Diagnosing 4WD problems YM240D

[woolyAcres]

With the front end up in the air and 4WD NOT engaged, should both wheels turn freely? What about independently?

My driver's-side front wheel is making a clicking sound and won't turn in a full circle (by hand) when the front wheel are raised off the ground. I could probably drag it in a circle if I were to lower it to the ground and drive (forward or reverse) but I'm concerned that something is out-of-whack that I can easily repair and don't want to force it for fear of really breaking it.


Here's what happened. I've been using the FEL to move some dirt/stones. After moving several loads with no problem, I backed up to get another load, while pushing into the pile i noticed my wheels turning very sharply. I took it out of 4WD and tried to back up. Same 'clicking' of the front wheel. I used the FEL to raise it off the ground and in 2WD the driver's-side won't turn in a full circle. The passenger's-side turns freely.

Any guesses as to what's going on? Any suggestions on where to begin fixing it?

Thanks in advance.

 

[PILOON]

Normal operation with wheels raised is turn one wheel clockwise and the other will turn counter clockwise.
That confirms proper differential operation.
Your description makes me think an idler gear in the differential is damaged, or perhaps the left shaft is stripped with a piece jamming the right side linkage.

Sorry to offer bad news but think you have spit open the frt differential to get an accurate diagnosis.
Splitting is not all that complicated, just be careful and use solid stands to support the raised front end while working under there.

Fortunately there are a few good Yanmar parts suppliers here on TBN so you should be able to source parts fairly easily.

Good luck and keep us posted.

 

[winston1]

With the 4 wheel drive not engaged your symptoms would lead me toward gears in the drivers side spindle or stub axle gears or bearings. The right wheel could be turning freely back through the differenctial and the disengaged drop box. Much more trouble the the wheel ends than differentials. Also the clicking you are hearing in that wheel indicates that. I would drop the lower knuckle and have a look. This might help you. Yanmar KNuckle Seal Replacement Instructions.

 

[woolyAcres]

@Piloon, @WinstonThanks for the comments. It's not the news I was hoping for but it's pretty close to what I feared. It sounds like Winston's suggestion is a bit easier to get to so I'll probably start there. Hopefully I can look at it tomorrow. If not it could be a couple weeks. My guess is it's best to leave it where it is though moving it to someplace flatter and with some shelter sure would be nice. I'll keep you guys posted but I'm headed out of town for a couple week starting Tuesday so don't hold your breath. At least I don't have an immediate need for this tractor....Thanks.p

 

[California]

moving it to someplace flatter and with some shelter sure would be nice.

I agree moving it with damaged gears could make it worse. Could you chain the loader bucket down to a sheet of plywood, get the front tires off the ground, and toboggan that backwards back to the barn or at least to a better repair location? Steer with the brakes.

 

[woolyAcres]

I was able to get the tractor backed up onto a more level spot. Not ideal, but using the FEL I was able to raise both front tires off the ground, put it in 2WD and reverse slowly. I only had to move it about 25' in this manner.

I got the front, driver's-side wheel removed and dropped the Knuckle following Winston's post. Once the knuckle was 'on the ground' I could look at both the front drive gear and the bottom spindle gear. Both looked good. No chips, no cracks, nothing. I was kinda hoping the bearing in there would be obviously cracked with a ball loose, or jamming things. No such luck. It all looked good. The portion inside the knuckle housing seemed just fine. It spun freely and very smoothly. I don't think there's any damage there.

I jacked up the rear of the tractor and in 2WD the rear spins freely and smoothly. One tire forward, one backward everything in the rear seems fine thankfully. But the problem I was having seems in the front seems to have migrated to the passenger's side. With the driver's-side knuckle on the ground, I was unable to spin the front passenger wheel when in 4WD. I ran out of daylight to check that knuckle, but I'm starting to think Piloon diagnosed it correctly, or at least taking apart the front differential is going to be required to figure out what's going on. Before committing to that job however, I'll pull down the passenger-side knuckle just so I know what's going there and because it's not too hard. Maybe I'll get lucky and find something jammed in there....

More in a couple weeks when I get back from work travel.

Thanks

 

[winston1]

Sounds like you are on top of it. I think you are taking the right course even though you may end up taking the differential apart. You feel pretty confident the drive shaft is ok? Been several cases of the drive balls coming out. With your noise coming from the front doesn't seem likely. just putting things out there to consider.

 

[woolyAcres]

I'm finally able to get back to working on this. If I want to look at the front differential, can I simply split it there (take each half off, but with the half in one piece) or do I have to remove things piecemeal, slowly stripping it away as I get closer to the differential?

 

[winston1]

I'm finally able to get back to working on this. If I want to look at the front differential, can I simply split it there (take each half off, but with the half in one piece) or do I have to remove things piecemeal, slowly stripping it away as I get closer to the differential?

Haven't been there, done that, but, just looking at part drawings would indicate you can do that. However, that axle and knuckle is going to be heavy so be sure and support it well. Looks like the splined axle shaft should slide right out of the differential. Don't go to the bank on my advice, basing this solely on what the drawings indicate.

Evidently you are confident your problem is not in the drive shaft area?

 

[woolyAcres]

@winston1- I missed the notification about your post but I can say after 'being there, doing that' that you are correct.

I've pulled everything to the driver's side of the front differential off (in pieces). I think I know that the problem is but still don't have a solution for it. Here are some photos of the progress. Referring to Hoye's parts page..
I managed to get to get the 4WD spindle (#44) but I cannot get the bottom spindle gear (#53), the Bearing (#58) or the top spindle gear (52) to come down out of there.

Now that the spindle is out of there, I can reach in from 'above' and tap it downward, which is what I started doing but it really seems stiff and I'm afraid of what I might damage trying to drive that spindle-bearing-spindle assembly downward. The snap ring (#28) is out, as are parts 47, 48, 49, 50, 51. The spindle (44) and associated parts came out the top.

At this point I know I need to replace the top seal and bearing (59 and 28). They got damaged on removal. I'm hoping the bottom and top spindle gears are okay, but they are absolutely frozen. I can not rotate the bottom spindle. No way, no how. Which is why I'm trying to get those out.

Any ideas on getting those down out of the housing?

Thanks

The first photo (the one of the spindle bearing and greasy fingers) was taken before I got the spindle etc removed.