TC40 4 wheel drive quit working

[4tillingdirt]

My brother as a 2003 TC40 and he noticed that 4 wheel drive will no longer work. He didn't hear any popping or other strange noises, but just noticed that the tractor wanted to spin the rear tires on a section of yard that normally it would not. The lever for 4 wheel drive operates smoothly and isn't bent. Any ideas? I pulled a diagram off new holland's site showing the breakdown of front axle and there is a pin in a coupler that ties two shafts together but my guess is that is not a shear pin.

Thanks

Eric

 

[Spicer]

All of front drive-line components are on splines. The pins are for retaining components on these splines.
1. Check if the 4wd lever is actually actuating the linkage.
2. Supersteer models have an additional 4wd lock pull handle located on the left side of the base of the seat. This lever locks a one way clutch in the drive-line.

Mike

 

[RDrancher]

Shear pin or not, the front pin sheared on my TC and allowed the coupling to spin on the splines. The splines on the pinion are a lot tougher than the ones in the coupling. A new coupling and pin fixed it.

 

[Spicer]

Did it make any noise while the coupling was grinding away on your spline?

Mike

 

[RDrancher]

Just a light clunking sound at first, which I couldn't detect from the seat. My wife actually noticed it while I was grading our driveway.

Here's a link to my thread on it.

http://www.tractorbynet.com/forums/new-holland-owning-operating/259888-tc35d-4wd-noise.html

After I lost 4wd completely there was no abnormal sound, just no 4wd.

Edited to add: It's not in my linked thread, but the splines in the coupling were almost completely gone. I would think that they are pretty soft compared to the splines on the pinion.

 

[jinman]

I'd say with this type of problem, dropping the driveline is the first and easiest thing to get started troubleshooting. You might get lucky and find a simple and easy solution. Having a roll-pin punch set handy is my recommendation.