706 and 806 Questions

I'm looking at 706 and 806 tractors and I see frequent references in ads that either say:

- Torque Amplifier shot (or only works on one setting).
- Torque Amplifier rebuilt.
or...
- Torque Amplifier deleted.

I take it that the TA was a source of problems with these tractors?

So my questions:

1. If the TA is shot, how expensive of a fix is it generally? Just in general terms is this a major overhaul type of expense or what?

2. How can I test the TA to be sure it is working and working well? Are there signs that it is about to go out?

3. TA deleted? Is this even possible and is this good or very bad?

Many thanks.

Grouse

TA was ALWAYS an option. You could get any tractor IH built with a TA, without a TA.

Best way to check if the TA works properly is to load the tractor in say low 4th with TA ahead, with the
brakes, make the engine work, pull down to 2000 rpm from 2400 wide open, then pull the TA back and the
rpm should jump back to 2400 and tractor should not slow down, shake or shudder, stay right at the speed
proper for the rpm. More brake pressure should pull engine rpm down but no slippage of the TA.

TA was a great productivity enhancer. If an 806 has a TA it's worth it to keep the TA in adjustment and
keep it working. Leaman Tractor Parts does a very good TA rebuild for $1296.00, you have to remove the
center section and deliver or ship the TA to him. Others probably offer a similar service. So not really
even close to the cost of an engine rebuild. Many times the engine clutch and pto gears are replaced too
with the new TA.

Really hard to say how long a TA will last, once it starts slipping the end is near. But there are many
706/806 tractors that have over 20 year old TA's that still work fine. TA is ALWAYS having the right
gear, like a power shift without the horsepower loss. TA in the 706/806 does not freewheel like the early
TA's, but using it like a compression brake to slow down is the quickest way to kill one.

The IH TA in large frame tractors is a hydraulic clutch operated speed reducer in front of the transmission. A front clutch (not the main tractor clutch) locks the TA gears into a
rotating mass that drives the trans at 1:1 direct from the engine. It must have MCV (multiple Control Valve) pressure applied to lock that multi plate clutch. That clutch is
released when the lever is pulled back, and the YA assembly reduces the drive speed (about 1/3 reduction). The assembly tries to rotate backwards in its housing but is restrained
by a sprag clutch that allows rotation in the engine direction only. When the TA unit is thus stopped, the gears drive through it in reduction. To assure the tractor will not
coast down hills and become uncontrolled, there is a second (less powerful) clutch that is now engaged that keeps the sprag clutch from rotating in its allowed direction. This
clutch is not designed to take engine power, only to prevent down hill free wheeling. The MCV pump and valving are responsible for steering and brake application boost as well as
master clutch pedal assist (on some models). Common problems happen when the TA is abused by trying to use it as a brake to slow down for road speed turns, or if components wear
and fail from long use. TAs are wonderful and an important advantage for tractor applications such as bailing chopping and tillage. I have never had one fail, nor have neighbors.
Servicing and adjustments ov the controls and MCV are normal maintenance. Jim

Ya want to test a HYD T/A ya don't do it in LOW 4 as they will lie to you in low 4 or even high 1 and 2 . Ya want to test then get it out in high 3 or 4 flat out and stand on te brakes and drag her down hard then with your left foot on stand by on the clutch pedal just incase she stops dead in her tracks you shove the clutch down as at times even when the stop it may grab and things get ugly fast if it does grab That will tell ya . I remember one 826 that i bought at a sale under the 100% ride and drive , drove it around the sale lot a bit and played with the T/A there and due to the crowd i was unable to REALLY test it and loaded that tractor and brought it home . Once home i took her down the road to the grange hall and came back UP the hill in high forth wide open and started to load her on the brakes and pulled the handle and she stopped dead in her tracks , but in low she hit everytime . Called the auction lot and talked to the owner and he said stuff a T/A in it and send me the bill , I'll take that off the guys check for lieing to me about a good T/A . So i did just that 600 bucks for T/A 475 labor and i ate the clutch and pressure plate and IDPTO shaft and bearing .

There is a lot mor to look at other then a T/A , and yes they do fail over time . How often ?? i know the ones i have installed have well outlasted warranty BY YEARS . the one i installed in my one friends tractor is just now starting to go and if Eugene can get 25 plus years out of one I would say they hold up pretty good . My personal 806 that i have had since 1998 is still going strong . I worry about the engine more then a T/A and tires , you priced TIRES lately ??

As far as TA deleted as Evil says that was an option so it could be bought with out. Which I think a tractors with a factory TA delete are way lower production numbers than those so equipped. The serial number would have an S suffix to denote it being equipped with a TA. ....or at least that was the case up to the point of the mfg of the 660. There are also manufacturer that produce TA delete shafts. Installing such a shaft removes the TA clutch and planetary gears and the one way sprag.