MX5100--Change of oil in front hubs question

[sixdogs]

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]

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]

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]

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]

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]

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

 

[sixdogs]

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]

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]

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]

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

 

[sixdogs]

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

Very informative and very helpful. Thank you. Since I went out yesterday and put some gear oil in the top hole that I'm not supposed to use I guess I now have to drain it down some? I wish Kubota would get their manuals straight.

 

[Herkypilot]

Very informative and very helpful. Thank you. Since I went out yesterday and put some gear oil in the top hole that I'm not supposed to use I guess I now have to drain it down some? I wish Kubota would get their manuals straight.

No worries - glad I could help. Lord knows, I've received a a lot of help from other forum members over the years. Back when I bought my tractor, members on this forum posted that Kubota under-serviced the front axle from the factory. As I recall, mine was about a quart low when I checked it.

HP

 

[LD1]

Those mystery plugs do seem to be about the same height as the check plugs.

My guess is you arent seeing anything because gear lube will take quite awhile to flow through the bearings to fill that hub. I would have thought those extra plugs were so you can fill them instead of waiting on gravity to pull thick oil through small places

 

[sixdogs]

No worries - glad I could help. Lord knows, I've received a a lot of help from other forum members over the years. Back when I bought my tractor, members on this forum posted that Kubota under-serviced the front axle from the factory. As I recall, mine was about a quart low when I checked it.

HP

Thank you. I went out today and drained a little oil out of each hub. I'll let it equalize on its own and check after a couple of hours. Sure wish I didn't have to jerk around like this. And yeah, there are some pretty smart and helpful people here.

 

[Patrickdozer]

I thought the same LD1 or at least it was a means to purge air out when filling.

Looks like your headed in the right direction SIXDOGS.

 

[sixdogs]

Those mystery plugs do seem to be about the same height as the check plugs.

My guess is you arent seeing anything because gear lube will take quite awhile to flow through the bearings to fill that hub. I would have thought those extra plugs were so you can fill them instead of waiting on gravity to pull thick oil through small places

Seems it takes more than gravity since I changed the gear oil last fall and it's been sitting still since then.It must take rolling motion to move the oil and fill the hubs. This would partly explain the "Kubota low oil in the new tractor hubs" syndrome that seems to affect new tractor owners. Apparently, You have to use the tractor to get the oil to move around.