L4400 Front axle cases & bevel gear cases

[McChunx]

L4400 Front axle case rebuild

Hello all. Last month, I replaced leaking oil seals on the front axle cases of my 2006 L4400DT 4x4. This past weekend, as I was using the tractor out on my hunting lease, the left front axle case slipped off when I raised the front wheels off the ground with the loader. (I was 1 1/2 miles out in the woods) Without getting into the gory details, I damaged the bevel gear case, oil seal, and possibly a couple bearings walking it backwards out of a trail and backwards up a trailer to get it home.

Upon breaking it all down and cleaning it up, the damages were not as bad as I originally had assumed, although still about $400 in parts according to TractorXchange.com pricing. (Great site) In case you do not know, there are 3 bearings, three c/e rings, and two shims in the front axle case setup along with a couple seals, shaft and gear. Upon ordering the parts, I discovered that there are several different thickness shims available that go in there. The original shim and bottom clip were destroyed (eaten into a thousand pieces by the bevel gear). I have no way of knowing what size it was. How do I determine what thickness to put in there upon reassembly? I've called all the local Kubota dealers and cannot get a straight answer from anyone. Some have suggested to purchase them all and use the one that is right. At $8 bucks each, I rather not do that of course.

I would appreciate input from anyone that has experience with replacing these parts. I am still dumbfounded as to why the clip failed. I assume that either the clip wasn't seated properly or it was somehow fatigued, but if anyone else has any suggestions I'd love to hear them. Thank you all for reading and have a good day!

 

[Billdog350]

Re: L4400 Front axle case rebuild

Seen this happen before. If you don't seat that bottom c clip 100% into its groove, it will snap out and then nothing is holding your front bevel case on. I always used a $100 set of ratcheting C clip plyers from Napa to ensure I didn't damage that C clip and made sure to get it set in the groove. Once you install it, you should be able to push on one of the ears and spin it around in the groove. If its not seated, it won't move, or at least won't move easily. If you over expanded the c-clip, there is a chance you cracked or bent it, causing it to fall out later.

As far as the shims, the shims keep the gears "meshing" right in the middle of the tooth. If the shims are too far off, you will wear on the tip or inside/outside of the gear rather than the middle. You can use "gear marking compound" to determine where your gears are wearing, and then determine if you need any shims. Honestly, the kubotas are usually pretty damn close out of the factory, even if you didn't use any shims, you'd likely be ok for the life of the machine....

https://www.google.com/search?q=marking+differential+gear+wear+pattern&espv=2&tbm=isch&imgil=_yoGkR4zjyJpqM%253A%253BtxK0QnxxxWG7QM%253Bhttp%25253A%25252F%25252Fwww.pirate4x4.com%25252Ftech%25252Fbillavista%25252FPR-ARB%25252Farticles%25252F14b_Gear_Setup%25252F&source=iu&usg=__u8AnuEU26_A_CBXA9unAbk9jb2A%3D&sa=X&ei=UTDiU9naNsXsoATQhYLIBg&ved=0CCcQ9QEwBA&biw=1366&bih=667#facrc=_&imgdii=_&imgrc=_yoGkR4zjyJpqM%253A%3BtxK0QnxxxWG7QM%3Bhttp%253A%252F%252Fwww.pirate4x4.com%252Ftech%252Fbillavista%252FPR-ARB%252Farticles%252F14b_Gear_Setup%252FIMG_3875_small.jpg%3Bhttp%253A%252F%252Fwww.pirate4x4.com%252Ftech%252Fbillavista%252FPR-ARB%252Farticles%252F14b_Gear_Setup%252F%3B400%3B300

 

[McChunx]

Thanks a bunch for the info. I'm gonna triple check that clip this time for sure! (might even order another and change the other side while I'm at it) It was definitely shimmed before, so I know I'm gotta go back with something. They are little cheaper than I thought, so I'm just gonna get them all and use whichever is right.

 

[Billdog350]

McChunx, the big thing to ensure is that you have properly seated your bevel into the axle housing once you swap the seals. Lots of times those new seals are so tight you have a hard time getting that bevel back installed. Also I have personally missed removing the inner metal sleeve on the old seal (that's left on the axle housing) since it blends right in to the housing. When you try to install the new seal, its a complete PITA and will fight you the whole way.

 

[McChunx]

Thanks again for your responses. I'm getting it all put back together and am not able to fit the original shims back into the bevel case. I read somewhere else that this is common, as the cases themselves will be machines fractions of millimeters different. 6 different size shims are offered for this setup; all within .2mm difference.

Does anyone know the recommended "slop" tolerance when inserting these shims? I believe I'll be able to come within .15 mm after inserting a .8 shim.
I know that one of you told me before that I could probably not shim it up at all and i would be fine, but I just wanted to get one last opinion before bolting everything back up.

 

[bjmsam]

Re: L3710 Front axle cases & bevel gear cases

I am losing the same battle. I just replaced the king pin seals on my L3710 and have had no luck getting cir clip 100 into the groove with shim 095 in place. It could be that there is less clearance now with the new seal, but when I hook the shim on the groove to hold it in place while pushing the clip on from the bottom, I am unable to maneuver the shim out of the groove and up out of the way far enough for the clip to fall in. I don't know where to go from here other than leaving the shim out, so suggestions would be most appreciated.

 

[ThisIsNotaStep]

Had same issue, put final drive back on and lowered front end to put weight on it, compressed the pieces into place. Raised and removed and clip went on "easier" .. you'll need another pair of hands to be sure nothing gets damaged.

 

[bjmsam]

Thanks for your helpful reply! Employing a similar approach, I managed to get cir clip 100 into the groove with shim 095 properly situated by 1) using a jack to keep the case firmly seated for maximum clearance, 2) coating the shim with oil so it would adhere to the bearing race well enough to overcome gravity and not slip down into the groove and block the cir clip, 3) using snap ring pliers to get the cir clip close, and 4) using a small drift to tap gently around the cir clip until it clearly snapped into place with the bright wear ring no longer visible. A few firm blows down on the case confirmed that all is secure, and the steering and spinning actions feel smooth and tight. Success!