Fordson Dexta Gear Problems

I have a 1959 Dexta and it doesn't like to go into reverse most times. It also gets stuck in 1st gear. Is there any easy way to fix this? I believe the clutch is good I think it maybe more of a shifter lever problem? Any help would be appreciated!

Thanks! :D
 
There is a very high probability that you have a worn ball on the gear shift. This is quite common. The end is shaped like a lollipop with the top sheared off and fits in the slot of the channel shifting forks. I have three Dextas I am working on and all three have severely worn lollipops. They had been welded up before and ground back down to fit, but I don't think people knew the correct dimensions or they had worn down again. You can purchase a new shift lever at many places if you don't want to rebuilt the old shift lever. I bought a new one and it fit perfectly. Just remove the bolts holding the cover plate and you can easily remove the entire shift and range lever assembly.

The only difficulty will be removing and reinstalling the retaining circlip and tensioning spring on the shift lever. If you are good at welding you can build the ball up and grind it without removing the shift lever assembly.
 
You will also find out that the edit function on the forums does not work so you have to proof read your posts before you post them. Otherwise you have to correct any errors or additions in a subsequent post.

I should have said in the previous post. The sift lever ball or lollipop can be welded without removing it from the gear shift plate, but be sure to cover the components with a cloth or foil to prevent grinding abrasive from contaminating everything. Also note that the lollipop ball is very hard steel.
 
Thank you very much!!! Do you know of where I could get rough dimensions of what size the "lollipop" needs to be? Or does it just need to be ground to fit?
 
I am recalling this from memory so it may be incorrect. I think the radius profile before grinding is a 1/2 inch diameter cylinder 1/2 inch wide. The departure line runs through the axis. The only way I can be sure is to take the shift plate off and measure it. I am not sure I have the time in the next couple of days.

Another dimension that needs to determined is the length of the shift lever below the plate This dimension should also consider the thickness of the gasket. The length should be so that the shift lever has freedom of movement and does not normally bind or press down on the shifter fork channels. This will allow for some manually applied downward pressure by operator. I will have to verify the previous statement.
 
Okay! That gives me rough enough dimensions that I can see how far off the lever on mine is! And as far as gasket goes this ol' girl has probably been missing hers for many years! Another thing to fix! :p
 
Tractor Guru,

Tomorrow I may be able to take pictures of what I am about to talk about. As it is said one picture worth thousand words so you may want to wait rather than puzzle over my verbal explanation. I have never posted a pic here so cross your fingers.

I removed the gear shift plate and measured the lollipop. It does approximate a ball of diameter .500 inch. The parallel slab sides are not .500 inches, but are 0.370 inch across.

I told you that the top is ground flat, but it is not quite half the half inch diameter of the projected sphere. Instead it is best to imagine grinding down the ball until the mesa or flat part has a diameter of 0.45 inch. This is measured using the what remains of the circle after the sides are ground flat or you can grind the flats later.

The distance from the the shift lever mesa to the bottom of the shift plate is pretty close to 2.00 inches.
 
I have a good reason for taking pictures of this lollipop as I call it.
I looked all over the internet a year ago trying to get a clear close up image of the original shape. The images I found were worn weld ups based on descriptions similar to the story of the seven blind men describing an elephant each had felt. lol
 
Tractor Guru

Well here goes.


mvphoto7135.jpg

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That is why I photographed it. I probably spent at least an hour and a half on the internet trying to find a picture and measurements of a new one. I could not tell the exact shape and dimensions of an original one from books or vendors. I have O1 tool steel so I will probably turn the lollipops to size and then harden them. I have to figure the right profile to pin them on the shafts so they won't break. I wouldn't want pieces to get into the gears.
 
This was very helpful.My Dexta gets stuck in gear from time to time, usually at the worst possible time. I keep a 1/2" wrench in the tool box
to take the cover off and put it back in neutral. Maybe I will buy a new shifter.
 
Okay! So the worn shifter fix tightened the shifting up ALOT but didn't fix the stuck in gear problem! Then I noticed the "dowels" in the
case that are spring loaded (Pictured) Only one of them is up and the other two are stuck! Does that have to do something with it?
a250029.jpg
 
(quoted from post at 22:31:53 12/10/17) Okay! So the worn shifter fix tightened the shifting up ALOT but didn't fix the stuck in gear problem! Then I noticed the "dowels" in the
case that are spring loaded (Pictured) Only one of them is up and the other two are stuck! Does that have to do something with it?
a250029.jpg

Guru,

Before you try anything if you can run the tractor with the range shifter in neutral crank it with the fuel cock closed and after it stops pull the stop lever out and leave it out if it will stay. You don't want it to accidentally crank while you are working on it. If necessary crack open the injector line nuts to make sure there is no fuel going to them.


I don't quite understand what you mean when you said the repaired shifter tighened the shifting up, but it is still stuck in gear. I need a more complete description of what is going on. Can you move the shifter in all four positions with the right range shifter in neutral or high or low?

Have you rocked the tractor back and forth with the range shifter in high or low and then tried the left hand shifter? I will have to check the Dexta with the shift cover that is off when it is not as cold and rainy. The rain quit, but it is still wet and co-cccooold. Looks cold and snowy where you are.
 
I will try to explain the best about what it is doing! When I'm driving the tractor in 1st and I go to shift into 3rd or reverse the tractor
seems like it goes into the gear, but if you let out the clutch the tractor will stall! If you put the lever into the "neutral" position the
tractor will still drive in 1st! You have to shift to 2nd, and sometimes even 3rd before the tractor will go into reverse and reverse
actually function! So basically you have to shift through all of the gears most times before it will actually hit reverse.
 
It sounds like when you shift it is trying to mesh two gears at the same time which is why it stalls the engine when you let the clutch out. It could be that the lollipop is too wide.
I will have to look at this.

I kind of feel like the ground based NASA lab trying to duplicate a problem in space to find the problem.

I haven't got a swimming pool to simulate the weightless environment. lol

Someone else may be able to reveal the problem from prior experience before I get a chance to evaluate everything.

.
 
I have a manual of the transmission which is available as a free download at
fordson-dexta.de

There are several sections to this. You will want to download just the manual section pertaining to the tranny and rear axle. I don't remember which one it is, I think it is still available.

Make sure you have your antivirus updated. There is always some clown trying to ride a virus or trojan in on some of these.

The three dowels are spring loaded plungers each with a ball on the bottom. A broken spring or rusted plunger might cause the problem. I believe the balls fit into recesses in the shifter rods and rise up and down in a ballet as the rods are moved.

I also think there are four selector forks and two selector rail gates. The two gates are the parts that the lollipop directly contacts Each of these forks and gates have a retaining screw and locknut. If one or several are loose or broken this might add to the problem.
 
I found the pdf file by typing in Dexta gearbox and search.

It will come up www.fordson.se/6_8_Dexta_verkstadshandbok_101-198.pdf

That is the one you want.
 
Guru,

"Peccavi".

This was the one latin word message supposedly send by Charles James Napier to his superiors in India (1843) when he retook the province of Sindh instead of just putting down rebelling troops. It translates to "I have sinned".

Well so have I. When I put in the new shift lever I did not go back and seal the shift plate so some water entered the tranny. This is nothing new, but I should have remembered to reseal the cover.

If your Dexta has been outside during a lot of rain it too many have water which may have wet the shifting rods and gates.

You need to test the gates with a long flat bladed screw driver.
Test the left hand gate first. It should slide forward until the spring loaded ball enters the detent cut into the shift rod. The same thing should happen when you lever the gate to the rear to shift it to reverse. If you do not feel a positive click at each point then the ball is not entering the divot or detents or has no pressure on it for some reason.
The same thing should occur when you lever the right hand gate and the range shifter.

You should not be able to move both gates together at the same time or if one gate is engaged in a gear you should not be able to move the other gate from the neutral/centered position.
You might want to take an oil gun and lubricate the gates and rods or any other part that might have rust on it.

If you need photos I cannot do it today.
 
Okay thanks! I'll go out there and feel everything and oil what needs it! I don't imagine I will need pictures, but thanks for offering!!!
 
I have reread you description of the problem. You may have a loose shifting fork. If it still drives after you put it in neutral and it is still in first gear this is very likely. When you shift to other gears it slides the loose gear temporarily back into position. There is a very high probability this is the problem. Your may also be able to feel the loose gear or the fork moving when you move the selector rail gates if this is the problem.

I am not sure what happens if one of the slide gates is loose and will have to look myself. I think the check for this to measure the distance each gate is from center at each position. If the gates don't stop at the same distance something is wrong.
 

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