greasing TN rear hub

[jimg]

Been reading again...the manual says when greasing the rear hub the tires need to be turned while pumping grease so its distributed uniformly. A couple questions...how uniform is uniform, how important is it that it be uniform, how do you do this? I cant imagine jacking the tractor every few hours for a lube. Short of jacking either the grease just gets pumped at a single position and the turning wheels spreads it around eventually or its a 2 man operation where one pulls ahead slowly while the other pumps grease. Sorry but Ive never done this drill before.

 

[Soundguy]

Maybee this is where a hand grip or electric greas gun comes in handy... along with some help..

Soundguy

 

[jimg]

Guess so...seems odd the maintenance routine needs two people to do properly.

 

[mahlers]

I just give it a few shots of grease every week or so, and from looking at the opposite side, it sure looks like the grease is getting distributed OK. Something tells me that nobody in their right mind is going to try to grease the tractor while it's rolling, and jacking it up to grease the hubs seems excessive.

 

[jimg]

Thanx...thats what I thought. Theres no way Im going to work on a moving tractor and Im certainly not jacking the thing up every lube cycle. Who writes CIH manuals?

 

[Rowski]

I basically do it as mahlers doe it. Just a shot or two.

I've had my nose in the on-line part catalog for TN series (3+ hours) trying to find a switch for my light problem. I'm getting pretty good at finding things .

I noticed that the grease fitting is lubricating an axle support bearing. The is a seal located to the outside of the bearing. I believe they are recommending that procedure so you don't stress out the seal and lube the bearing uniformly. I also looks like if you really pump a lot of grease in you could stress the inner seal sealing tranny fluid and possibly contaminate the hydraulic oil.

 

[Soundguy]

Interesting.. so thay have a bearing with a seal on either side... I was wondering about that.. IE.. If it could have been splash lubed via the axle trumpet.. but that answers the question.

Soundguy

 

[jimg]

Derek
Thanx for the posting. The operators manual doesnt mention any of this so its hard to make an informed change of procedure. I wondered though if adding grease at one point would result in it being spread around once the tractor was moving. The front hub is completely different w/ an oil fill/drain port in it.

Soundguy...on my first read thru the operator manual I was surprised to discover that the rear hub needed grease. I thought its lube would come from thru the axle. I still dont completely understand why it would be designed this way.

 

[Soundguy]

yep.. lots of axle bearings are splash lubed from the diffy sump. There are obvious exceptions.. like outboard planetaries... and the cases where there is a sealed hub.. like yours. I've seen a few antique examples with sealed hubs.. or externally greased ones.. for instance.. my JD-B has grease fittins where the axles eit the trumpets.. etc.. IH cubs have a pto grease zerk for when you use them as stationary power as they aren't getting splash lubed from the trans gears.. etc..

Soundguy

 

[DieselPower]

May seem like a simple solution to a simple problem but you could alway's install hoses from those grease fittings and remotely mount them. Then you could pump in your grease while the tractor is moving.

 

[Soundguy]

Hey i like that one.. reminds me of the auto greasers on our big milling machine.. has greas lines to a couple places and an air powered grease pump setting in a keg on the back of the machine.. maybee something could be made with a lever activated gun band clamped to the axle.. or perhaps an electric gun???

( neat idea! )

soundguy

 

[DieselPower]

That's what gave me the idea, auto lubers. I have installed "remote lube points" on a couple of trucks and ag tractors before. Usually those impossible to get to ones. All you need is some high pressure plastic line and a couple of NPT thread adaptors for the hose.

 

[jimg]

I cant envision how that would work. The fitting spins w/ the hub. Any line would have to go from the wheel to the tractor frame...sorry I just dont have a good imagination.

 

[DieselPower]

Oh, that wouldn't work then. I was thinking the fitting was on the axle end, not the rotating hub. So more or less it's set up like the grease fitting found on the front hubs of riding mowers?

 

[RickB]

Interesting.. so thay have a bearing with a seal on either side... I was wondering about that.. IE.. If it could have been splash lubed via the axle trumpet.. but that answers the question.

Soundguy

There is only one seal, outboard of the outer bearing. Both outer and inner axle bearings are lubed by the transmission/hydraulic fluid. My understanding is the grease fills a void between the axle shaft flange and the axle seal, effectively protecting the seal with a layer of grease around the outer radial face. Hence the unsightly mess of grease surrounding the inner side of the axle flange and even the wheel center on tractors that are liberally greased. The text in the appropriate section of the op manual I have here supports this.

 

[jimg]

Yes, Im pretty sure about that....Im not w/ the tractor until Sat but IIRC it spins w/ the hub.

 

[Rowski]

There is only one seal, outboard of the outer bearing. Both outer and inner axle bearings are lubed by the transmission/hydraulic fluid. My understanding is the grease fills a void between the axle shaft flange and the axle seal, effectively protecting the seal with a layer of grease around the outer radial face. Hence the unsightly mess of grease surrounding the inner side of the axle flange and even the wheel center on tractors that are liberally greased. The text in the appropriate section of the op manual I have here supports this.

Does the grease must come out between the inside axle flange and the outer side of the final drive housing before it gets into the hydraulic fluid?

 

[jimg]

The grease isnt lubricating anything then but rather acting as a simple seal/separator. If thats true then its very important to evenly apply the grease as per the manual. Still seems a strange design.

 

[Robert_in_NY]

From my experience, the grease will come out evenly around the axle without having to rotate the tire. Once I see the grease start to move on the back side I quit but the grease moves all at once.

 

[Rowski]

Not sure if the link works....


TN axle breakdown


It shows what we're talking about. I'm wondering if the seal is a double or triple lipped. That would allow grease in a cavity of the seal and not let it get into the bearing. I would like to think that a seal must be sealing in the hydraulic oil, not just the presesnce of grease keeping in the fluid??

When I posted earlier I assumed that the item labeled PAG.2 PAG.3 was a seal but its not, its a shim ordered by thickness.

ALso I noticed that the TN60 has smaller bearings and axles in the rear than the tn70 and larger.



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