TC40D - 4 Wheel Drive not working.

[jinman]

In looking at my Repair and Parts Manuals, I see there is a linkage arm about 6" long right at the input to the case. You can remove the linkage at that point and move the arm up and down to engage the transfer gear. The shaft goes into the case and has a cam on the end that moves the shifter fork back and forth to engage/disengage the sliding gear. The shifter fork actually has an indent in both positions, so working right at the case, you should be able to feel the positive indent in both positions.

On the front of the case there is a drain plug. If you decide to remove the transfer case yourself, you will have to also drain all your hydraulic oil. The last bit of oil can be drained from the transfer case plug. I hope you don't have to do that. Maybe you will be lucky and find a rollpin missing from the shifting linkage or something instead of the transfer gear being bad.

 

[BOOMERANG]

Well, I finally had time to check out this problem a little further. The problem appears to be in the front axle. The drive shaft engages and disengages just fine when 4WD is selected. The front wheels just spin freely and do not spin the drive shaft at all.

Does anyone know if there is a shear pin or something in the front axle that is easy to replace?

 

[jinman]

Did you remove the cover from the front of the driveshaft and check if the splined collar is in the correct place? There is a collar at both the front and rear of the driveshaft that are held in place by a rollpin. Other than that, I don't have any other suggestion. /forums/images/graemlins/frown.gif

 

[Kent]

Happened to me too...turned out to be the nut on the pinion gear inside the front differential. Well-known problem that my dealer fixed for free (and even trailered 50 miles to their shop for free). The nut just comes off, the pinon gear comes off, no 4wd. The fix is "easy" but requires them to crack open the case. There is no damage to any gears...just used lots of threadlock. It is amazing how much difference not having 4wd makes. When it failed I was doing some light raking on some new loam up a slight hill...rear tires just started spinning. Took me a few minutes to figure out why, checking all the linkages, etc.. Called the dealer and they said "oh yeah, that happens to some tractors...factory just didn't do a good job securing the nut...we'll come get it."

 

[BOOMERANG]

Kent, Thanks for the reply. I had the tractor brought to the shop about a week ago. They just now got around to working on it. The service manager called me this morning and painted a picture of doom and gloom. He said he needs to crack the case open and its going to cost me a lot. I hope the problem is just as you stated! I am going to call him back tomorrow armed with this new information and see how they respond. Your post is VERY timely! Thanks!

 

[BOOMERANG]

Just got a call from my dealer. You were right on the money Kent! He said that even though my tractor is out of warranty, they would cover it as a warranty repair since it is a known defect. It appears they forgot to bend the locking tabs down over that pinion bolt. Thanks for the VERY useful info !