6340E not engaging 4 wheel drive

[jock_rosie]

Hi I have a M reg 6340E that won't engage 4 wheel drive. It struggled to connect for the past year but now it won't connect at all. A friend thinks it best to replace the whole front axel but I wanted to get some advice here before venturing done an expensive unnecessary route. Could it be something other than the front axel or how could I test it to prove the fault is in that area. Any help or advice would be great

 

[Renze]

Front axle replacement is nuts. But you might want to check the dog clutch under the gearbox for wear and tear. The lever could also be bent due to a stick or rock poking up from the ground.

 

[ixer0]

Which axle do you have? Zetor or Carraro?

Mike

 

[jock_rosie]

Renze - Yes I was thinking its a bit extreme, I'll try what you've said and get back to you.

Ixer0 - I don't know what type of axle it is, the aluminum serial number plate has corroded so badly with silage effluent. Its a heavy cast axle with a hard stamp "6045 3126 B" on the near side rear facing. Does that mean anything ?

Away to lamb some more ewes......yawn

 

[Renze]

Thats the Zetor axle then. With a heavy frontloader and selflocking difflock, occasionally a hub input driveshaft snaps. Will the tractor move forward when you stick a rod in the U joint and turn the shaft like that ? If so, its simply the dog clutch itself, or the operating mechanism.

 

[jock_rosie]

Thanks Renze I had a suppler ask what type of axle it was and couldn't comment, I know for again.
I lifted the front wheels off the ground with the loader yesterday, when I turn either wheel it is still turning the shaft back at the output from the dog clutch so I'm thinking its the like you said - either the dog clutch itself or the operating mechanism. When I went under the tractor and pulled down on the engage mechanism it seemed too free, as if it wasn't doing/attached to anything.
I've asked my friend to come back to see me and look at my findings.

 

[Renze]

You must really try to move the tractor by turning the propshaft, not the other way around. The propshaft has no friction so it will allways turn with the wheels,even when a wheel shaft is broken

 

[jock_rosie]

I managed to get it to engage today whilst pushing up a manure heap, worked no problem and front wheels were spinning. Does this make it point even more towards the dog clutch area ?

 

[Renze]

Yes, definately. If you busted the teeth of the crown gear, you wouldnt be able to spin tires with a frontloader.

When looking at the lever, underneath, do you have visible confirmation that the lever is in the lowest slot ?

I get a feeling the lever is out of the slot and youre just fishing around with it, and its not locked in position so the slightest force on the dog clutch makes it kick itself out of gear.

I welded a piece of M8 bolt on the lip of the lever, so my brother and father could no longer twist the lever the wrong way, breaking the spring and pulling it out of the guidance slot.

 

[jock_rosie]

Underneath is very corroded as well, I can see the remains of an old guidance spring and also the top (2wd) and bottom (4wd) locators. It is making it to the lowest point and there seems to be nothing externally that is restricting the lever or handle. Most of the time it doesn't seem to be doing anything which makes me think there is play/wear in the clutch assy ?

 

[Renze]

Without that spring it will jerk out of gear at the slightest bump. I used a generic spring and mounted it with metal wire at the tension that felt about right.