Non functioning MFWD (manual front wheel drive)

[yanmars]

I have a 45 HP Mahindra 4510. The MWFD just quick working. The 4wd lever will go forward and backward (on and off) and the lever moves but the MFWD is not functioning. The only thing I did differently was tighten up the jam/lock nuts on the clutch and brake rods. Both had the correct amount of freeplay but the jam nuts were not tight at all.
I could live with this except I have hilly, wet ground. Pulling logs up the hill is OK due to the weight on the rear. Going downhill I have to be careful as it wants to gain speed or free wheel and have to use the front end loader to keep speeds from getting to great. Also any backing up on a slight incline or in too wet an area and I am nearly stuck without the front wheel assist.
The unit seems to be mechanical, levers and rods to function, no fuse or electronics involved that I can tell as compared to the PTO.
I am getting by but am careful and would have a lot more success in pulling and general use if the MFWD functioned. Any thoughts/cures? I will use a flashlight tomorrow to make sure nothing is impeding the rods/levers of the unit. Thanks

 

[LouNY]

You will need to get under and check out all your linkages for shifting into 2wd/4wd.
If they are good how shielded is your front driveshaft.
You will need to check the couplings on both ends of the driveshaft.
One way will be to move any coupling guards so the couplings can be seen,
then lift the front axle of the tractor in the air and turn the front tire,
you may need to block one so it doesn't turn and just turn one while watching the drive shaft,
either drive coupling could be broke either the axle end or the transmission end,
if the shaft is turning and you can see the output shaft from the transmission turn from the
driveshaft turning it is internal.
Possibly a shift collar potentially much more.

 

[yanmars]

I have a better idea of what happened. The linkages are all good. In getting under the tractor there is a splined shaft that runs from the front axle to the transmission. The shaft is protected a bit by a hollow tube. The tube has pulled away about 3/4 inch at the transmission. I can see the splined shaft there. Unsure internally what is broken/damaged on the shaft.
I am sure it must have occurred when I was using the FEL pallet forks and lifting and moving fairly large logs. In getting to them I probably ran over some larger limbs or logs and made contact with the shaft. I guess I will bring it into the dealer for repair in the next month. Hopefully it can be back before Spring.