MX5100--Change of oil in front hubs question

sixdogs · Mar 9, 2015

I changed the oil in my front axle and hubs of my MX5100 and am not sure about how the hubs get filled. I have an L4300, that I thought was the same axle and you just fill the axle and oil flows to the hubs.

The MX5100 has an extra plug in the front hub that looks like a fill or check port but the owner's manual makes no mention of this port and doesn't even show it in the service section. I just presumed you fill the axle and it flows to the hubs like on the L4300. Here are my pics with arrows to the drain hole and the extra hole on my MX5100.

Anyone familiar with this?

AStanton · Mar 9, 2015

I'm guessing that those might act as air vents. You keep them open as you fill the axle. Then, once oil comes out, you close them off. This would be my guess. I'm wondering if you would even need to add more oil once the oil emerges. If you have a dip stick on your axle, check the level once oil comes out of these vents.
I should of mentioned that my BX-25 has a set of vents on the front axle. However they sit on the top. I don't think my B3030 has any. I'll be checking when I do the 300-hour service.

sixdogs · Mar 10, 2015

The oil did not come out of the hole and while the axle is full I don't see anything when I remove the hub plug. Sure could use the help here.

sixdogs · Mar 10, 2015

Found the answer and never good when you answer your own question. I found this info, in a post about motor oil from five years ago. Here's the quote:

"And another random thing, not to hijack but you have the same (MX5100) machine. I changed my front axle fluid the other day. When you get into it you'll find a fill level plug on each hub (same height as the fill level plug on the axle) which is not mentioned in the operators manual (at least the 08 manual). When the axle is drained so are your hubs, and at refill you need to pull those plugs to properly refill the hubs. Solved the mystery of why more udt came out than wanted to go back in."

It's in this thread--post #4
http://www.tractorbynet.com/forums/kubota-owning-operating/177934-mx5100-oil-change-info-please.html

I'm still double checking this but it's a big discovery for MX5100 and similar tractor owners. Don't fill the hub and burn them up? I'll call the dealer tomorrow but this sounds pretty logical.

Patrickdozer · Mar 10, 2015

Not to familiar with Kubota. Is there a plug on the outside of hub as most equipment with hubs or planetaries have this setup. In that case you position wheel so plug is center line, [at halfway point] between top and bottom position. If you don't have plug on outside then it looks like top plug on hub is your full mark. This plug appears in photo to be same height as the one midline on the axle. if there is no dipstick on axle then this would be your full mark. So It would appear that both plugs would be out and fill to bottom of hole.

Don't know if this helps.

Patrickdozer · Mar 10, 2015

Looks like you just found what I was suggesting. I was a little late with reply

sixdogs · Mar 10, 2015

Patrickdozer said:
Looks like you just found what I was suggesting. I was a little late with reply

That's fine. The hub hole does appear to be lower than the axle line but I didn't look all that close. Will check tomorrow.
There is no other hole on Kubotas like this. They all seem to fill like this while my JD5520 does fill in the center outer hub s you described.

sixdogs · Mar 10, 2015

Patrickdozer said:
Looks like you just found what I was suggesting. I was a little late with reply

That's fine. The hub hole does appear to be lower than the axle line but I didn't look all that close. Will check tomorrow.
There is no other hole on Kubotas like this. They all seem to fill like this while my JD5520 does fill in the center outer hub s you described.

Herkypilot · Mar 11, 2015

I looked in the shop manual.
1. Remove fill plug and the left and right drain plugs.
2. After draining, re-install the drain plugs
3. Remove the oil level check plug
4. Fill with new oil up to the check plug
5. Re-install the check plug and fill plug

I've attached your modified picture with labels that show the proper plugs.

Regards,
HP

Herkypilot · Mar 11, 2015

I looked in the shop manual.
400 hour service:

1. Remove fill plug and the left and right drain plugs.
2. After draining, re-install the drain plugs
3. Remove the oil level check plug
4. Fill with new oil up to the check plug
5. Re-install the check plug and fill plug

Capacity: 9.5 U.S. qts
I've attached your modified picture with labels that show the proper plugs.

Regards,
HP

View attachment 416188