TN60A NH Tractor with 16x16 EHSS issues...

[SBParks]

Hello fellow NH owners,

I own a NH TN60A FWD with the 16x16 EHSS transmission. The tractor has the 32LC loader and the 759C backhoe. I use the tractor around my property for light work - Mostly brush cutting with the Landpride 72" brush cutter.

The tractor was purchased new in the summer of 2005.

At 150 hours of operation at the start of last season (early 2008), the tractor would no longer move... engine running, range and gear selectors firmly in place, clutch pedal out, operator on seat, forward/reverse lever either direction... No movement from tractor. Normally, I would hear a small 'click' noise after moving the direction lever in either direction... an indication that the transmission was engaged, then the tractor would move. Now, No 'click', no movement.

I had no choice, but to transport the tractor to my local NH dealer/service shop where the tractor was diagnosed with a faulty (bad) trasmission control module (part # 87575340). The part was replaced and all was well.

Now, working with the tractor this season at 200 hours of operation, the tractor, although not disabled, is showing some signs of the same trasmission problem. After working for roughly an hour or so, the tractor will decide not to move, forward or reverse. An attempt to put power to the wheels occurs (a soft movement), then, no movement. Fwd/Rev level still in position (didn't jump to center).

I am concerned that I'll soon be back in the same predicament.

One thing I am noticing is that prior to the first incident, the transmission status lamp would flash a trouble code. I don't remember what it was. I can't say I've ever seen the same status indicator flash out a trouble code since the tractor was in the shop the last time.

Any suggestions as what to do with this? My first work *was not* covered under warrant even with the small number of hours on the tractor.

Am I looking at another transmission control module replacement? Is this something that I could replace or is there more to this than just replacing the appropriate part.

I certainly would appreciate some insight to my problem from this community.


Thanks, Scott
Souther Tier of New York
New Holland TN60A with the 16x16 EHSS Transmission

 

[RickB]

First, let me say I can only suggest what may be wrong, it's impossible to tell for sure from here. The most likely cause for an intermittent no-move condition without an active fault code on a tractor of that age would be a faulty transmission presure switch. The switch is failing, the ECU reads no (or low) regulated pressure at the trans control valve, and refuses to engage a clutchpack. 87395493 is the part number. If you have never replaced this switch, you should remove the left rear tire and wheel to access the trans valve.

 

[SBParks]

Rick,

Thanks for the suggestion. No one, so far, has suggested anything other than the ECU at this point.

The dealer, originally, had me checking the switches that confirm that the tractor is in a Range and in a Gear. I took these switches out and confirmed that they work correctly.

I wish I could remember the code that it was flashing to me before the first failure, but I didn't document it anywhere. Definitely, no codes this time, but I'll be watching to see if I get any.

Taking the left rear wheel off to access the transmission pressure switch... What would I be looking for... Where is the switch? Once the wheel is off, where do I go from that point?

Thanks for the discussion.

Scott

 

[RickB]

There are three 10MM bolts with nuts to be removed along with the inner fender extenssion panel they attach. The pressure switch is in the transmission control valve housing. It has two individual wires in separate female spade connectors, not weatherproof connectors. The switch is oriented paralled with the rear axle towards the top of the valve body. A new switch will have identical threads and connectors, but possibly a different shape to the switch body, depending on whether you have the old style switch factory fitted (you should have the older style switch IIRC). If you have a rocker switch controlling your MFD clutch, there is another of these same switches in the services valve contolling the MFD dash icon. The services valve is ahead of and a little above the transmission control valve.

 

[SBParks]

An update to this issue that may spawn a few more ideas...

I was using the tractor last night to do some light loader work as I needed to help a neighbor with a construction project. We were backfilling the foundation for an addition to his home.

So, I was in the process of moving the tractor back and forth to scoop some fill and to move it to fill in around the foundation.

No problem moving the tractor back and forth for the 90 minutes that I was working on the job. I did notice, however, that a different symbol (icon) in the dash panel was being lighted. This one was the red circle with the exclaimation point (!) inside of it that is close to the parking brake indicator. Funny thing was that it was not fully lighted, it was blinking (stuttering) as if it had a bad connection or if whatever controls that lamp could decide whether to light it or not.

I can't say I've seen that indication before. I did shut the tractor down, restart it and after a while, the icon was no longer on.

Do you know what the meaning of this waning lamp is and if it may be associated with the transmission issues that I asked about earlier?

Again, no trouble codes were flashed to me during operation, however, I did see the transmission error lamp (yellow gear) after performing a shift out of sequence. This lamp went out as soon as I correctly made my shift.

Any help or ideas are appreciated.

Thanks, Scott

 

[RickB]

Your brake oil reservoir needs to be topped off. Use only genuine New Holland hydraulic brake oil. A quart bottle will last you years and years unless you have a leak of some kind. This info is readily available in the operator's manual.

 

[Larry-On-The-Hilltop]

Scott,

There were also problems with the actual forward/reverse lever (switch) that's mounted to the steering wheel on these tractors. 'Improving' that switch was one of the major highlights in the release literature for the T4000 series tractors. I had one die on a TN60A with the 16x16 Synchro Command transmission at ~200 hours on the tractor that NH ended up buying back under warranty. I'd try changing that first before I started tearing everything else apart. My current TN60A is working much better (so far!) than the first lemon NH sold me. Hope this helps. By the way, what part of the Southern Tier are you in? I'm just south of Broome County...

Cheers,
Larry

 

[RickB]

Scott,

There were also problems with the actual forward/reverse lever (switch) that's mounted to the steering wheel on these tractors. 'Improving' that switch was one of the major highlights in the release literature for the T4000 series tractors. I had one die on a TN60A with the 16x16 Synchro Command transmission at ~200 hours on the tractor that NH ended up buying back under warranty. I'd try changing that first before I started tearing everything else apart. My current TN60A is working much better (so far!) than the first lemon NH sold me. Hope this helps. By the way, what part of the Southern Tier are you in? I'm just south of Broome County...

Cheers,
Larry

Other than the shuttle levers coming loose at the mount screws and causing an intermittent short, I have had few lever (switch) failures. I recall swapping out maybe two shuttle controls and probably a couple dozen pressure switches counting their use in the MFD and regulated circuits in both TN and TL series tractors. The latest level pressure switch is a great improvement. If you see any traces of oil around the terminals of the original pressure switch, it is junk for sure.

 

[SBParks]

Larry,

I am located close to Binghamton, New York. Out in the country, of course (why else would I have need for a cool tractor!).

Rick,

After posting the question, I did take a look and identified the symbol as the brake fluid indicator lamp. I'll take a look to top it off. Likely nothing to do with my transmission issue.

Also, I checked around to try to identify the pressure switch you alerted me to. Left, rear side of the tractor... I din't remove the wheel, but I did my best to look around in there. I wasn't able to identify it. I saw what appeared to be a small (hard) tube coming off the top of the differential. Some wire groups, but nothing I was able to identify as a pressure switch. I couldn't see what you described as an access panel either (I assumed to be a part of the fender. There is room between the bottom of the fender and the top of the fuel tank to reach into that space (if I removed the rear left wheel).

Could I trouble you to provide further detail so that I can, at least lay my eyes on the switch?

Thanks!

 

[RickB]

Larry,

I am located close to Binghamton, New York. Out in the country, of course (why else would I have need for a cool tractor!).

Rick,

After posting the question, I did take a look and identified the symbol as the brake fluid indicator lamp. I'll take a look to top it off. Likely nothing to do with my transmission issue.

Also, I checked around to try to identify the pressure switch you alerted me to. Left, rear side of the tractor... I din't remove the wheel, but I did my best to look around in there. I wasn't able to identify it. I saw what appeared to be a small (hard) tube coming off the top of the differential. Some wire groups, but nothing I was able to identify as a pressure switch. I couldn't see what you described as an access panel either (I assumed to be a part of the fender. There is room between the bottom of the fender and the top of the fuel tank to reach into that space (if I removed the rear left wheel).

Could I trouble you to provide further detail so that I can, at least lay my eyes on the switch?

Thanks!

You likely won't find it without removing the LR wheel. The transmission control valve is ahead of the LH axle housing. I can change the switch lying below the tractor, but only because I know what to feel for, and what size tools to use. I can get a hand up between the tank and housing to unplug the wires, then inside the wheel and above the tank with a socket and extensions to swap the switch. Doing it without a prior visual observation of the components would be impressive, indeed.