L4701 HST 4WD not working (2015 Model)

[koriley]

I have a 2015 Kubota L4701 HST with 275 hours on it. I used it last summer/fall and the 4WD worked. However, when I went out and started it yesterday, the 4WD did not. I know on the HST's you pull-up to engage the 4WD. Hoping there is a fuse/solenoid, etc., that might be causing the problem. Mechanically, it feels no different than before (i.e. that it is going into 4WD). Any help you can give is appreciated. Thank you.

 

[chim]

Try pushing it down.

 

[koriley]

I have, thank you. Mechanically, it feels no different than it ever has moving up or down. Much appreciated.

 

[Yooper]

Try raising the front end with your loader and then try engaging it. This works well for disengaging the 4wd so maybe it will work for engaging. I don’t think there is anything electrical involved

 

[NCL4701]

Unfortunately I don’t have an answer but I do know:

1) Up is 4wd on the HST. (Pretty sure it’s opposite on DT but that’s irrelevant.)
2) If it won’t go into or out of 4wd because it’s bound up, the shifter will NOT move. It feels very mechanical when shifting. Not like pushing a button to activate a relay.
3) If the shifter can be moved up without actually engaging 4WD as described by the OP, something be busted.

Based on not much other than when acting right it acts very much like a mechanical shift controlled directly by the shifter, I would definitely start by locating and inspecting the linkages attached to the shifter.

I’m aware that probably wasn’t helpful. Main point of posting anything was to agree the behavior you describe indicates something broke somewhere.

 

[koriley]

Unfortunately I don’t have an answer but I do know:

1) Up is 4wd on the HST. (Pretty sure it’s opposite on DT but that’s irrelevant.)
2) If it won’t go into or out of 4wd because it’s bound up, the shifter will NOT move. It feels very mechanical when shifting. Not like pushing a button to activate a relay.
3) If the shifter can be moved up without actually engaging 4WD as described by the OP, something be busted.

Based on not much other than when acting right it acts very much like a mechanical shift controlled directly by the shifter, I would definitely start by locating and inspecting the linkages attached to the shifter.

I’m aware that probably wasn’t helpful. Main point of posting anything was to agree the behavior you describe indicates something broke somewhere.

Thank you very much. I greatly appreciate the information.

 

[North Idaho Wolfman]

Can I ask how you know it's not working?

 

[chim]

On my L4240 HSTC 4WD is down.

 

[Trapper Bob]

On my 2018 L4701, pull the lever up to engage 4WD. Sometimes I have to lightly tap the HST treadle forward or reverse to get it to engage (there is a slight click you can feel & hear). If it does not want to engage, I check the position of the front wheels. It engages best with the front wheels straight.

 

[Firefight100]

probably the coupler on the front driveshaft has slipped out of position.

 

[koriley]

probably the coupler on the front driveshaft has slipped out of position.

It looks like the splines wearing out (or wearing off) inside the front driveshaft coupler is a pretty common issue, and that the couplers run about $25 each. Is this what you are referring too? Thanks much.

 

[Firefight100]

there is a pin to keep the coupler centered. They are prone to falling out an the coupler sliding off one of the drive shafts

 

[koriley]

I picked up two couplers and two pins yesterday. They were pretty easy to install, getting the cover back on was a little more tricky at the end (rusted). The existing couplers did appear to be in pretty good shape, but I replaced them anyway. However, The pin on the front was broken and the coupler had slid back on the axle.

After replacing both couplers and both pins, the 4WD appears to still not be working. While I had the axle off I did engage/disengage the 4WD and the spindle coming out of the back of the tractor would lock when engaged, and move freely when taken out of 4WD.

I'll try a few of the other suggestions provided earlier.....hoping something will work. Any suggestions are appreciated. Thanks.

 

[old and tired]

Are you sure the rims are not spinning around the tire? It's been recorded several times before...

So how do you know 4x4 is not working, for sure?

If you don't have someone to watch the front rims, set up a video camera...