T/A

It seems like lots of your tractors have a torque amplifier addition to the transmission which if Im correct give more gear ratios and allows on the move gear change, is this the case. What I want to know is what happens to a tractor that develps a T/A issue, will it still drive but with less gear or what? How difficult are they to fix? Just some general thoughts would be useful.
Thanks
Bill

Bill, the Torque Amplifier was a product of International Harvester. It allows a selection of two speeds in each gear without clutching. There are several different types depending on the model of tractor. Do you have a particular model in mind? Some are a much greater problem than others when things go wrong.

I don't know much about the things either, but will TRY. They do give more "gears" by changing the way the power moves between the engine and trans, not necessarily with actual gears. When used you lose ground speed but gain torque(pull power in other terms); hence the name Torque Amplifier. From what I understand you can still drive, but you will lose some of the drive or it will freewheel(no holdback/drive from engine, especially on hills) at times.Usually low(T/A) side goes out, leaving direct drive(high range) intact(from what I think I remember reading on here).

For fixing depends on make and model for getting at it. Just replace the T/A in a Farmall 706. It started as a annoying jerk(likely from the hydraulic valve unit found on this model), then it got to the point it would barely pull itself and a small round baler up hill and no resistance going down(had to ride breaks heavy). Had to strip entire front side of the transmission to bare cast. That required splitting the tractor into three main pieces(front/engine, torque tube(front trans), rear trans/diff), with stripping it down so far to that(hoods, tank, steering pedestal, and so on). I never had a T/A unit apart to say what's inside, likely a very complicated mess of springs, bearings, levers.....

Hope it helps some and that someone that knows more chimes in, even to correct me.

And most trouble is caused by operator unintentional abuse

Depends on the make, Bill. Early IH T/As used a mechanical clutch, planetary gear and a roller clutch. Oliver HP used a hydraulic actuated clutch with countershaft and a sprag clutch. Those are the two I know something about. Different systems to do the same thing.

The work about like a Multi Power on a Massy.

I do some custom worjork with a friend who has 2 806 and a 1066. only the one 806 has a torque. The one that doesnt has been played with and in my opinion the more you play with an ih the faster the torque goes.
Ford if you are looking at the differnt types of makes of tractors that had them that i know of are massey with multi power , I have a ford 7700 with dual power, ih with the t/a, and i believe oliver had something but not for sure

IH in Great Britain sold TA in 1966/67/68 as optional extra on the model 434, a dash mounted lever than gave an lower speed in each gear hydraulically. without using the clutch. Unlike the MF Multi-Power, IH's system gave full engine braking in each gear.

When it was new it was a good system, but they did fail in use after a short time. Most were locked in either the slower or the faster gear; too expensive to economic repair.

Later IH GB fitted TA to some 84/86 Series but they too suffered from same problems.

(quoted from post at 22:04:38 04/22/15) The work about like a Multi Power on a Massy.

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I'll add to the list as Ford has Dual-Power & JD has hyd hi-lo. Sometime when the hyd 2 speed fails one loses one speed and sometimes one loses all speeds. Usually but not always the tractor must split to repair the problem

(quoted from post at 05:52:15 04/23/15)

(quoted from post at 22:04:38 04/22/15) The work about like a Multi Power on a Massy.

Click to expand...

I'll add to the list as Ford has Dual-Power & JD has hyd hi-lo. Sometime when the hyd 2 speed fails one loses one speed and sometimes one loses all speeds. Usually but not always the tractor must split to repair the problem

Click to expand...

Over here the Ford Dual Power has been a very reliable system. Unlike their earlier Select-o-Speed :roll:

Remember Ford's later column gear change system? They were named Guess-a-Gear because until you engaged the clutch it was uncertain which gear you had selected :lol:

The Allis D series high/low that could be shifted on the go I liked the best of all those types from that era and gave less trouble than most others. The Farmall TA system I liked the least.