Powershift vs direct drive question

Direct drive is thought to be (and I think proven as well although I can't bring any studies immediately to hand) more efficient in terms of converting power to tractive effort. Since you'd be performing long steady pulls rather than forwards and backwards activity such as would be seen with a dozing operation, then operator ease and comfort, and productivity for that type of operation is not a consideration. That heat you feel from the transmission ultimately comes from the fuel you're burning and does not constitute effective work done. Both transmission types produce heat and I don't know if one produces less heat per unit of work done but I would guess that a direct drive machine might theoretically produce less heat, but it would all depend on a bunch of factors such as gear power transfer efficiency, availability of torque convertor locking, lube/pressure pump efficiency which would also be affected by transmission condition / wear, oil condition, etc. etc.
Perhaps Cat published a comparison based on lab and field tests?

If it was the D8 with the cab, I met the old guy that drove it for awhile. His only complaint was no radio and he about lost his mind doing the same slow job weeks on end.
Gear drive seemed to be the choice for most that did orchard ripping here. We had a fellow that burnt one, but not sure if it was accidental or what, since he had overheating issues with it quite often. JM

Yeah, oh the songs that a guy finds himself singing on a long day are quite creative, aren't they? 😁.
Yes that tractor had no blade, just the front counterweight.  
They did some of the ripping with the HD-41 also that was a rental from the boys in Colusa.  That was a big one also.  One day the guys from Caterpillar came out to look, and left in a Huff after Grandpa showed them the broom handle just disappeared all the way down in the trench the 41 left behind the shank 🤣

Back when 46A D8H's were everywhere the 90+ degree temperatures gave them fits ripping for all the new vineyards in the Paso Robles Calif area. But none new anymore ether.One of the disgruntled owner operators took a chance on a Fiat Allis FD 31. He liked it so good he went looking for them. By chance there was one FD 31 still doing a small job a year or maybe 2 by now in a area I drive by often. But that has not answered the question about transmissions.

I would agree with Niels assessment, greater heat developed means more wasted fuel for the work accomplished. But with the cost of parts and repairs, the dollar amounts over years of use may not be what one would guess.

Hi, Tailseat15.
If ONLY straight deep ripping is ALL the tractor is going to be doing, I would go with the direct drive option. There is no torque converter there to either generate heat or require a lockout device. Torque converters are great for dealing with shock loads or keeping engine revs up and allowing the torque converter to build up the power being delivered to the tracks but they do generate heat in doing their thing.

Just my 0.02.

The neighbor to my in-laws has been in the process of pulling out his 20 - 25 year old trees using the whole orchard recycling process. They went out and got a standard high track PS and are ripping, I wouldn’t call it deep ripping as when Fowler was working down the same road they were going about 2/3’s maybe only 1/2 the depth of what Fowler runs. The PS ripper is basically working in a number of 5 - 8 acre little fields as they are trying to save the main lines, laterals and sub lateral PVC lines. So lots of short runs, turns and backing up. That being said the commercial outfit shows up and runs around the clock basically never stopping, in and out in a few day at best, while the PS tractor seems to be sitting at the side of the field more than I see it making dust so there is that.

Juiceman I don’t understand how the guy could go crazy ripping the consensus here is ag work is high speed work 😊

The neighbor to my in-laws has been in the process of pulling out his 20 - 25 year old trees using the whole orchard recycling process. They went out and got a standard high track PS and are ripping, I wouldn’t call it deep ripping as when Fowler was working down the same road they were going about 2/3’s maybe only 1/2 the depth of what Fowler runs. The PS ripper is basically working in a number of 5 - 8 acre little fields as they are trying to save the main lines, laterals and sub lateral PVC lines. So lots of short runs, turns and backing up. That being said the commercial outfit shows up and runs around the clock basically never stopping, in and out in a few day at best, while the PS tractor seems to be sitting at the side of the field more than I see it making dust so there is that.

Juiceman I don’t understand how the guy could go crazy ripping the consensus here is ag work is high speed work 😊

Direct Drive the only way to go on long hard pulls. You don’t have the gear selection with power shift and they heat up. I disced firebreaks (no dozers bare ag Cats , for 35 years for the local government agencies. They had to change the contract specs to direct drive tractors only the power shifts couldn’t disc fast enough and would heat up. I can’t tell you how many contracts i had to takeover due to the agencies awarding low bidders with powershift transmissions .

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Tailseat, yea back on the 70’s 80’s and until the early 2000’s this time of year it was running those steel tractors 24/7, long slow pulls in a hurry to get everything ripped before the first big rain of the season and then it was time to park them for the winter and spring. Very different back then in our area lots of open ground that was ripped every fall and only a few concrete pipelines on the edges of the field. Not sure what they are saving on the replants now, another field about 5 miles to the south I saw all of the hoses rolled up and working everything in between, nice long straight 600’ pulls and very few turns IDK.