TC40D Cruise control

[jinman]

Take it from me, you DO NOT want to try and remove the operator's platform. I had no choice but to remove mine and it is a butt-kicker of a job. To aid you a bit, here is a photo of the magnet fully exposed. You can see the two bolts holding the magnet assy to the left of the donut shaped magnet. The second photo is with the big "B" shaped plate installed. Finally, here is an illustration of the pedal mechanism that shows an exploded view of the pedals assy and associated parts including the magnet assy. Also take note of the wires coming off the magnet and going to a connector about 8" up on a short pigtail attached to the magnet. If you MUST have more room to access the area. On the TC40D, if you remove the seat, there is a square port opening below the seat that will allow access to the top of the transmission case and let you reach in and disconnect the wires if you can't get to them from beneath the tractor. Removal of the seat is a whole bunch easier than taking off the operator platform.

 

[wrenchguy]

You say that you have had lots of experience changing these. Do they burn out often?

I worked at the plant where the tractor was built. I don't know if magnet failure is a very common problem for the customer but there were some at the plant that were weak or DOA.

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[jinman]

I don't know why your neighbor is selling his tractor, but with only 200 hours on a TC40D (not the later model TC40DA) that was built in 2003 or prior, his use must be more like a yard/barn ornament. 25 hours per year or an average of 2 hours per month doesn't make sense for ROI. It's no wonder he is selling the tractor. I have a TC45D with 1709 hours. My cruise control magnet works perfectly and has never been a problem. Like any other electrical device, some will fail while others never will. I don't think you have to worry about repeated problems. The magnet is just an electromagnet with no moving parts. I suppose the whole assy moves some as it is drawn toward the "B" shaped plate and could eventually have broken wires from fatigue where the pigtail enters the magnet donut.:confused3:

Also, New Holland has two HST filters. I wouldn't bother with getting the ruggedized one if you don't have a problem with the normal one. New Holland's HST filter is around $22 and the Wix replacement (Wix 51664) is about $9. I think if the Wix filters had a history of blowing out, they would not be selling them. I've never had my filter have any problem. I've used the std NH filter, but wouldn't hesitate to use the Wix if it were easy to get or the one I preferred. I think you will find that JD, Kubota, Massey, and any other brand sells their filters at a premium price. I don't think you can fault New Holland because of this.

In my opinion, if you are not doing primarily tillage work with your tractor, an HST is a big plus. For loader work and mowing where you change directions often, the HST will amaze you with its ease of operation. I've owned gear tractors and I now own a full size TLB with a shuttle shift. The HST is easier to use, plus the HST model has the tilt steering and better instrumentation along with several other deluxe features not found on the 12x12. If you wanted a 12x12, that would be fine, but I don't think you will regret buying the HST model.

 

[Notforhire]

Thank you all again for the additional info. The tractor is a 2002 and I don't know if the cruise ever worked. The owner passed away a couple of years ago, and his widow has decided to sell the tractor. They were part time residents, and mostly used it to bush hog a field. It was one of those machines that was there when he needed it, but he didn't need it often. That's why the low hrs.
It sounds like everyone is happy with the hydro, so that's good news. I do mostly loader work, and have a small field to bush hog. I think this unit should do the trick.

 

[barbqranch]

On the cruise control magnet, did you check the resistance? There are several things that could be wrong that won't require it being replaced. At least on my TC29D, the magnet not only has to get current and develop a magnetic field, it must be able to move over and touch the flag connected to the HST pedal. Also, if there is dirt between, it won't hold it, it has to touch pretty well to work.

 

[wrenchguy]

Just to be sure,when you press and release the cruise switch does the green light on the switch come on and stay on? Or does the light come on and immediately go off when you release the switch?

 

[Notforhire]

I haven't been able to unplug the magnet yet. I will check it out before I replace it, but at this point I'm pretty sure it's NG. The green light does stay on. If you apply the brakes it goes out. With the green light lit, I can stick a probe into the connector for the magnet and get 12v. With the coil on I can reach up and wobble it a bit, and it doesn't feel like it's trying to pull in any direction.
I don't own this tractor yet, so I don't want to tear into it too much. I mostly wanted to know what I was getting into. The only thing I'm not clear on is what the diode is for. Once I get the books and a wiring diagram maybe I will figure that out.

 

[jinman]

The diode is the "latch-in" path for the Cruise Control Relay when you press the Cruise Control Switch. The initial power to energize the relay comes from the Fuse #2 circuit, but the hold-in power and power to the magnet comes from Fuse #5 and is supplied through the diode. The diode isolates these two functions so that the proper timing is maintained to set cruise. If that diode is bad, cruise will try to set, but no power will be supplied to the magnet.

The cruise control magnet should be 11 to 12 ohms if read with an ohmeter. That means it normally pulls 1 amp of current when engaged. That's a pretty standard amount for the solenoids on our tractors. The fuel cutoff solenoid pulls 1 amp and the dual speed solenoid for the rabbit-turtle function of the transmission also pulls about 1 to 1.5 amps.

 

[Notforhire]

Thank you jinman. Before I remove the magnet, I will test it with an ohm meter. It would be a shame to remove it, only to find that it was not the problem.:ashamed:

 

[jinman]

If you get the magnet out, you should be able to hook it directly to a 12 volt battery to check it out. That's what the maintenance manual says to do, so don't worry about hooking it directly. If it frys, it was bad.