300 TA and Tranny Again

I asked before about the T/A being out of adjustment if it could cause shifting problems and was told no. I have read other threads and they were told that if it was running and would not free wheel while the clutch was down, then the T/A was out of adjustment. At the time my 300 was not running and I could not really verify this, I now have it running and it most definitely will not free wheel while in gear with the clutch disengaged.

Can someone please point me in the right direction with some plain English advice? Thanks!

A TA that is not adjusted properly will cause shafting problems. The TA contains a one way clutch that, along with the TA clutch, will keep the transmission input shaft from turning backwards. When you release the main clutch, if the tractor starts to go in the opposite direction, the TA will hold pressure on the transmission gears making it hard to shift. When the TA clutch is released the transmission input shaft is now allowed to rotate in the opposite direction releasing the pressure from the gears to allow them to be shifted.

A correctly adjusted clutch and TA will have the correct free travel on both clutch release bearings so that they are not turning when the clutches are released bu yet allow total release when necessary. The adjustment on the link connecting the two clutch release levers is critical to assure proper operation. The main clutch needs to be completely released before the TA clutch is released. When engaging the clutch the TA clutch must be fully engaged before the main clutch engages. These engagement points must be very close together but must happen in the correct order.

As far as free wheeling, with the TA lever pulled back the tractor should free wheel going down hill. This is because of the one way clutch in the TA. In the direct or forward position the TA clutch is also engaged and the tractor should not free wheel.

A properly operating TA should not free when when in direct drive. When pulling the TA lever is should move a couple of inches and then get harder to pull as the bearing engages the levers on the TA clutch pressure plate assembly. Before the lever is all the way back to engage the latch, that TA should down shift and the tractor will be able to free wheel. To check the adjustment link between the clutches face the tractor slightly uphill in first gear, TA lever forward. Slowly push in the main clutch. When the tractor stops, it should stay in place without rolling backwards. Pushing the clutch in a little more should allow the tractor to roll backwards. Releasing the clutch, the tractor should stop rolling backwards before it starts to move forward. If, when releasing the clutch, the tractor starts to move forward and then does an upshift as the TA engages, the connecting link is out of adjustment.

An out of adjustment TA can cause shifting problems. Often if you can't get it out of gear, pulling the lever back will allow you to shift. Loose linkage can cause problems also, both the external rods, etc, and inside the clutch housing. It has to be adjusted by the manual (but if everything is sloppy, you have to try different things to adjust it) --too long for me to post here, maybe someone else will, but you need the I&T or IH manual. What that procedure does is make the TA clutch disengage about the time the main clutch disengages. Loose linkage makes it next to impossible to adjust correctly, it will cause excess gear clash when shifting. It will free wheel with the lever back going down hill. The best test to see if it is working right is to use it under load, if it slips with the lever back, it is either out of adjustment or needs to be overhauled. If you do not have a way to put it under load, put it in 4th (does not need to be full throttle) pull the TA back and push hard on the brakes, the tractor should slow down and possibly kill the engine. That's plain english, I have to leave the complicated stuff for someone who knows.

Owen, you posted while I was typing -- yours is a more complete answer than mine.

The clutch pedal on a TA tractor works on two clutches. The master clutch (on the engine"s flywheel where you expect it), and a TA clutch. This clutch is 1/3 smaller but is similar in construction. It faces backwards and is mounted on the TA rotating parts. With the lever forward (direct) the following is a general description:

As the pedal is pushed down, the master clutch releases first(disengaged, no power through it). In about 3/4 of an inch or so farther, the TA clutch is released. From that point on down to the stop, both are not transmitting power.

If the TA is forward (direct drive to the trans)
The TA clutch engages as the clutch is let up.
This locks the TA reduction gears together, and causes the TA unit to spin in the direction of the engine rotation. As the clutch is released farther the master clutch engages, moving the tractor if it is in gear.

With the TA back (reduction), the TA clutch is held in released position by the linkage and its throwout bearing. The pedal will only operate the master clutch. When it is engaged (TA back) the TA input shaft rotates. Because the TA clutch is released, the gears operate. The reduction tries to spin the TA housing backwards while the gears try to turn the TAs output shaft forward. The TA housing is prevented from turning backward by a sprague (one way clutch) this allows the TA planetary gears to drive the TA output shaft forward, but in reduction.

Moving from reduction to direct: As the operator rapidly moves the lever forward (the only way to move it in or out of TA) the TA clutch is engaged, locking the gears together as a unit, and causing them to spin as a unit in the forward direction. The sprague clutch spins free in this direction.

Moving from direct to reduction, the TA clutch is released. The gears in the TA now are free and the housing stops spinning forward, and is restrained from turning backwards due to the sprague.

For the same reason we do not ride the clutch in a truck or car with a manual gear box, we do not slowly move the TA lever in and out of direct.

If the TA clutch is not completely disengaging when the ta in back, or when the clutch pedal is down all the way, the ta clutch will drag. This drag will prevent easy shifting of the trans when the tractor is on a hill going up forward, in forward gears, or going up a hill backing in reverse. This is because the tractor is hanging with pressure on the trans gears that are trying to turn the sprague the wrong way (which it will not do). This pressure on the teeth is what makes it had to shift out of gear.

A TA that is way out of adjustment can refuse to go into reduction, and will stay in direct (it might slip under load, but it is heating and will fail in that condition. A TA with a its clutch out will only have reduction and no Direct.

A TA with its sprague clutch out will have only direct, and when the TA is pulled back the TA unit will turn backwards and the tractor will appear to be in Neutral.

A failing TA sprague will sometimes work and other times not. Or it will fail under load stopping the tractor.

The tractor should be controlled so that at no time is the tractor moving faster in TA than it would in direct in that gear. The TA would then be over speeding and it is not good practice.

The tractor should free wheel in any gear in the direction of that gear with the TA back.

I hope I covered what you needed. Jim

We did well and agree!!! Jim

The following instructions from the archives helped me lots as my linkage was worn.
by Owen Aaland

03-15-2009 14:32:22

On a mechanical TA there are three adjustments you need to get correct.

1) free travel on the engine clutch

2) free travel on the TA clutch

3) the TA clutch shaft must move as soon as either the engine clutch pedal or the TA clutch lever is moved

To adjust the linkage start by disconnecting the main clutch linkage pin at the clutch shaft. Remove the interconnecting link and spring between the engine clutch shaft and TA clutch shaft.

Adjust the TA clutch linkage so that with the lever ahead and the pin in the slotted hole, the pin will move 3/16 on an inch between the front of the slot and the point where the release bearing contacts the levers on the clutch pressure plate. Hold the pin to the rear to compensate for worn pin and hole when making this measurement. That takes care of the first adjustment.

The next step is to set the engine clutch free travel. Hold the bottom of the clutch to the rear and adjust until you have an inch of free travel on the pedal. Holding the lever to the rear will compensate for worn pin and hole.

The last step is to connect the spring between the engine clutch shaft and the TA clutch shaft. Adjust the connecting link as short as possible without moving either shaft while inserting the pins.

Check the adjustment by watching the TA clutch shaft as you move either the engine clutch pedal or the TA lever. The TA clutch shaft should move as soon as either lever is moved.

Dynamic testing can be done by driving the front of the tractor up hill. With the TA ahead and the tractor in a forward gear, the engine clutch should should release about have way down. About 3/4 of the way down the TA clutch should release and the tractor begin to roll backward. This will ensure that the TA clutch engages before the engine clutch. If it does not engage first you will get a double shift when you release the clutch.

CNKS your theory on putting it in 4th gear and holding the brakes doesn"t always tell if the TA is working properly. I have a 400 in my garage now that im putting back together that the TA wasn"t working. When I bought it I did the same thing you said and it killed the motor. Found out later that the TA lever was back but it wasn"t going in low range, it was staying in high range. Best way to test it is go up a hill and shift to low range and you can hear it shift. My problem was found to be the fingers on the TA pressure plate weren"t adjusted properly.
Hope this helps

It is easy to tell if the TA slows the tractor. I had a working TA and this method was used in the absence of a load. It did not slip. I have not used it under heavy load, as I have 5 acres and no implements except a bush hog, blade and sprayer (and 8 tractors).

This is great info! I can't get my 340 Farmall to shift into neutral with the Lever forward and parked on an incline. This is the best thread to date imo that properly explains what to look for and to adjust.

Get an owner's manual and/or I&T manual for your tractor.

Just adjusting the TA willy-nilly is a good way to get things totally screwed up.

The guy that had my Dad's W400 previously had the TA so far out of adjustment that it was in TA *all* *the* *time* and wore the TA clutch down to the nubs.

There will be measurements in the book to get you in the ballpark. Sometimes with worn linkage you'll need to fudge the measurements slightly, but not that much.