FWD disengage issue

[afoster]

I have a CT335 with HST drive and have noticed a few times when I disengage the the front wheel drive that it doesn't always fully disengage until I move forward a distance. Then it in disengages with a noticeable clunk. Has anyone else experienced this issue and if so what was involved in fixing it.

 

[joshuabardwell]

I have something similar: if I try to take it out of 4wd, sometimes there is resistance until I let the tractor roll forward slightly to release tension in the drivetrain. I wonder if you may be forcing the lever down and then even though the lever is down, the 4wd is not disengaged, and then once the tension in the drivetrain releases due to the tractor rolling, it disengages?

 

[afoster]

There is no lever in the HST drives. It is a toggle switch that I assume turns the power on/off to a solenoid that engages/disengages the FWD. Though I've had no luck actually locating this solenoid if that is what is used to disengage the FWD.

 

[Patches]

If your tractor is equipped with a loader, use it to releave the pressure of the front tires on the ground, and then operate the 4wd switch; should come out of front drive easily

 

[joshuabardwell]

There is no lever in the HST drives. It is a toggle switch that I assume turns the power on/off to a solenoid that engages/disengages the FWD.

I beg to differ. It certainly feels to me like a mechanical linkage.

 

[SSdoxie]

I beg to differ.

The OP has 335 and like the 4xx models & DK Kioti 4wd uses electric solenoid to engage/disengage. The 2xx models have manual lever.

 

[joshuabardwell]

The OP has 335 and like the 4xx models & DK Kioti 4wd uses electric solenoid to engage/disengage. The 2xx models have manual lever.

Ahhhh. Well, that makes sense then.

How do the 3XX and 4XX handle the "tension in the drivetrain prevents 4wd disengage" situation then? Does it just wait and then disengage whenever the tension is relieved?

 

[afoster]

I've got a couple hundred hours on this tractor and I never noticed this happening till just recently. I'm hoping its just an adjustment to the solenoid or maybe a poor wiring connection, but as I mentioned earlier I've had no luck actually finding the solenoid and I'm starting to wonder if its housed inside the transmission housing. Anyone with experience on the Ct335 with this issue.

 

[SSdoxie]

It uses hydraulic pressure from the charge pump circuit to shift into 4wd and return spring to disengage when pressure is released by turning switch off. I haven't been inside one of these but believe it is a small cylinder that takes place of the manual shift fork that pushes and hold the gear into engage front axle drive. What OP is likely experiencing is tension remaining on the gear so spring can't pull it back until he starts to move and pressure on the gears release.

 

[MBTRAC]

Reversing a short distance prior to/or post shifting from FWA can assist with disenagement.

 

[afoster]

Reversing a short distance prior to/or post shifting from FWA can assist with disengagement.

Since I noticed this issue I have been doing what you suggested hoping to prevent any damage. I'm still hoping someone does know exactly how this shifting works and can give me some direction were to look on the unit to see if there might be some adjustment that needs to be made to solve the issue. As I still have a few months left on warranty I could take it to the dealer and have them look at it but for my own piece of mind I would like to have a better understanding of what's involved in this shifting process. There doesn't appear to be anything in the operations manual and even though I do have the parts manual I have not yet been able to pinpoint the mechanism that does the shifting.