## winston (Aug 19, 2008)

sounds like you have found the problem.


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## Ghostwhotypes (Feb 8, 2020)

i ended up making a new spring and removing the 2nd pressure relief valve and cleaning the mating surfaces


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## Ghostwhotypes (Feb 8, 2020)

still has a delay in building to the pressure required for drive
Is this normal?
lubrication pressure is only about 3 psi instead of 6psi, is this going to be an issue once it is driving its a great machine.


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## winston (Aug 19, 2008)

[ATTA







CH=full]56727[/ATTACH]


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## bmaverick (Feb 20, 2014)

winston said:


> View attachment 56727
> [ATTA
> View attachment 56727
> CH=full]56727[/ATTACH]


It's a bit hard to read. I even used the keyboard CTRL and plus+key.


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## winston (Aug 19, 2008)

this may be as good as it gets.


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## Ghostwhotypes (Feb 8, 2020)

It might be a seal internally , I have a 2nd hand transmission coming, I might pull it to bits and see how it works, I'm thinking the 2 faults are related


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