Problem with 4 wheel drive Kubota L4200

[Dwilson540]

I have a Kubota L4200 that I've owned for almost 25 years. Great Tractor and I'd buy it again. But just recently it seems the 4 wheel drive isn't working in that the front wheels don't provide any power. Someplace I read that this can be caused by the failure of a ring or something like that where the linkage from the rear wheels hooks up with the linkage from the front wheels. The way I remember reading it, there's a gray box underneath the engine where the linkage hooks up. I'd like to know more before attempting this. Anyone out there with experience with this problem?

 

[5030]

Most likely it's the coupler that fits between the front propeller shaft and the pinion shaft on the front axle. Kubota uses a soft metal splined coupler that is designed to wear out and it's soft so the splines on the output shaft and the pinion shaft don't get worn.

Your dealer will have one. Easy to replace too. Remove the screws that retain the driveshaft cover, slide the cover back exposing the coupler. Drive out the one or 2 roll pins that retain it and slide it back on the rear input shaft, lower the shaft enough to remove it and replace with a new one. About a 30 minute job and the coupler retails for around 45 bucks. Coat the splines on both shafts with grease before installing and don't forget to replace the roll pin(s).

I've done that numerous times on my M's.

 

[Dwilson540]

Thanks, that’s what I thought as well. Watched a YouTube video and removed it for inspection. Everything looks good. Even had someone at the dealer look at it to confirm I wasn’t missing anything. The linkage below the shift lever seems to move ok. I’m not hearing any strange noises. We’re soon going to get above my pay grade, but I would like to have an idea of what it is before I turn a real mechanic loose on it.

 

[rbargeron]

How many hours on this L4200? With 4wd lever engaged, and one front wheel jacked up, can you turn the jacked up tire by hand? If its free to turn, something inside the front axle or transmission is broken or disconnected.

My first 4wd machine (a jeep) had been left in 4wd all its life. Due to the built-in ratio mismatch the gears were in hard mesh all the time. The front pinion and ring gear teeth had completely worn away and were no longer making contact.

 

[Dwilson540]

I’m not sure of the hours. The hour meter stopped around 1,900. I’ve owned it for about 23 years and I doubt that I put 50 hours a year on it on average. But I will check your suggestion in a few minutes. Snow is melting and supposed to get above 60* today! It has spent most of its time in 4 wheel drive.

 

[Dwilson540]

So this is a problem?

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this is a link to a 15 second video of the wheel freely turning. Now I’m going to YouTube to see if anyone has posted a video of front axle repair. My guess is that it is front axle because of the lack of resistance. Would that be a safe assume?

 

[5030]

If you ever bothered to read your owners manual, you'd see that Kubota only recommends using FWA (or 4 wheel drive as you call t) only when necessary.

 

[5030]

If it's front axle, have fun. If it was me, I'd have it fixed at a Kubota dealer. Takes quite a few specialized tools to take it apart and put it back together and there are a lot of critical clearances involved too. You ever set drive pinion lash and used paint marker to determine tooth contact and set the pre load on a vehicle. If not, you'd be better taking it so a dealer where the mechanics have done it before.

It's just like the differential in a car plus the outboards and they have to be set as well.

 

[rbargeron]

So this is a problem?

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this is a link to a 15 second video of the wheel freely turning. Now I’m going to YouTube to see if anyone has posted a video of front axle repair. My guess is that it is front axle because of the lack of resistance. Would that be a safe assume?

Nice video! The tractor does look experienced, like it has seen a lot of pavement.

Assuming the 4wd lever was engaged during the test, if the shifter inside the trans has jumped out of its groove the turning resistance using a foot on the tire would not be very much - problem could still be be back there. Another possibility is the outside 4wd shifter lever is bent or its roll pin is sheared off.

Before splitting the tractor, I'd unbolt the housing under the seat and have a look down inside. Not unheard of for a shifter to need to be pried back into its groove. (I always hope for the easiest fix )

 

[Dwilson540]

If you ever bothered to read your owners manual, you'd see that Kubota only recommends using FWA (or 4 wheel drive as you call t) only when necessary.

Thanks