Early Power Shift Tractors

[Farmwithjunk]

The bottom line is, Deere made it WORK, and made it happen (successfully) long before any one else. (First released in 1964) The 8-speed powershift didn't offer the speed selection of the Case/IH Powershift, but Deere had their offering on the market more than 20 years prior to the Case/IH version. And by that time, Deere had gone to the 15-speed version. Percentages aside, shortly after Deere introduced the 4020 Powershift, they made a slight "adjustment" to PS equipped tractors. They uprated the horsepower by a measly 3hp over Sycro-Range models to give them equal performance "in the field". Specs, test data, opinions, and sales propaganda aside, the Powershift gave excellent performance, extremely reliable service, and had the market by the horns long before any other version could compete equally.

 

[JasG]

Renze:

All I can speak of is what this engineer told me. Also please keep in mind I was speaking of power to run the transmission only. You can not take PTO, or draw bar pull and equate it to transmission efficiency. My numbers where for transmission only, no different than crankshaft Hp. Crankshaft power is measured with nothing attached to the motor, not even a water pump. If you go by draw bar you will have a much greater loss. In the draw bar you have the loss from the alternator, fan, water pump, hydraulic pump(s) and anything on the machine. Also the friction losses from movement. You also have the weight of the machine, which works against it. I do believe Farmwithjunk is also correct that the 4020 PS had 3 hp more on the engine, this alone would be over 3%. When you take into consideration all of the other losses it puts me into the 5% ball park needed over a manual to get the same pull.

I also did mention in my post the 4255 was lighter, I just have no way of knowing how much lighter. Both tractor had weights added. Deere since the 4000 model has set up most of there tractors with higher hp to weight ratio's. This was a very smart move to allow a person to upgrade in Hp without buying all new implements. This would allow a guy with say a 4 bottom plow to pull it fast enough to plow the same amount of ground as another brand of the same HP pulling a 5 bottom plow. The 4000 model had a 4020 engine, but was about 1500-2000 lbs lighter. I worked for a guy who had both a 4020 and a 4000 and you noticed a huge difference in the way the tractors pulled.

 

[RickB]

Renze:

All I can speak of is what this engineer told me. Also please keep in mind I was speaking of power to run the transmission only.You can not take PTO, or draw bar pull and equate it to transmission efficiency.

You certainly can if the transmission is the only variable. Nobody measures HP at the transmission output shaft.

The 4000 model had a 4020 engine, but was about 1500-2000 lbs lighter. I worked for a guy who had both a 4020 and a 4000 and you noticed a huge difference in the way the tractors pulled.

You run them hard side by side, you will also notice a huge difference in how long before a final drive failure.

 

[JasG]

RickB:

There are more factors involved than just the transmission when measuring from the drawbar. All you can measure is total drive train efficiency with a draw bar test. That would include the transmission, differential, final drives, rolling resistance, weight, tires, tire pressure, wheel slip, etc. That is one of many reasons the Nebraska test no longer lists draw bar hp. They list drawer bar pull, along with speed, and engine Hp in different gears and different engine speeds. Due to draw bar hp can be manipulated by tire size, pressures, etc.
I can also speak as an engineer who has spoke with many engineers in the Ag industry over the years. The big guy's, Deere, Case IH, New Holland etc. They know what every part of the tractor needs for power. From the AC compressor and fan blade to tires and hydraulic pumps. It's such a tight market that every little bit helps get a leg up on the others. That is why they have gone from standard fans to varidrive. That little bit adds power that can be used in other area's.

As far as final drives go I don't know of any that have failed without a good reason. I know some people that have added turbo's to 4000's and beat the tar out of the tractors. This goes for any brand, Deere, Case, IH, etc. I only know of one that blew his rear end apart. That was on a IH two plus two that was putting out twice the rated factory hp. Had duals all the way around and pulled an liquid honey wagon and an oversized set of plows it's whole life.

 

[RickB]

So you are an engineer that has talked to other engineers. You claim that a Deere 4255 will "run circles around" a CIH 7120 whose powershift you describe as "not very good" despite the massive popularity of CIH 71XX, 72XX, and 89XX tractors based on their durability. And you have never seen or heard of a Deere final drive that was underdesigned to the point that it failed, despite those failures prompted running production changes in those very parts. I refuse to debate this further.

 

[redneckford]

RickB-----JD had a good powershift for a long time----Ford "HAD" a good "TRACTOR" for a long time---the others had-----more farmers went broke farming with JD tractors than any other brand----JUST FACTS----!!!Quality has its price---sometimes it is just more than the market can bear----higher price--- more interest paid--- on equipment repairs and parts!!!!!!

 

[JasG]

Rick:

Yes I am and engineer and belong to the SME. The 1st Case IH power shift transmission did have many updates over the 1st couple of years. I actually drove several models in the late 80's early 90's. They held up OK, but as I said try doing loader work with one. They were very slow backing up and did have issues putting power to the ground. Have you ever drove one of the early ones? Plowed, chopped, etc? I also stated I only know of 1 tractor reguardless of brand that had a final drive fail. Most brands so over built the final drives they would easily take twice the hp. Do you have any idea the number of tractor with after market turbo's? Or have had the pumps turned up? Look at some of the other posts here that people know of tractor that have survived since the 60's without a drive train issue. I suppose they are not telling the truth as you imply with me? I have a friend with a 1969 model with around 20000 hours (total frame, not engine). Other than a few clutchs the transmission has had no issues. Until 5 years ago this was the primary tractor on a 200 acre farm. Why is it that a 4020 and even the 4000's at auctions are going to more money now than they sold for new? Because they hold up.

As far as "massive popularity" people are very brand loyal. Even when they make something less than what people are use to. Look at the Deere 30 series and the HFWA models. In my opinon the motors on the 30 series were a step backwards. The HFWA only help get you more stuck. Yet people keep buying them and still do to this day.

 

[backdoor]

I worked on a dairy farm in the mid '80's where we had a 100 HP Case with a powershift trans and no modifications to anything. Final drive parts broke on that tractor, a tooth broke from the pinion gear, and several teeth broke from a bull gear. Both bull gears had cracks or chips in the teeth. I'm not sure that tractor had a powershift like you guys are talking about or not, it was the only farm tractor powershift I ever drove. I'm not a mechanic in any way, I saw the broken stuff, but the other guys had to tell me what was going on.

 

[JasG]

Charlie175:

Actually your question was who was able to get it to work.

Caterpillar - Dozers, some ag products

ZF - Makes drivetrain parts including transmissions for OEM's, I think mosty in construction equipment.

Funk - Makes Transmissions for OEM's still does, but now is owned by Deere. Customers are many, Ford/New Holland, McCormick, Agco, Massey Ferguson, Bulher and many more. I don't know if New Holland still uses them since they went with the T-series a few years ago.

International Harvester (They had the transmission done before being bought by JI Case)

I'm sure there are more, but these are the ones I know of.

 

[Renze]

Crankshaft power is measured with nothing attached to the motor, not even a water pump. If you go by draw bar you will have a much greater loss. In the draw bar you have the loss from the alternator, fan, water pump, hydraulic pump(s) and anything on the machine.

It depends on what standard you do the test: some tests just measure a bare engine without even the water pump. This test was done according to ECE R24 which means real horsepower, just bolt off the transmission and measure the actual engine hp as a reference, to compare to PTO and drawbar hp.

Also the friction losses from movement. You also have the weight of the machine, which works against it.

To me it sounds like the test is a fair comparison. In farm practice the rolling friction of the tires, and the inertia of the tractor body, play the same role as in testing conditions.

However i'll look into that test report once more, to see if it was an actual drawbar pull, or a bench test...