F17d Long Term Impression Update

[wannabeefree]

Well almost 2yrs ago I posted a first impression and thought I might give a little update on my experiences so far. First the Tractor has run flawlessly, starts easy and seems to be mechanically in great shape. Functionally everything works just about as well as can be expected for a 30+ year old tractor. As to power and its ability to do what I have needed to do with it, I would say it has been good , not great but adequate for my usage. There are times when I wish it was a little bigger tractor and the Loader is not as powerful as I would like. I often put some slip on Forks on the bucket and the single hydraulic ram for tilt is a little week and not as stable as I would like but mostly it gets the job done for light to moderate lifting. The rear 3 point is amazingly powerful for such a small tractor. I recently found a deal on a 5ft 16" 3 point disc harrow that I was afraid might be to big this little thing but it seams to work fine for my soil and small pastures. One thing that I wish I had was a hydro static shuttle transmission but truth is I think the Geared transmission puts more power to the ground and is why this little tractor is able to pull some things better than some more modern/powerful fluid drive tractors.

Overall I would say I am pretty pleased with my purchase to date.
I would like to here some other impressions from similar models.

 

[CoyPatton]

It is my opinion that a true gear drive tractor will always put more power on the ground than the same engine HP fluid drive (shuttle shift or hydro) tractor. Some argue this but comparing PTO output HP tends to support my opinion as does 3PH lift capacity.
I have an older style YM2002D and am constantly surprised by the performance of my little yannie. I to find the loader could use a bit more in the hydraulics, but you accept what you have a work with it. When I bought mine I have some width constrictions that were not an easily changeable option, so physical size was a big factor. Overall, I would recommend a YM series to anyone that finds one sized to do what they need to do and is capable of turning wrenches.

 

[ptsg]

It is my opinion that a true gear drive tractor will always put more power on the ground than the same engine HP fluid drive (shuttle shift or hydro) tractor. Some argue this but comparing PTO output HP tends to support my opinion as does 3PH lift capacity.
I have an older style YM2002D and am constantly surprised by the performance of my little yannie. I to find the loader could use a bit more in the hydraulics, but you accept what you have a work with it. When I bought mine I have some width constrictions that were not an easily changeable option, so physical size was a big factor. Overall, I would recommend a YM series to anyone that finds one sized to do what they need to do and is capable of turning wrenches.

You mentioned shuttle shift but I think you wanted to say hydraulic shuttle shift or power shuttle or power reverser. Which, is not a considered a fluid drive and will put all the power to ground like a dry clutch tractor will.

 

[CoyPatton]

You mentioned shuttle shift but I think you wanted to say hydraulic shuttle shift or power shuttle or power reverser. Which, is not a considered a fluid drive and will put all the power to ground like a dry clutch tractor will.

I have a friend that has a YM2610, from him I understand that his shuttle shift has a fluid pump system on it that acts kinda like an automobile automatic transmission to allow the power shift or shuttle shift to function.
I consider that to be a fluid shift and will reduce the power to the ground. Less reduction that a HST but still reduce power to the ground compared to a same engine HP tractor that is strictly gear drive.

 

[ptsg]

It's a powershift. Uses an oil pump feeding the valve (works as gear shifter) and then engages clutch packs accordingly to the gear you choose. The fluid just engages the clutch packs and won't actually drive the tractor like an HST.

Here is a good write up on the differences and how it works. It's from Hoyetractor that deals with these older Yanmars.

Yanmar's Powershift Transmission explanation.

 

[California]

A simple way to think of Powershift is its the same as a car A/T. Except its missing a car's torque converter (fluid coupling) at the transmission input. The shaft from the clutch goes straight in to the transmission.

You let the clutch out. This spins the small pump inside the Powershift. That fluid engages the clutches inside the Powershift. After that moment you have a direct mechanical connection from the engine to the tires. Control which gear its in, using the shifter which directs fluid to various gear paths.

The reason this seems intuitive to me is because it is similar to early GM Hydramatic. Cadillac and Oldsmobile before about 1953 had a fluid coupling that would lock up to a mechanical link at highway speed. Offroaders and drag racers experimentally modified those Hydramatics to shift so firmly that it amounted to a mechanical 4 speed ... perfoming like our Powershift.

These guys were specialists in race-modified Hydramatics back in the day.
B&M Transmissions.

 

[ptsg]

It was quite a feature done by Yanmar on these small tractors at the time. This basically turned a transmission PTO into a Independent PTO.

Yanmar has always been very innovative in some of the small tractor features.

 

[California]

It was quite a feature done by Yanmar on these small tractors at the time. This basically turned a transmission PTO into a Independent PTO.

Good point. Engage the clutch and you have a mechanical path back to the PTO independent of the transmission which turns the tires. It's very handy to engage a mower while standing still, then a few seconds later shift to a forward gear to start moving.

 

[wannabeefree]

I have to admit I know very little about Shuttle Shift. My original post was referring to HST or fluid coupled transmission. To me it only makes sense that there is bound to be some loss of power to the rear wheels or PTO if being transferred via a fluid drive system. On the other hand I am not sure if Power or HP is being measured the same on modern Tractors or not. I know on Cars there is a big difference in brake and rear wheel horsepower. Maybe someone more knowledgeable can address that. For instance there are a lot of old 8n Ford tractors out there that were only rated at about 27 hp yet that out pull some modern 40 hp tractors.

 

[California]

...I am not sure if Power or HP is being measured the same on modern Tractors or not. I know on Cars there is a big difference in brake and rear wheel horsepower. For instance there are a lot of old 8n Ford tractors out there that were only rated at about 27 hp yet that out pull some modern 40 hp tractors.

You have a Yanmar so this explanation should make sense. (Others reading this may find it new).

Yanmars sold in Japan, including yours, use the hp available at the PTO to drive a rototiller, as part of the model name.

In contrast, Yanmars built for sale in the US use the US custom for rating hp, and carry this into the model name: the hp of the engine on a test stand coupled directly to the dynomometer and with no accessories attached.

The classic example in the Yanmar world is YM2000 (Japan) has the same identical engine as YM240 (US). 24 hp was rated the same way as the old Ford 8N, engine on a test stand. Vs 20 hp measured at the PTO after 4 hp lost in the gearing, for the YM2000. Same tractor, different marketing.

Incidentally that 8N will way outpull a YM240 because it weighs 50% more. There's a greater difference than the 27/24 hp ratings would suggest.