4 wheel drive

[tsoasb]

I have a New Holland TD 50/50 2008 model. The 4 wheel drive engagement lever moves easily just as it always has, but the machine will not go into 4 wheel drive. I have crawled under the tractor and the lever moves just as easy from down under, but still no 4 wheel drive. Any suggestions???

Thanks, Scott

 

[k0ua]

I have a New Holland TD 50/50 2008 model. The 4 wheel drive engagement lever moves easily just as it always has, but the machine will not go into 4 wheel drive. I have crawled under the tractor and the lever moves just as easy from down under, but still no 4 wheel drive. Any suggestions???

Thanks, Scott

Well I cannot be a whole lot of help, but I would try to learn where it is broken. I would start by getting the front tires off the ground. make sure the lever is in 2WD. Get a couple of jackstands and get the front tires off of the ground, and then, (and you may need a helper) turn the front wheels by hand and see if the driveshaft turns when the wheels turn. If the drivshaft rotates as you turn a wheel, then the front differential and axles (take turns and turn both wheels) are likely intact. If one axle is broken or the gears associated with that front axle shaft, then it would appear you would have no front wheel assist because the broken stub of the axle shaft would always turn easily and never allow the good axle to provide any pulling power as there would never be anything for it to push against and the diffferential action would cause the spider gears to rotate around their shafts. Also note if you turn one wheel forward if all is well the other should rotate backward.. And again the drive shaft should rotate. If all is well in the front axle and differential and drive shaft. then shift to 4WD and you should bind up and not be able to turn the wheels much and the drive shaft should not rotate as the rear wheels are still on the ground. If the shaft continues to rotate, then the problem is in the rear, with the engagement mechanism or the shaft splines are wallowed out, or technically it is broken. At least you will know which end of the tractor to start taking apart.

 

[ovrszd]

I'm with James.

Only caveat is that when you rotate one front wheel forward the other should rotate backward, and the driveshaft will not rotate, because all the movement is transmitted by making the opposite wheel rotate the opposite direction.

To get the front driveshaft to rotate you have to rotate both front wheels the same direction.

Most CUTs have an enclosed driveshaft to the front, so it's gonna be hard to detect rotation anyway.

You never expressed any extreme failure, breakage sounds, abusive use,,, so I'm gonna say it's a simple problem, not necessarily easy to fix. The shifting fork that engages the 4wd may have sheared the roll pin that connects it to the shaft, so engagement of the lever, which rotates the shaft, is not moving the shifting fork. That would mean breaking the tractor open. Not good.

Start with the simplest and easiest thing to fix and work your way up. Good luck and post the results. We are all curious.

 

[tsoasb]

Thanks guys .....I am an old man and seldom put things in a bind. I do not remember any breaking noise or obvious failure, but a brother in law did use it for some heavy duty brush busting with no reported problems. As soon as it warms up I will attempt to diagnose further.

 

[k0ua]

I'm with James.

Only caveat is that when you rotate one front wheel forward the other should rotate backward, and the driveshaft will not rotate, because all the movement is transmitted by making the opposite wheel rotate the opposite direction.

To get the front driveshaft to rotate you have to rotate both front wheels the same direction.

I kinda forgot that point didn't I..I think you can see Most of the shaft, as they pass thru the Oil pan channel. Of course I don't know what his NH looks like.

Most CUTs have an enclosed driveshaft to the front, so it's gonna be hard to detect rotation anyway.

You never expressed any extreme failure, breakage sounds, abusive use,,, so I'm gonna say it's a simple problem, not necessarily easy to fix. The shifting fork that engages the 4wd may have sheared the roll pin that connects it to the shaft, so engagement of the lever, which rotates the shaft, is not moving the shifting fork. That would mean breaking the tractor open. Not good.

Start with the simplest and easiest thing to fix and work your way up. Good luck and post the results. We are all curious.

James

 

[tsoasb]

OK ......with the tractor running and in neutral, I can pick up the front end with the loader. Both front wheels will freely turn. When you turn one the other stays still.........does not matter if it is 2 or 4 wheel drive.

Scott

 

[k0ua]

OK ......with the tractor running and in neutral, I can pick up the front end with the loader. Both front wheels will freely turn. When you turn one the other stays still.........does not matter if it is 2 or 4 wheel drive.

Scott

Uh, Oh.. not good.. broken parts in the front differential or axle. Did turning either wheel make the drive shaft move?

 

[jimmysisson]

If you turn one wheel and the other don't turn, the driveshaft still can turn in a correct setup. Best check that. Just wantin it to be cheap for you.
Jim

 

[tsoasb]

Got it figured out yesterday. Took the front drive shaft cover off and the slip spline connection to the front differential had come off. There was a small ring that holds it on that some brush must have pushed off. anyway, slip it back together and put ring back in place and GOOD TO GO. By the way, with front diff disengaged either front wheel will spin without the other wheel turning. With the 4 WD engaged, then turn one wheel and the other turns the opposite way. Drive shaft looked like about 1 1/4" cold roll, which looks small to me to be driving what it is driving.........just my opinion.

Scott

 

[k0ua]

Got it figured out yesterday. Took the front drive shaft cover off and the slip spline connection to the front differential had come off. There was a small ring that holds it on that some brush must have pushed off. anyway, slip it back together and put ring back in place and GOOD TO GO. By the way, with front diff disengaged either front wheel will spin without the other wheel turning. With the 4 WD engaged, then turn one wheel and the other turns the opposite way. Drive shaft looked like about 1 1/4" cold roll, which looks small to me to be driving what it is driving.........just my opinion.

Scott

Glad is was the easy cheap kind of "broken" to fix. Glad you got it going.