M7030 Front Wheel Fluid Leak

[bsekf]

I found the axel was low on oil and added 75-90 gear oil. I am not using the tractor much so will see how much oil it is leaking. Do I dare use corn head grease in that front axle in an attempt to stop the oozing? I have attached a picture, it shows the drain plug and the fill/level plug. What is the plug inside the nut in the middle of the picture? You can also see the seal that is oozing. The second picture shows the axle fill/level plug, that's where I would put the corn head grease.

 

[Harry in Ky]

The center housing is separate from the final drives. I wouldn't suggest putting grease (cornhead or otherwise) in any of them. Just my opinion.

The cap on top with the grease fitting. It has four bolts holding it in place. Are those bolts in a square pattern or are they in curved row? There's apparently a difference between an "old type" and "new type". Old type has the rectangular bolt pattern. The book shows something like what's in your first photo. They call it an adjusting bolt. It has shims under it. I have no idea what it would adjust. It might be explained better in the WSM.

 

[Smokeydog]

I think that axle has three compartments. Axle and each hub. Adding corn head grease to the axle would not effect a leak on the hub.

Monitor. Few ounces per year wouldn’t mind too much.

 

[bsekf]

I have some 75-140 gear oil rather than corn head grease. I am going to pull the grease fitting and see if that is low too. Not sure where you check the level. I was surprised when I took the fill/check plug out of the axel, there was a vacuum in the axel. I have added about 1 1/2 quarts gear oil. Got to build a tool to inject the gear oil. I can't figure out where the axel is leaking. The only oozing was at the seal in the bottom of first picture, opposite the bolt to adjust shims.

 

[Smokeydog]

Your axle looks very similar to the M5030DT.
Axle, the large plug is for fill, small plug to the right and slightly lower is the fill level. Going by memory of WSM. Do what your manual says.



My tractors stay in 4wheel drive. Hillside farm. I couldn’t see how the front axle vented so a used the fill plug with fittings, SS tubing, Tygon tubing, sintered filter to raise and vent the up along the radiator. How the hubs vented was always a mystery. After a long day of bushhogging in summer axle and hubs slightly warm.

Miss the auto locking front axle on the M5030. Do like the one compartment with dipstick on the M59 front axle. Greater FEL lift capacity.

 

[5030]

The grease is just for the top cap. It's not connected to the lubricated parts inside.

Very good. The grease fitting it to lubricate the radial contact area between the upper knuckle and the center section.

Repairing the 'oozing' all depends on where it's oozing at. If the oozing is collecting on the wheel rim inside, it the outer planetary seals. If the oozing is between the upper and center section or between the center and lower section, it's the radial seals that you can see (black rings). The reason why they start oozing is the insert bearings that carry the through pin have become sloppy and are allowing too much slop to exist and the the radial seals can no longer seal the lower and upper sections to the center section and must be replaced as well as the seals and it will only get worse as the insert bearings wear more.

You can do it yourself but be apprised the outer planetary assembly is heavy and is located using locating dowels in the inner gearcase and it must come off straight and go back on straight and there is a large 'O' ring that seats in a milled groove in the outer planetary assembly that has to be in that groove 100% to seal plus you need to coat all the mating surfaces with 3 Bond, not dime store RTV either. The upper and lower insert bearings must be press fitted into the upper and lower sections, as well and installed straight and true or they will fail.

My suggestion is, it you don't have the equipment to lift and align the outer planetary assembly to remove it and reinstall it (I use a cherry picker myself( or don't own a precision seal / bearing driver, take it to a Kubota dealer and not some shadetree wrench either. The tools requires to effectuate the repair are specialized and the assemblies are heavy. I've dome my own in the past on both my M9000's, which are getting pretty old 2000 and 2002 and get worked hard. If you do it, pay close attention to the fastener torques listed in the shop manual as well. Correct torque on the radial seal between the inner housing and the outer planetary assembly is critical as well as the fixing nut that preloads the lower and upper sections to the center section and effective sealing of the radial seals is dependent on correct torque.

Again, the zerk fitting only provides lubrication to the radial sliding surfaces on the upper and middle section and there are a set of level and fill plugs, 2 on each outboard, and one drain plug on the very bottom as well as a level and fill plug on the center section near the axle pivot and the axle pivot needs to be greased regularly and the pre load checked regularly as well or the center section will start 'oozing' as well when the slop gets too much.

When replacing the fluid, don't use UDT or SUDT, use 80-90 0r 85-140 GL4-5 hypoid oil. It provides much better shock load and the higher viscosity don't ooze as much.

 

[5030]

Your axle looks very similar to the M5030DT.
Axle, the large plug is for fill, small plug to the right and slightly lower is the fill level. Going by memory of WSM. Do what your manual says.



My tractors stay in 4wheel drive. Hillside farm. I couldn’t see how the front axle vented so a used the fill plug with fittings, SS tubing, Tygon tubing, sintered filter to raise and vent the up along the radiator. How the hubs vented was always a mystery. After a long day of bushhogging in summer axle and hubs slightly warm.

Miss the auto locking front axle on the M5030. Do like the one compartment with dipstick on the M59 front axle. Greater FEL lift capacity.

Never, never leave the front axle in the locked position all the time, it's not designed to be used like that. It's 'Front wheel assist' and why it can be engaged and disengaged and should only be engaged when needed. Keeping it engaged all the time puts great strain on the internal gearing especially when turning hard plus it wears the front tires excessively.

The front axle is vented with a vent and short hose on top of the center section directly above the center pivot of the center axle casting. Hard to see, but it's there, tucked up above the center section. I have more than a bit of experience with the front axle assemblies as I usually get to tear them apart and reassemble them at my Kubota dealer where I work part time. It's a messy job that always seems to get relegated to me.

If you attempt to take on apart and repair it. I suggest getting a copy of the pertinent section of the shop manual. There are a couple outlets where you can obtain a PDF copy online. Like I said previously, torque specs are critical as well as using the correct sealants, in this case, 3 3 bond and not regular RTV as well as a special bushing driver and the insertion of the bushings as to how far they need to be inserted is critical as well.

Been there and did it more than once, not only on my personal units, but customer units as well.

They all wear out eventually and when they do, they 'ooze' lubricant as the seals can no longer contain it.

Kubota isn't unique to that. All the FWA tractors will leak as they wear.

 

[bsekf]

Got everything full and ran the tractor for 3 hours, both 4wd and 2wd, no oozing yet. I believe I'll use the 00 oil/grease to fill everything, it pours.

 

[5030]

I'd be very careful doing that as the gearing requires liquid splash lubrication and cornhead grease won't provide that nor will it adequately lubricate the roller and ball bearings. That is especially true in colder weather. It may work but then it may not and failure of the front axle will be a very expensive fix.

Your tractor, your dime. Me, I'd fix it right and hot use some half baked idea.