TC55DA - EHSS clutch not engaging.

[Oldschoolmopar]

My TC55DA EHSS FWD/REV shifter was finicky and clutching made things worse. The root cause was an electronic switch for the shifter. Electronics are great when they work, a nightmare when you have intermittent issues.

Do you have a part number for that switch for the shifter?

 

[mikester]

Do you have a part number for that switch for the shifter?

Sorry no, that was 8+ years ago and I sold the machine to fund my M59. Try NH

 

[seankim]

Update:

I finally got the tractor fixed. Remember it just stopped moving and it's EHSS (TC55DA). I ordered all kinds of stuff to get it going fast and to keep from taking to the dealer. Bottom line.......I guess it was the Potentiometer. Here's what I did:

1. Put a new inching cable on and tried to adjust it to a good visible movement although I found that it should only move the EHSS control valve 2mm. (That's not much)

2. Put a new Potentiomet on. It still didn't move. I adjusted it every way possible and still.......no fix.

3. Read more and checked switches with a ohm/volt meter. The Shuttle shift checked out good, the Neutral 1-2 switch checked out good, even changed the EHSS Control module.....didn't fix it.

4. Put all old parts back on (now I just have the new cable and Potentiometer).

5. Adjusted inching cable to 2mm specs the best I could with naked eye.

6. Checked resistance to the switch on the EHSS control valve and it was good.

Started the tractor and IT IS FIXED!!!!!!

I'm going to order the Electrical Diagnostic tool for this tractor. It's approx $250 but I've done a ton of research/reading in the repair service manual and the Breakout
Box Part # 380001351 will make all this electrical EHSS diagnosis quicker and more accurate. The Potentiometer needs to put out 3.2 volts with the inching pedal depressed completely. The manual says to test this with a volt meter with the switch on, and black lead on Pin 11 and red on Pin 14 of the EHSS controller plug. Problem is......I couldn't figure out why and how this would work. If you unplug the harness from the controller, the Potentiometer has no hot lead to fire it to check it out!!! It gets it's hot into it from the Controller box. I could have plug it in and stuck into the wires but I didn't wanna start screwing with it like that. Anyway it's fixed and the digusting thing is I'm not exactly sure what did it!!!!

My tractor is going forward and back now. I replaced the cable and the potentiometer and now it works sort of. It is like I am dumping the clutch as I start off. Both forward or reverse. Suttle shifts just fine. I have had this tractor since it was new, no problems whatsoever. Now this has me perplexed. I do not want to just throw parts at it. The EHSS controller is pricey, 700.00 to 900.00. Any Ideas as to what might be causing my issues?

 

[seankim]

Well, this is an update. I replaced the Potentiometer and the cable relief valve from the inching peddle. At first, the tractor just jerked when the inching peddle was released. It was like dumping the clutch. I used the loader to raise both the front and rear tires off the ground. Placed jack stands under the tractor. I adjusted the cable to just barely activate the relief valve. To my amazement, it finally was working. The tractor now moved forward and reverse when the inching pedal was released. Just for giggles, I removed the cable from the inching peddle and started the tractor. The inching pedal worked just the same. So I do not really know what the relief valve really does. I reinstalled the cable to the inching pedal. I am so glad to have this tractor back in working order. So a recap. Replaced the cable to the relief valve, and the potentiometer. Adjusted the cable to just barely move the valve.