TC40D - No FWD

[Chris Taylor]

Ok so I have a TC40D with supersteer.

I engage the full-time FWD level (the one behind and below the seat)
But no power is going to front wheels

Crank to front wheels is turning (when moving) when full time FWD is engaged. Crank is turning right up to the front (past the sensiclutch lever).

The sensiclutch lever (Auto or Lock FWD next to PTO lever) seems to not opertate the sensiclutch.

Any thoughts?
Hammer/WD40?

Chris

 

[Chris Taylor]

should say that the auto/locked fwd lever has always been in auto and never had trouble before.

I feel that the auto part of it is not being auto....

 

[jinman]

Chris, the sensitrack auto FWD function is controlled by cam action. As soon as the front wheels rotate faster than being driven or driveline windup is sensed, the cams align and relieve FWD. When you manually select full-time FWD, the lever pushes a thrust washer forward and forces the engagement of the gear no matter what the cam position. It would seem that the lever is not pushing the thrust washer forward or that the fingers forcing engagement have been damaged. Have you removed the oil drain plug to check if the clutch has fluid?

BTW: The driveline always turns because it is driven by the front wheels. Only during rear wheel drive only and when the tractor stops due to rear tire spin will the driveline not move. Sensitrack just locks the driveline to the transmission so it is driven by the transmission rather than just rolling along being driven by the front wheels.

 

[Chris Taylor]

cheers for your response, I have just checked the clutch oil. It ouzed out before quickly returning the plug (manual suggests this should be up to the level of the plug)

You said it does turn even in two wheel drive. This does not seem to be the case on this tractor?? When the leaver is disengaged there is no turning of the driveline. when you push it down it rotates.

Sounds like some parts need to be checked internally?

Chris

 

[RobertN]

I got my TC40D used. I test drove it and really liked it. It was a consignment sale. The owner of the dealer/repair shop was showing my wife how the 4wd work, but it didn't... It was debugged/repaired before we actually bought it(owner paid for repairs).

turned out, the bolts holding the front axle ring gear to the differential carrier had sheared. They put a new diff in it. Works great.

I really like this auto sense 4wd, but am concerend about the longevity of the clutch mechanism for it.

 

[dynasim]

Chris,

If the drive in front of the sensitrak is turning while the back wheels are spinning, you diagnosis is correct(something inside the differential is broke).

There have been a couple of cases documented on the forum of the ring gear bolts coming loose in these differentials(both the supersteer and non-supersteer versions).

I plan to check mine this winter(as well as the transmission to engine bolts), as the consequences of them coming loose is not good.

Good Luck, and I hope it is loose bolts.

Chris


P.S. You are correct in saying you can disconnect the FWD drive shaft inside the transmission by the hand lever down on the floor. The Non-SS fellas don't have that.

 

[jinman]

Guys, I'm sorry if I've carried this a bit far, but the old instructional multimedia guy is coming out in me and I decided to draw a bunch of illustrations because there are just too many variables for us to discuss without some kind of visual aid. I illustrated only the main drive components.

Slide 1 below:
2WD Normal and 2WD Failed due to the differential failing.

Slide 2:
4WD Full-time and Sensitrack 4WD normal operation

Slide 3:
Sensitrack Failing to engage and Sensitrack engaged, but the differential is failing

I'm sure you can come up with other possibilities like the transmission failing, etc, but that is not the OP's problem and I didn't want to confuse the issue anymore than I already have.

BTW: I love PowerPoint and its drawing tools. For simple diagrams, it is hard to beat and allows you to build nice slides.

EDIT: And the proof you always need an editor is that I made a mistake on the first slide. At the bottom under "2WD Fail" the box with text saying, "Turning: Driven by Front wheels," should have been deleted.

 

[RobertN]

Any thoughts(or diagrams ) about longevity of the Sensitrack and parts availability?

Barring the unforeseen, I plan to keep my TC40D for a long long time. I wonder what availability of parts will be in 15-20 years? It is already an 7-8 year old tractor.

I'm guessing parts wont be available for most of these tractors, like they are for a Ford 8N, Farmall-Cub, Farmall-A. Before I sold my '41 Farmall A a year ago, the governor spring broke. Got a new spring and gasket from the local Case-IH dealer.

 

[jinman]

Any thoughts(or diagrahms ) about longevity of the Sensitrack and parts availability?

Robert, it seems that the front differential is problematic on a significant number of tractors, both SuperSteer and Regular. I've never had a problem nor sensed my front differential was anything but solid, so I'm hoping never to have that problem. I also don't see why Sensitrack should be a problem. I would think you could choose forced 4wd or 2WD even if the sensitrack clutch was failing, but I don't know that for sure. If you are like me, you want something to work as it should and know that parts will be there if you ever need them. I don't blame you for having long-term parts concerns because it doesn't seem to me that SuperSteer has been a high demand option since its introduction. I'd like to know the percentage of tractors sold with SS, but I'd bet NH wouldn't be releasing that number.

 

[TomOdie]

Chris-
I know this is an old thread... but wondering if problem resolved? I Have a TC35D SS with similar No FWD issues. I suspect the link from the lever under/behind seat. I am still hopeful it is not Differentail bolts! It was bought used with "suspicious" acting FWD locked engagement being 'intermittent' now seem INOP.

Thom