front axle lubricant question

[Jay4200]

What kind of high pressure would you have in a front axle and where would it be coming from?

Gears squashing together at a zillion PSI.

JayC

 

[JOHNTHOMAS]

Gears squashing together at a zillion PSI.

JayC

Would that be PSI or RPM? Would they be exerting pressure on the fluid system or pressure against each other? Are the gears actually pushing against each other or just engaging gear to turn gear? How fast (RPMs) would those gears be turning if the tractor is moving at 5mph or even 10 mph? I guess I have a lot of questions for the front geared drive experts that get so determined that one lubricating fluid in the front gears is so much better than another one. Isn't it true that the front gears are precision cut to turn each other in a submersed bath of lubricant that has no pump or filter or pressure trying to destroy the lubricant? Enquiring minds want to know. Who has taken the front gears all apart and looked at what's there??? Who's making it up as they go or just think they know how it works?:

 

[Ken]

Would that be PSI or RPM? Would they be exerting pressure on the fluid system or pressure against each other? Are the gears actually pushing against each other or just engaging gear to turn gear? How fast (RPMs) would those gears be turning if the tractor is moving at 5mph or even 10 mph? I guess I have a lot of questions for the front geared drive experts that get so determined that one lubricating fluid in the front gears is so much better than another one. Isn't it true that the front gears are precision cut to turn each other in a submersed bath of lubricant that has no pump or filter or pressure trying to destroy the lubricant? Enquiring minds want to know. Who has taken the front gears all apart and looked at what's there??? Who's making it up as they go or just think they know how it works?:

John I have taken the front apart on a L3600 and there is not much diffferance in design on other styles.
My reason for the disassembly was building a 180 foot barn and the operator left it in 4 whl drive on concrete hauling material into the barn . right side bearing gave away. as well as the pinion shaft gears and the housing attachment to frame. So the housing is not repairable needed new housing.
the gears look like stamped by a cookie cutter.and designed so any any metal floating or migrating to lowest level needs to go past the bearings. when ordering parts be sure to refill the checkbook 1st.

now as to the weight of oil book states use either.the rubber bands for seals thicker oil less likely to leak.
there is a metal cap at bottom of axle hubs carefully remove and look for metal grindings if so remember they went threw the bearings
Did this help the enquiring mind in making a decision . And not making this up. And know what I know.
ken

 

[Danner]

What kind of high pressure would you have in a front axle and where would it be coming from?

Torque being transferred from gear surface to gear surface. The local pressures on the lubricant are very high. Failure here wears the gears.

 

[ovrszd]

When I change I use 80-90w. I say Kubota uses UDT at the factory for simplicity. I also say they recommend either because they know 80-90w will work just as well and is warranty covered. But if they can suck you into buying their overpriced UDT, cha-ching for them.

 

[Bluegill2]

I'll be changing the L3800 to 80W-90 soon.

Yes, I've had the front-end apart on our old L3750. Very expensive rebuild!

 

[JOHNTHOMAS]

Thanks for the experienced replies. Are the gears/bearings immersed in lubricant or is it being squirted across the gears/bearings with some getting on them?

 

[ovrszd]

Thanks for the experienced replies. Are the gears/bearings immersed in lubricant or is it being squirted across the gears/bearings with some getting on them?

Same principle as your car/truck drive axle, splash system where oil is carried by the gears up into the case and then channeled by casing moldings to the bearing areas.

 

[Jeff F.]

I still do not understand where the oil pressure is coming from or why you would need to relieve pressure on the front drive by opening a cap. Is it the air pressure? I thought it is an oil bath system. I understand the pressure of the friction of metal on metal in the gears, but I do not understand how that would build up in the sealed front end. :confused3:

 

[sw03]

I still do not understand where the oil pressure is coming from or why you would need to relieve pressure on the front drive by opening a cap. Is it the air pressure? I thought it is an oil bath system. I understand the pressure of the friction of metal on metal in the gears, but I do not understand how that would build up in the sealed front end. :confused3:

called heat from amb temps or friction or both