Thoughts on GST transmissions

[RickB]

The GST may or may not be for you, but it is an excellent and very reliable transmission that doesn't whine. Sounds to me like that Kubota salesman doesn't know what he is talking about....lot of that going around.

Personally I'd prefer a used GST over a used HST.
If it's a tractor you want to use for a year and resell then I'd pass.
If it's a tractor you plan to keep for a few years you may become a GST convert.

Agreed.

 

[npalen]

- Messicks.Ecommerce

Found this article and video from Messick's meanwhile.

Edit: He doesn't mention IVT transmissions but I would think that be the "Cat's Meow" in a compact tractor.

 

[Fallon]

What is the difference(s) between the Kubota glide shift and, say, a Deere powershift? Does moving the shift lever on a GST actually slide and mesh the gears or is it all done with several hydraulic clutches?

Generally not much to my understanding.

GST is a single wet clutch. The JD PowerShifts I drove 20 years ago were a double clutch design I believe. Shifted a lot faster than GST. Also different class machines in price, weight & HP so not necessarily an apples to apples comparison.

GST & generally PowerShufts don't have a direct mechanical link to shift forks like a manual. It's done hydraulically.

 

[npalen]

Generally not much to my understanding.

GST is a single wet clutch. The JD PowerShifts I drove 20 years ago were a double clutch design I believe. Shifted a lot faster than GST. Also different class machines in price, weight & HP so not necessarily an apples to apples comparison.

GST & generally PowerShufts don't have a direct mechanical link to shift forks like a manual. It's done hydraulically.

The Deere powershift I'm familiar with is in a 8420 that is about 20 years old, 200 plus HP and 10K hours on it. It's 16 speed with 26 MPH top end and there about four ranges that make up the 16 speeds. Shifting between ranges is fully automatic also but there will be two clutches involved and it takes a noticeable split second longer than changing gears within a range. It is an excellent tractor for pulling a 800 plus bushel grain cart during harvest with the powershift. Fifty thousand pounds of grain can be noticeable, however, even with this big FWA tractor.

 

[Fallon]

The Deere powershift I'm familiar with is in a 8420 that is about 20 years old, 200 plus HP and 10K hours on it. It's 16 speed with 26 MPH top end and there about four ranges that make up the 16 speeds. Shifting between ranges is fully automatic also but there will be two clutches involved and it takes a noticeable split second longer than changing gears within a range. It is an excellent tractor for pulling a 800 plus bushel grain cart during harvest with the powershift. Fifty thousand pounds of grain can be noticeable, however, even with this big FWA tractor.

Similar to what I remember... JD 7 & 8 thousand series. When plowing they could often upshift automatically. Manually if you tapped the clutch not even shifting you'd stall the machine. At least between some of the gears. Blew my mind then & still does to some degree now.

Some of the machines were power quads. Basically a 4 speed manual + a 5ish speed PowerShift.

But those were $100k+ tractors then. A GST is generally a sub $50k machine. 1, almost 2 second shifts in many cases instead of 1/8 of a second.

 

[MHarryE]

When I retired, I started driving tractor for my cousin, 2 JD’s with 20 speed power shifts, 5 ranges, 4 power shifts in each range. Not always possible to shift ranges without stopping but the power shifts great. Then I started doing some farming of my own and bought a Kubota power shift, 3 ranges with 8 power shifts in each range. Much better having 8 power shifts but harsher than the JD. Four years later another upgrade to a Kubota CVT. Like 0.3 mph to 31 mph single range. The cost - looked up the replacement transmission cost on Messick’s and it’s like $20,000 more than the entire cost of my L6060. That’s what comes from adding a pair of hydro transmissions to a pair of power shifts. I assume that’s why the CVTs of that type don’t make it into the lower power tractors. The one sold by Case and New Holland is a V-S chain drive.

 

[npalen]

Similar to what I remember... JD 7 & 8 thousand series. When plowing they could often upshift automatically. Manually if you tapped the clutch not even shifting you'd stall the machine. At least between some of the gears. Blew my mind then & still does to some degree now.

Some of the machines were power quads. Basically a 4 speed manual + a 5ish speed PowerShift.

But those were $100k+ tractors then. A GST is generally a sub $50k machine. 1, almost 2 second shifts in many cases instead of 1/8 of a second.

That's interesting! Does a 1 or 2 second shift under full load tillage result in a very noticeable loss of momentum?

 

[npalen]

https://agriculture.newholland.com/nar/en-us/equipment/products/tractors-telehandlers/boomer-3000-series/features/transmission-easydrive-cvt

Chain drive--guess we've gone full circle.

 

[Fallon]

That's interesting! Does a 1 or 2 second shift under full load tillage result in a very noticeable loss of momentum?

It was more like a 0.25 second shift under most circumstances going up or down 1 gear. There were a few instances I could upshift under full load successfully. Same conditions, same starting gear if I tapped the clutch to the floor & let go as fast as I could (no shifting) it was enough to stall the tractor. Mind blowing how fast a dual clutch system can shift.

There was a bit of lag between hitting the lever & the start of the shift. But the time between the start & finish of the shift was dam quick. Going up or down multiple gears was a fair bit slower though.

Not sure if those machines use planataries like an automatic or just multiple hydraulically actuated gearboxes more like a classic manual transmission.

 

[RickB]

It was more like a 0.25 second shift under most circumstances going up or down 1 gear. There were a few instances I could upshift under full load successfully. Same conditions, same starting gear if I tapped the clutch to the floor & let go as fast as I could (no shifting) it was enough to stall the tractor. Mind blowing how fast a dual clutch system can shift.

There was a bit of lag between hitting the lever & the start of the shift. But the time between the start & finish of the shift was dam quick. Going up or down multiple gears was a fair bit slower though.

Not sure if those machines use planataries like an automatic or just multiple hydraulically actuated gearboxes more like a classic manual transmission.

Why would you use the "clutch" pedal if the transmission was a powershift?