Explain the TA on a Farmall to me

Bobl1958

Well-known Member
I have a little 340 Farmall that we just finished the engine overhaul on. I bought the tractor with a stuck engine because it was such a straight tractor. I gambeled on the rest of the tractor because it was so straight. New sleeves and pistons, and carb overhaul and it runs like a watch. Lpto works like it should, even the tachworks.
My question is about the TA. It appears t work, but have not tried under any kind of load. What is the purpose, and do you drive it in direct, or TA? Do you start in direct, or TA? How is it supposed to be operated? Thanks for any help. I have all the manuals. Bob
 
If your just driving around I'd leave the TA in the high side so it doesn't freewheel downhill. TA is for heavier pulling like when plowing up clay hillsides or disking up hills. Soon as you get up to the top of the hill shift the TA back to the high side.
The TA is a great productivity booster, Dad had a '54 Super M-TA and a '57 450 both with TA. We had quite a few hills I used it on and even pulled the TA to the low side when turning on headlands. As a general rule you don't want to normally run in the low side of the TA but if it's bush-hogging tall weeds or grass in just a small area go ahead and run in the low side. Dad ran in the low side when combining oats that had blown down just days before they were fit to combine with our Deere #25 or #30 combines.
 
I am an owner for its entire life of a Utility 350. It still has its original TA and not been apart for that. Proper understanding is a good idea. Here is my rendition:
The TA is placed in front of the transmission, and behind the engine. It is a direct drive, or reduction drive of about 30%. The result is 10 speeds forward and 2 reverse. The transmission in yours is a derivative of the ones used in and H or 3XX tractor.
In direct drive the entire TA unit rotates as one, and at the same speed as the engine When the engine clutch is driving. This direct drive is caused by a smaller clutch (called the TA direct clutch in this description). It causes the TA gears to be locked up. (it is a planetary gear set, if any of the elements are locked together it cannot operate).
When the Lever is pulled rearward, the TA direct clutch is released (not engaged, not driving) the internal planetary gears in the TA unit are free to spin. The reduction motion and power now tries to spin the TA gear housing backward. The housing is not allowed to do this by the incorporation of a one way sprag clutch that allows rotation like the engine, but prevents rotation the opposite way. Because it is restricted from turning backwards, the internal gears drive the output shaft into the transmission (at reduction) causing slower than engine RPM into the transmission.
Factors:
1} The tractor will coast freely down hill faster than intended for that gear selection in the trans. No engine breaking. This is to be avoided because it is dangerous to go down hills with the vehicle in neutral, relying only on the brakes. It also would allow the TA unit to be spun to much higher than design if allowed to coast fast.
2} The TA is designed to be used when needed and basically seen as normal operation in either direct, or reduction. (others will argue this but the fact is there is wearing parts in both direct and reduction.
3} The clutch and Sprague system do not like slow lever movement or riding lever. The lever is used like a switch, It is moved as rapidly rearward, or forward as hand movement allows.
4} used in road gear (5th), the TA back gives a nice way to get up to medium speeds then shifting the handle forward into direct for cruising. This really saves the engine clutch wear because starting from a dead stop in 5th direct requires slipping the clutch. Using the TA eliminates this to a great extent.
5} It is lubricated by transmission oil (Hytran) and is not a separate chamber.
6} The reduction in the tillage gears is similar to changing to a lower or taller gear when moved. this allows the engine to avoid bogging down when encountering a tough spot in the field. When the load decreases, putting the lever forward brings the speed back up. When operating a baler or other pull type implement, the TA can allow slowing as needed without reducing PTO speed.
In general use it as needed to select a good speed while keeping engine speed where needed.

Please Use the PTO at full speed, PTO equipment run slow will reduce effecticeness and cause excess stress. Jim
 
Hi/low powershift. Splits any gear. Main porpous is to eliminate the need to downshift in hard spots when plowing. Also works good for baleing when you hit a heavier windrow.Mainly run in direct. Start in direct. However,sometimes you can start out in TA in road gear in more difficult. Do NOT use as a 'jake brake' to slown down from road gear.Doing so will destroy the TA. Shift hard and fast. Slow easy shifting destroys the TA clutches. Call me Bob for more info.
 
Thanks to all for your great replies. I drove a 1066 for a farmer who was behind when I was 16, but couldn't remember what he told me or how I ran it. Course thatwas 50 years ago...lol! I knew TA's were usually out, meaning use or abuse, and want to treat this one correctly. It won't do much beside rake or pull the manure spreader probably. Thanks again.
 
(quoted from post at 16:37:08 12/18/23) By high side, do you mean direct?

You do your homework, calling the speeds by their proper names!

Yes, high = direct (DD), and low = TA.

To answer your questions: Yes. Yes you drive in direct or TA. Yes you start out in direct or TA. Same as choosing any of the five main gears, you select for conditions and how fast you want to go. The only exception is going downhill. You want to be in direct unless you are pulling a plow or something else that would hold you back on a hill rather than push you. Otherwise, you are going for a RIDE!

To shift into TA, you grab the handle with your fingertips and pull the lever until it latches back. To shift into DD, you squeeze the trigger with your thumb to release the latch and let the handle ahead. Doesn't have to be a particular speed. If you feel stupid with how fast or how slowly you're moving the lever, you're probably doing it wrong. It should just be a natural motion.

This post was edited by BarnyardEngineering on 12/19/2023 at 03:49 am.
 
Great info here. TA's for me make the tractor more valuable. All the bad rap they get is from operators that abuse them, far as I'm concerned. Ive had the smaller TA in the 450, 656, and the large frame tractors,806,966,986 and 1586 and never had a TA issue. The 806 (wish I didn't sell it) had over 11,000 hours when it left the farm and original TA. Maintenance and keeping things adjusted can go along way
 
If you think about it, the logic that you should not use the TA because you'll wear it out, or avoid tractors with TAs because they wear out, is silly.

By the same logic you should avoid running the engine, or avoid tractors with engines, because you'll wear them out.
 
Nice freature for a lot of task using your tractor . Never had to do anything to ours( 50 years) just review the operating in the manual and I T manual for setting levers and hand lever
 
Do you have an I&T service manual? It has a good explanation of the TA and its adjustments. Never ran one myself but I have an Oliver with hydra-power which is about the same thing. Nice feature to have.
 

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