HELP! Fordson Dexta Stuck In Reverse

Title says it all. I was using the front grading blade, not under much load when my Dexta decided it was only going to go backwards. I could have swore I was in 1st Low and maybe I was shifting into neutral or reverse but was surprised when that was suddenly the only option. Well, high range/low range (or neutral) but as far as the main gear selection reverse only, I can move the lever and without the clutch there is some small amount of grinding. With the engine off I can move it to what feels like neutral but it's still in reverse.

Ideas :?

-Bernie

Not familiar with that exact model, but what you are describing sounds typical of the shifter has gotten out of track.

It is a matter of lifting the top plate off the transmission, and aligning all the shift gates back into neutral. When in neutral, all the gates (the slot the shifter ball hangs into) will be aligned straight across.

You may have to pry with a screw driver to align them. probably only the reverse is out of alignment. You will need to relieve any load on the transmission by holding the clutch down or rocking the tractor. Be sure it doesn't start rolling when it comes out of gear!

I have the rear of the tractor supported on jack stands right now. If I put it in gear (i.e. low/high range) and release the clutch the left tire spins. Apply the left brake and the right tire spins. So taking the load off shouldn't be a problem.

I have the shop manual and it gives detailed explanations of rebuilding the transmission but conveniently omits any mention of what order to remove/reinstall the gear shift levers and plate. It does show an exploded view. My fear is I'm going to do something wrong and drop a critical component down inside the transmission.

I did drain the transmission. According to the manual it's supposed to use W20 or W30 weight oil. What came out looked like the pervious owner had used some sort of hydraulic fluid instead.

Transmission Diag by Alden_Sloe, on Flickr
0902172041 by Alden_Sloe, on Flickr

That exploded view doesn't have the right item page for the selector lever parts. This view from the manual is a little better visualization:
Gearbox cutaway by Alden_Sloe, on Flickr
-Bernie

Wild guess here, but perhaps item 69 sheared off.
Those screws are all that moves those forks with
the shafts, it appears.

I just rebuilt a sherman combo, and had to pay
attention to those screws - in your picture, they look
almost the same as the ones in my sherman.

Just a guess - best if luck.

Steve@Advance is on the right track.

Sounds like it could be a common Dexta problem. The bottom ends of the shift levers wear off and can then slip out of position and between the forks.

Remove the 4 bolts holding the shift lever plate to the top of the transmission. Move the levers so that their bottoms will be in the proper position when the lever plate is lowered straight down onto the transmission.

Many years ago, I globbed weld metal on the bottoms of the levers, then ground them to a square shape, with rounded corners, that was too wide to fit between the fork gap.

Thanks guys! I'm feeling a little more confident about removing the shift plate. I found an old thread with some good info and pictures of what to expect on the inside:

http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=fordson&th=20346
Wayne in VA
Wayne's Dexta Page Procedure

I'll try tackling it in the morning and take some pictures. I guess it wouldn't be a shock that after 56 years the end of the shift lever might be worn :mrgreen: If so, before I practice my welding I'll invest in a replacement lever[/url].

-Bernie

Thanks guys! The advice to remove the top Gear Shift Plate and manually move the Reverse Selector Fork back to the neutral position was spot on. Seeing how this works internally what I suspect happened is I had the tractor in 1st gear and bumped the selector lever sideways. With the work end it was able to slip out of the outboard 1/2 gear selector fork and wedge in behind the other fork pushing it forward into the reverse position. I'm going to have to be extra careful until I can order a new selector lever.

In this first picture, taken from the right side of the tractor, you can see the shift fork closest to the center in the forward (i.e. reverse) position.

The box end of a Craftsman 5/8" combination wrench is just the right width to match the shift selector forks. This picture shows the neutral position:

Here's a picture of the end of the Main Selector Lever. It's about 3/8" at the top and tapers to about .310" at the end. The ridges must be from the original part? I can't see how that pattern could get worn into it:

It's difficult to tell from pictures of replacement levers what the end is supposed to look like but it certainly looks larger than the shaft above it:

Turns out this little learning episode may have be fortunate in that it prompted me to change the oil in the transmission. It looked low and when I drained it it had obvious signs of moisture and also appeared to be perhaps hydraulic fluid rather than the recommended straight W30 oil:

According to the Operator's Manual the transmission oil capacity should be 23 pints. I put in a full 3 gallons and
it is still a good inch or so below the oil level inspection plug :?:

I see that you?ve found the forum at Brian?s Fordson Tractor Pages.

It?s awfully rusty in there and the lever plate needs a gasket. One can be cut from thin cardboard like that of a breakfast cereal box, then a thin coat of non-hardening gasket sealer from the auto parts store on
each side.

Stranger things have occurred, but it seems highly unlikely that new levers can be found. Used will be about as old as what you have.

There?s a Fordson forum here at YT, in case you haven?t found it.
YT Fordson forum

(quoted from post at 01:34:03 09/04/17)
It's awfully rusty in there and the lever plate needs a gasket.

Click to expand...

It did look like there was remnants of a gasket. I scraped it clean and ran the tractor for almost three hours today and so far no sign of oil leakage. I'm not familiar with "non-hardening gasket sealer". I did consider running a thin bead of silicon.

it seems highly unlikely that new levers can be found.

Click to expand...

Reproduction main shift levers are commonly available. In fact the picture in my previous post is from the unit for sale by Yesterday's Tractors

The fluid that was in there makes it appear that everything is rusty. If you wipe it off or look at the wear spots it's not too bad. When mixed the fluid had the look of chocolate milk. Then after it sits it turns more translucent. There was some of the white tell tail signs of water in the fluid but not too bad.

That said, the brown color (colour) had to come from somewhere. Perhaps from the hydraulics that operate the front blade? Speaking of which, The Operator's Manual says the transmission should take 23 pints of fluid. I added 3 gallons (24 pints) and it's still an inch or two below the level of the inspection plug. Thinking about it, the hydraulic lines and cylinder that operates the front blade would need additional fluid. It's run from the transmission sump, right :?:
Except... the level was low before even starting the tractor and all three gallons of oil added can only be in the sump :!:

So, should I keep adding, likely a gallon or more, until the level comes up to the bottom of the inspection plug :?:

Another question, inquiring minds want to know, what is the purpose of the three spring loaded plungers that are compressed when you tighten down the selector lever plate :?: